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  Subjects -> VETERINARY SCIENCE (Total: 215 journals)
Showing 1 - 63 of 63 Journals sorted alphabetically
Acta Scientiae Veterinariae     Open Access   (Followers: 1)
Acta Veterinaria     Open Access   (Followers: 1)
Acta Veterinaria Brasilica     Open Access  
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 2)
Acta Veterinaria Scandinavica     Open Access   (Followers: 1)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 9)
Advances in Small Animal Medicine and Surgery     Hybrid Journal  
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 13)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 12)
African Journal of Wildlife Research     Full-text available via subscription   (Followers: 1)
Alexandria Journal of Veterinary Sciences     Open Access  
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 8)
American Journal of Primatology     Hybrid Journal   (Followers: 11)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 21)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 3)
Animal Behaviour     Hybrid Journal   (Followers: 109)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5)
Animal Health Research Reviews     Hybrid Journal   (Followers: 3)
Animal Nutrition     Open Access   (Followers: 8)
Animal Reproduction     Open Access   (Followers: 1)
Animal Reproduction Science     Hybrid Journal   (Followers: 4)
Animals     Open Access   (Followers: 7)
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Hybrid Journal   (Followers: 6)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 7)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access  
Arquivos de Ciências Veterinárias e Zoologia da UNIPAR     Open Access  
Ars Veterinaria     Open Access  
Asian Journal of Medical and Biological Research     Open Access   (Followers: 1)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Atatürk Üniversitesi Veteriner Bilimleri Dergisi     Open Access  
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 3)
Australian Veterinary Journal     Hybrid Journal   (Followers: 15)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 5)
Avian Pathology     Hybrid Journal   (Followers: 2)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access   (Followers: 2)
Bangladesh Veterinarian     Open Access  
BMC Veterinary Research     Open Access   (Followers: 10)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 8)
Buletin Peternakan : Bulletin of Animal Science     Full-text available via subscription  
Buletin Veteriner Udayana     Open Access  
Bulletin of Animal Health and Production in Africa     Full-text available via subscription   (Followers: 1)
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 8)
Case Reports in Veterinary Medicine     Open Access   (Followers: 5)
Ciência Animal Brasileira     Open Access  
Ciência Rural     Open Access   (Followers: 2)
Cogent Food & Agriculture     Open Access  
Companion Animal     Full-text available via subscription   (Followers: 9)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 4)
Equine Health     Full-text available via subscription   (Followers: 3)
Equine Veterinary Education     Hybrid Journal   (Followers: 9)
Equine Veterinary Journal     Hybrid Journal   (Followers: 13)
Ethiopian Veterinary Journal     Open Access   (Followers: 5)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
FAVE Sección Ciencias Veterinarias     Open Access  
Folia Veterinaria     Open Access  
Frontiers in Veterinary Science     Open Access   (Followers: 1)
Global Journal of Animal Scientific Research     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 6)
ILAR Journal     Hybrid Journal  
In Practice     Full-text available via subscription   (Followers: 2)
Indian Journal of Animal Sciences     Open Access   (Followers: 5)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 4)
Indonesia Medicus Veterinus     Open Access  
Intas Polivet     Full-text available via subscription   (Followers: 1)
International Journal for Agro Veterinary and Medical Sciences     Open Access   (Followers: 2)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 4)
Iranian Journal of Applied Animal Science     Open Access  
Irish Veterinary Journal     Open Access   (Followers: 5)
İstanbul Üniversitesi Veteriner Fakültesi Dergisi     Open Access  
Journal of Veterinary Science & Technology     Open Access   (Followers: 6)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 5)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 1)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Animal Science and Technology     Open Access  
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 5)
Journal of Buffalo Science     Hybrid Journal  
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 11)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 3)
Journal of Experimental and Applied Animal Sciences     Open Access   (Followers: 1)
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 4)
Journal of Research in Forestry, Wildlife and Environment     Open Access   (Followers: 3)
Journal of Small Animal Practice     Hybrid Journal   (Followers: 11)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 29)
Journal of the Selva Andina Research Society     Open Access   (Followers: 1)
Journal of the South African Veterinary Association     Open Access   (Followers: 2)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 4)
Journal of Veterinary Advances     Open Access   (Followers: 4)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 4)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 7)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 8)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 16)
Journal of Veterinary Internal Medicine     Open Access   (Followers: 19)
Journal of Veterinary Medical Education     Partially Free   (Followers: 10)
Journal of Veterinary Medicine     Open Access   (Followers: 8)
Journal of Veterinary Medicine and Animal Health     Open Access   (Followers: 4)
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 8)
Journal of Veterinary Research     Open Access  
Journal of Veterinary Science & Medical Diagnosis     Hybrid Journal   (Followers: 4)
Journal of Zoo and Aquarium Research     Open Access   (Followers: 2)
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 6)
Jurnal Agripet     Open Access  
Kenya Veterinarian     Full-text available via subscription   (Followers: 2)
kleintier konkret     Hybrid Journal  
Livestock     Full-text available via subscription   (Followers: 1)
Macedonian Veterinary Review     Open Access   (Followers: 2)
Media Peternakan - Journal of Animal Science and Technology     Open Access   (Followers: 1)
Medical Mycology     Open Access   (Followers: 2)
Medical Mycology Case Reports     Open Access  
Microbes and Health     Open Access   (Followers: 1)
New Zealand Veterinary Journal     Full-text available via subscription   (Followers: 11)
New Zealand Veterinary Nurse     Full-text available via subscription   (Followers: 3)
Nigerian Veterinary Journal     Open Access  
Nutrición Animal Tropical     Open Access   (Followers: 1)
Onderstepoort Journal of Veterinary Research     Open Access   (Followers: 3)
Open Access Animal Physiology     Open Access   (Followers: 4)
Open Journal of Animal Sciences     Open Access   (Followers: 4)
Open Journal of Veterinary Medicine     Open Access   (Followers: 4)
Pesquisa Veterinária Brasileira     Open Access  
pferde spiegel     Hybrid Journal  
Polish Journal of Veterinary Sciences     Open Access   (Followers: 3)
Pratique Médicale et Chirurgicale de l'Animal de Compagnie     Full-text available via subscription  
Preventive Veterinary Medicine     Hybrid Journal   (Followers: 10)
REDVET. Revista Electrónica de Veterinaria     Open Access  
Reproduction in Domestic Animals     Hybrid Journal   (Followers: 1)
Research & Reviews : Journal of Veterinary Science and Technology     Full-text available via subscription   (Followers: 1)
Research in Veterinary Science     Hybrid Journal   (Followers: 10)
Research Journal of Veterinary Sciences     Open Access   (Followers: 9)
Revista Brasileira de Ciência Veterinária     Open Access  
Revista Brasileira de Higiene e Sanidade Animal     Open Access  
Revista Brasileira de Parasitologia Veterinaria     Open Access  
Revista Brasileira de Reprodução Animal     Open Access  
Revista Brasileira de Zootecnia     Open Access   (Followers: 2)
Revista Ciencia Animal     Open Access  
Revista Ciencias Veterinarias     Open Access  
Revista Científica     Open Access  
Revista Colombiana de Ciencias Pecuarias (Colombian journal of animal science and veterinary medicine)     Open Access   (Followers: 1)
Revista Complutense de Ciencias Veterinarias     Open Access  
Revista da Sociedade Brasileira de Ciência em Animais de Laboratório     Open Access  
Revista de Ciências Agroveterinárias     Open Access  
Revista de Educação Continuada em Medicina Veterinária e Zootecnia     Open Access  
Revista de Investigaciones Veterinarias del Perú     Open Access  
Revista de la Facultad de Medicina Veterinaria y de Zootecnia     Open Access   (Followers: 1)
Revista de Medicina Veterinaria     Open Access  
Revista de Salud Animal     Open Access  
Revista Mexicana de Ciencias Pecuarias     Open Access  
Revista MVZ Córdoba     Open Access  
Revista Veterinaria     Open Access  
Revue Marocaine des Sciences Agronomiques et Vétérinaires     Open Access  
SA Stud Breeder / SA Stoetteler     Full-text available via subscription  
Schweizer Archiv für Tierheilkunde     Hybrid Journal  
Scientific Journal of Animal Science     Open Access   (Followers: 3)
Scientific Journal of Veterinary Advances     Open Access   (Followers: 1)
Small Ruminant Research     Hybrid Journal   (Followers: 2)
Sokoto Journal of Veterinary Sciences     Open Access   (Followers: 1)
Spei Domus     Open Access  
Tanzania Veterinary Journal     Full-text available via subscription   (Followers: 1)
team.konkret     Open Access  
The Dairy Mail     Full-text available via subscription   (Followers: 3)
Theriogenology     Hybrid Journal   (Followers: 1)
Topics in Companion Animal Medicine     Hybrid Journal   (Followers: 3)
Transboundary and Emerging Diseases     Hybrid Journal   (Followers: 2)
Trends in Animal and Veterinary Sciences     Open Access   (Followers: 5)
Trends in Parasitology     Full-text available via subscription   (Followers: 7)
Tropical Animal Health and Production     Hybrid Journal  
Tropical Veterinarian     Full-text available via subscription   (Followers: 1)
Turkish Journal of Veterinary and Animal Sciences     Open Access  
veterinär spiegel     Hybrid Journal   (Followers: 1)
Veterinária e Zootecnia     Open Access  
Veterinária em Foco     Open Access  
Veterinaria México     Open Access  
Veterinária Notícias     Open Access  
Veterinary Anaesthesia and Analgesia     Hybrid Journal   (Followers: 11)
Veterinary and Comparative Oncology     Hybrid Journal   (Followers: 7)
Veterinary Clinical Pathology     Hybrid Journal   (Followers: 9)
Veterinary Clinics of North America: Equine Practice     Full-text available via subscription   (Followers: 9)
Veterinary Clinics of North America: Exotic Animal Practice     Full-text available via subscription   (Followers: 7)
Veterinary Clinics of North America: Food Animal Practice     Full-text available via subscription   (Followers: 5)
Veterinary Clinics of North America: Small Animal Practice     Full-text available via subscription   (Followers: 15)
Veterinary Dermatology     Hybrid Journal   (Followers: 7)
Veterinary Immunology and Immunopathology     Hybrid Journal   (Followers: 9)
Veterinary Journal     Hybrid Journal   (Followers: 15)
Veterinary Medicine and Animal Sciences     Open Access   (Followers: 3)
Veterinary Medicine and Science     Open Access  
Veterinary Medicine International     Open Access   (Followers: 7)
Veterinary Medicine: Research and Reports     Open Access   (Followers: 4)
Veterinary Microbiology     Hybrid Journal   (Followers: 8)
Veterinary Nurse     Full-text available via subscription   (Followers: 4)
Veterinary Nursing Journal     Hybrid Journal   (Followers: 3)
Veterinary Ophthalmology     Hybrid Journal   (Followers: 6)
Veterinary Parasitology     Hybrid Journal   (Followers: 9)
Veterinary Pathology     Full-text available via subscription   (Followers: 14)

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Journal Cover Domestic Animal Endocrinology
  [SJR: 0.882]   [H-I: 53]   [4 followers]  Follow
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0739-7240
   Published by Elsevier Homepage  [2969 journals]
  • Moderate high or low maternal protein diets change gene expression but not
           the phenotype of skeletal muscle from porcine fetuses
    • Abstract: Publication date: Available online 16 August 2016
      Source:Domestic Animal Endocrinology
      Author(s): C. Kalbe, D. Lösel, J. Block, L. Lefaucheur, K.-P. Brüssow, O. Bellmann, R. Pfuhl, B. Puppe, W. Otten, C.C. Metges, C. Rehfeldt
      The aim of our study was to characterize the immediate phenotypic and adaptive regulatory responses of fetuses to different in utero conditions reflecting inadequate maternal protein supply during gestation. The gilts fed high (250% above control) or low (50% under control) protein diets isoenergetically adjusted at the expense of carbohydrates from the day of insemination until the fetuses were collected at d 64 or 94 of gestation. We analyzed body composition, histo-morphology, biochemistry, and mRNA expression of fetal skeletal muscle. Both diets had only marginal effects on body composition and muscular cellularity of fetuses including an unchanged total number of myofibers. However, mRNA expression of myogenic regulatory factors (MYOG, MRF4, P ≤ 0.1), IGF system (IGF1, IGF1R, P ≤ 0.05) and myostatin antagonist FST (P = 0.6, in males only) was reduced in the fetal muscle exposed to a maternal low protein diet. As a result of excess protein, MYOD, MYOG, IGF1R and IGFBP5 mRNA expression (P ≤ 0.05) was upregulated in fetal muscle. Differences in muscular mRNA expression indicate in utero regulatory adaptive responses to maternal diet. Modulation of gene expression immediately contributes to the maintenance of an appropriate fetal phenotype that would be similar to that observed in the control fetuses. Moreover, we suggest that the modified gene expression in fetal skeletal muscle can be viewed as the origin of developmental muscular plasticity involved in the concept of fetal programming.

      PubDate: 2016-08-21T22:47:47Z
  • A miRNA-target network putatively involved in follicular atresia
    • Abstract: Publication date: Available online 13 August 2016
      Source:Domestic Animal Endocrinology
      Author(s): F.X. Donadeu, J. Ioannidis
      In a previous microarray study we identified a subset of miRNAs which expression was distinctly higher in atretic than healthy follicles of cattle. In the present study we investigated the involvement of those miRNAs in granulosa and theca cells during atresia. RT-qPCR confirmed that miR-21-5p/-3p, miR-150, miR-409a, miR-142-5p, miR-378, miR-222, miR-155 and miR-199a-5p were expressed at higher levels in atretic than healthy follicles (9-17 mm, classified based on steroidogenic capacity). All miRNAs except miR-21-3p and miR-378 were expressed at higher levels in theca than granulosa cells. The expression of 13 predicted miRNA targets was determined in follicular cells by RT-qPCR, revealing downregulation of HIF1A, ETS1, JAG1, VEGFA and MSH2 in either or both cell types during atresia. Based on increases in miRNA levels simultaneous with decreases in target levels in follicular cells, several predicted miRNA-target interactions were confirmed that are putatively involved in follicular atresia, namely miR-199a-5p/miR-155-HIF1A in granulosa cells, miR-155/miR-222-ETS1 in theca cells, miR-199a-5p-JAG1 in theca cells, miR-199a-5p/miR-150/miR-378-VEGFA in granulosa and theca cells, and miR-155-MSH2 in theca cells. These results offer novel insight on the involvement of miRNAs in follicle development by identifying a miRNA-target network that is putatively involved in follicle atresia.

      PubDate: 2016-08-16T21:47:35Z
  • Effect of fish oil on lateral mobility of prostaglandin F2α (FP)
           receptors and spatial distribution of lipid microdomains in bovine luteal
           cell plasma membrane in vitro1
    • Abstract: Publication date: Available online 12 August 2016
      Source:Domestic Animal Endocrinology
      Author(s): Michele R. Plewes, Patrick D. Burns, Peter E. Graham, Richard M. Hyslop, B. George Barisas
      Lipid microdomains are ordered regions on the plasma membrane of cells, rich in cholesterol and sphingolipids, ranging in size from 10 to 200 nm in diameter. These lipid-ordered domains may serve as platforms to facilitate co-localization of intracellular signaling proteins during agonist-induced signal transduction. It is hypothesized that fish oil will disrupt the lipid microdomains, increasing spatial distribution of these lipid-ordered domains and lateral mobility of the prostaglandin (PG) F2α (FP) receptors in bovine luteal cells. The objectives of this study were to examine the effects of fish oil on 1) the spatial distribution of lipid microdomains, 2) lateral mobility of FP receptors and 3) lateral mobility of FP receptors in the presence of PGF2α on the plasma membrane of bovine luteal cells in vitro. Bovine ovaries were obtained from a local abattoir and corpora lutea were digested using collagenase. In Experiment 1, lipid microdomains were labeled using cholera toxin subunit B Alexa Fluor 555. Domains were detected as distinct patches on the plasma membrane of mixed luteal cells. Fish oil treatment decreased fluorescent intensity in a dose dependent manner (P < 0.01). In Experiment 2, single particle tracking was used to examine the effects of fish oil treatment on lateral mobility of FP receptors. Fish oil treatment increased micro- and macro-diffusion coefficients of FP receptors as compared to control cells (P < 0.05). In addition, compartment diameters of domains were larger and residence times were reduced for receptors in fish oil treated cells (P < 0.05). In Experiment 3, single particle tracking was used to determine the effects of PGF2α on lateral mobility of FP receptors and influence of fish oil treatment. Lateral mobility of receptors was decreased within 5 min following addition of ligand for control cells (P < 0.05). However, lateral mobility of receptors was unaffected by addition of ligand for fish oil treated cells (P > 0.10). The data presented provide strong evidence that fish oil causes a disruption in lipid microdomains and affects lateral mobility of FP receptors in the absence and presence of PGF2α.

      PubDate: 2016-08-12T20:59:21Z
  • Validation of different measures of insulin sensitivity of glucose
           metabolism in dairy cows using the hyperinsulinemic euglycemic clamp test
           as the gold standard
    • Abstract: Publication date: Available online 1 July 2016
      Source:Domestic Animal Endocrinology
      Author(s): J. De Koster, M. Hostens, K. Hermans, W. Van den Broeck, G. Opsomer
      The aim of the present research was to compare different measures of insulin sensitivity in dairy cows at the end of the dry period. To do so, 10 clinically healthy dairy cows with a varying body condition score were selected. By performing hyperinsulinemic euglycemic clamp (HEC) tests, we previously demonstrated a negative association between the insulin sensitivity and insulin responsiveness of glucose metabolism and the body condition score of these animals. In the same animals, other measures of insulin sensitivity were determined and the correlation with the HEC test, which is considered as the gold standard, was calculated. Measures derived from the intravenous glucose tolerance test (IVGTT) are based on the disappearance of glucose after an intravenous glucose bolus. Glucose concentrations during the IVGTT were used to calculate the area under the curve of glucose and the clearance rate of glucose. In addition, glucose and insulin data from the IVGTT were fitted in the minimal model to derive the insulin sensitivity parameter, Si. Based on blood samples taken before the start of the IVGTT, basal concentrations of glucose, insulin, NEFA, and β-hydroxybutyrate were determined and used to calculate surrogate indices for insulin sensitivity, such as the homeostasis model of insulin resistance, the quantitative insulin sensitivity check index, the revised quantitative insulin sensitivity check index and the revised quantitative insulin sensitivity check index including β-hydroxybutyrate. Correlation analysis revealed no association between the results obtained by the HEC test and any of the surrogate indices for insulin sensitivity. For the measures derived from the IVGTT, the area under the curve for the first 60 min of the test and the Si derived from the minimal model demonstrated good correlation with the gold standard.

      PubDate: 2016-08-03T14:10:17Z
  • Comparing the effects of heat stress and mastitis on ovarian function in
           lactating cows: basic and applied aspects
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): Z. Roth, D. Wolfenson
      Reduced reproductive performance of lactating cows is strongly associated with environmental and pathogenic stressors. This review summarizes the most recent knowledge on the effects of acute or chronic heat stress (HS) and acute or chronic intramammary infection (IMI) on ovarian function. It also offers various approaches for improving the fertility of cows under chronic HS or IMI. Comparing the 2 stressors reveals a few similarities in the mode of alteration in the hypothalamus–pituitary–ovarian axis, in particular, in the follicle and its enclosed oocyte. Both HS and IMI cause a reduction in the preovulatory LH surge, with a pronounced effect in cows with IMI, and consequently, ovulation is being delayed or inhibited. Both stresses induce changes in follicular growth dynamics, reduce follicular steroidogenesis, and disrupt follicular dominance. Unlike their effects on follicular function, the effects of mastitis and HS on corpus luteum (CL) function are debatable. Under chronic summer thermal stress, several, but not all, studies show reduced progesterone secretion by the CL. Subclinical mastitis does not affect CL function, whereas the effect of clinical mastitis is controversial; some show a reduction in progesterone, whereas others do not. Both stresses have been found to impair cytoplasmic and nuclear maturation of oocytes, associated with reduced embryonic development. These findings have provided insights into the mechanism by which HS and IMI compromise fertility, which enable developing new strategies to mitigate these effects. For instance, treatment with GnRH and PGF2α to induce follicular turnover successfully improved conception rate in subpopulations of HS cows during the summer, in particular, primiparous cows and cows with high BCS. The “Ovsynch” program, also based on the use of GnRH and PGF2α, has been shown to improve conception rate of subclinical mastitic cows, most likely due to better synchronization of timing of ovulation with that of AI. Supplementing progesterone after AI improves conception rate of HS cows, particularly those with postpartum uterine disease and low BCS. It should be noted that similarities between the 2 stressors do not necessarily suggest a shared mechanism. Although not clear enough, an additive deleterious effects of HS and IMI on reproduction is suggested.

      PubDate: 2016-08-03T14:10:17Z
  • Intrapituitary mechanisms underlying the control of fertility: key
           players in seasonal breeding
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): D.J. Tortonese
      Recent studies have shown that, in conjunction with dynamic changes in the secretion of GnRH from the hypothalamus, paracrine interactions within the pituitary gland play an important role in the regulation of fertility during the annual reproductive cycle. Morphological studies have provided evidence for close associations between gonadotropes and lactotropes and gap junction coupling between these cells in a variety of species. The physiological significance of this cellular interaction was supported by subsequent studies revealing the expression of prolactin receptors in both the pars distalis and pars tuberalis regions of the pituitary. This cellular interaction is critical for adequate gonadotropin output because, in the presence of dopamine, prolactin can negatively regulate the LH response to GnRH. Receptor signaling studies showed that signal convergence at the level of protein kinase C and phospholipase C within the gonadotrope underlies the resulting inhibition of LH secretion. Although this is a conserved mechanism present in all species studied so far, in seasonal breeders such as the sheep and the horse, this mechanism is regulated by photoperiod, as it is only apparent during the long days of spring and summer. At this time of year, the nonbreeding season of the sheep coincides with the breeding season of the horse, indicating that this inhibitory system plays different roles in short- and long-day breeders. Although in the sheep, it contributes to the complete suppression of the reproductive axis, in the horse, it is likely to participate in the fine-tuning of gonadotropin output by preventing gonadotrope desensitization. The photoperiodic regulation of this inhibitory mechanism appears to rely on alterations in the folliculostellate cell population. Indeed, electron microscopic studies have recently shown increased folliculostellate cell area together with upregulation of their adherens junctions during the spring and summer. The association between gonadotropes and lactotropes could also underlie an interaction between the gonadotropic and prolactin axes in the opposite direction. In support of this alternative, a series of studies have demonstrated that GnRH stimulates prolactin secretion in sheep through a mechanism that does not involve the mediatory actions of LH or FSH and that this stimulatory effect of GnRH on the prolactin axis is seasonally regulated. Collectively, these findings highlight the importance of intercellular communications within the pituitary in the control of gonadotropin and prolactin secretion during the annual reproductive cycle in seasonal breeders.

      PubDate: 2016-08-03T14:10:17Z
  • Local immune system in oviduct physiology and pathophysiology: attack or
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): M.A. Marey, M.S. Yousef, R. Kowsar, N. Hambruch, T. Shimizu, C. Pfarrer, A. Miyamoto
      The local immune system in the oviduct has a unique ability to deal with pathogens, allogeneic spermatozoa, and the semi-allogeneic embryo. To achieve this, it seems likely that the oviduct possesses an efficient and strictly controlled immune system that maintains optimal conditions for fertilization and early embryo development. The presence of a proper sperm and/or embryo-oviduct interaction begs the question of whether the local immune system in the oviduct exerts beneficial or deleterious effects on sperm and early embryo; support or attack'. A series of studies has revealed that bovine oviduct epithelial cells (BOECs) are influenced by preovulatory levels of Estradiol-17β, progesterone, and LH to maintain an immunologic homeostasis in bovine oviduct, via inhibition of proinflammatory responses that are detrimental to allogenic sperm. Under pathologic conditions, the mucosal immune system initiates the inflammatory response to the infection; the bacterial lipopolysaccharide (LPS) at low concentrations induces a proinflammatory response with increased expression of TLR-4, PTGS2, IL-1β, NFκB1, and TNFα, resulting in tissue damage. At higher concentrations, however, LPS induces a set of anti-inflammatory genes (TLR-2, IL-4, IL-10, and PTGES) that may initiate a tissue repair. This response of BOECs is accompanied by the secretion of acute phase protein, suggesting that BOECs react to LPS with a typical acute proinflammatory response. Under physiological conditions, polymorphonuclear neutrophils (PMN) are existent in the oviductal fluid during preovulatory period in the bovine. Interestingly, the bovine oviduct downregulates sperm phagocytosis by PMN via prostaglandin E2 (PGE2) action. In addition, the angiotensin-endothelin-PGE2 system controlling oviduct contraction may fine-tune the PMN phagocytic behavior to sperm in the oviduct. Importantly, a physiological range of PGE2 supplies anti-inflammatory balance in BOEC. Our recent results show that the sperm binding to BOECs further shift the local immunity toward anti-inflammatory conditions with upregulation of IL-10, TGFβ, and PGE2. In addition, this local environment leads PMN to express anti-inflammatory cytokines. In conclusion, the oviduct displays mucosal immunity that maintains an anti-inflammatory environment under physiological conditions that supports the sperm. Under pathologic condition, however, the oviduct supplies the innate immunity that may attack the sperm. Moreover, the oviduct-sperm interaction further suppresses the innate immune cells and strengthens the anti-inflammatory balance in the oviduct. Therefore, the oviduct immunity ensures sperm viability before fertilization.

      PubDate: 2016-08-03T14:10:17Z
  • Impact of nutritional programming on the growth, health, and sexual
           development of bull calves
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): H. Bollwein, F. Janett, M. Kaske
      The growth, health, and reproductive performance of bull calves are important prerequisites for a successful cattle breeding program. Therefore, several attempts have been made to improve these parameters via nutritional programming. Although an increase in energy uptake during the postweaning period (7–8 mo of age) of the calves leads to a faster growing rate, it has no positive effects on sexual development. In contrast, a high-nutrition diet during the prepubertal period (8–20 wk of age) reduced the age at puberty of the bulls and increased the size and/or weight of the testis and the epididymal sperm reserves. This faster sexual development is associated with an increased transient LH peak, which seems to be mediated by an increase in serum IGF-I concentrations. However, the exact mechanisms responsible for the interaction between nutrition and the subsequent development of the calves are not clear. The sexual development of bull calves depends not only on the nutrition of the calves after birth but also on the feed intake of their mothers during pregnancy. In contrast to the effects of the feed intake of the bull calves, a high-nutrition diet fed to the mother during the first trimester has negative effects on the reproductive performance of their offspring. In conclusion, it has been clearly demonstrated that growth, health, and reproductive performance can be improved by nutritional programming, but further studies are necessary to obtain a better understanding about the mechanisms responsible for this phenomenon.

      PubDate: 2016-08-03T14:10:17Z
  • New concepts of the central control of reproduction, integrating influence
           of stress, metabolic state, and season
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): I.J. Clarke, L. Arbabi
      Gonadotropin releasing hormone is the primary driver of reproductive function and pulsatile GnRH secretion from the brain causes the synthesis and secretion of LH and FSH from the pituitary gland. Recent work has revealed that the secretion of GnRH is controlled at the level of the GnRH secretory terminals in the median eminence. At this level, projections of kisspeptin cells from the arcuate nucleus of the hypothalamus are seen to be closely associated with fibers and terminals of GnRH cells. Direct application of kisspeptin into the median eminence causes release of GnRH. The kisspeptin cells are activated at the time of a natural “pulse” secretion of GnRH, as reflected in the secretion of LH. This appears to be due to input to the kisspeptin cells from glutamatergic cells in the basal hypothalamus, indicating that more than 1 neural element is involved in the secretion of GnRH. Because the GnRH secretory terminals are outside the blood–brain barrier, factors such as kisspeptin may be administered systemically to cause GnRH secretion; this offers opportunities for manipulation of the reproductive axis using factors that do not cross the blood-brain barrier. In particular, kisspeptin or analogs of the same may be used to activate reproduction in the nonbreeding season of domestic animals. Another brain peptide that influences reproductive function is gonadotropin inhibitory hormone (GnIH). Work in sheep shows that this peptide acts on GnRH neuronal perikarya, but projections to the median eminence also allow secretion into the hypophysial portal blood and action of GnIH on pituitary gonadotropes. GnIH cells are upregulated in anestrus, and infusion of GnIH can block the ovulatory surge in GnRH and/or LH secretion. Metabolic status may also affect the secretion of reproduction, and this could involve action of gut peptides and leptin. Neuropeptide Y and Y-receptor ligands have a negative impact on reproduction, and Neuropeptide Y production is markedly increased in negative energy balance; this may be the cause of lowered GnRH and gonadotropin secretion in this state. There is a complex interaction between appetite-regulating peptide neurons and kisspeptin neurons that enables the former to regulate the latter both positively and negatively. In terms of how GnRH secretion is reduced during stress, recent data indicate that GnIH cells are integrally involved, with increased input to the GnRH cells. The secretion of GnIH into the portal blood is not increased during stress, so the negative effect is most likely effected at the level of GnRH neuronal cell bodies.

      PubDate: 2016-08-03T14:10:17Z
  • Altering prolactin concentrations in sows
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): C. Farmer
      Prolactin has a multiplicity of actions, but it is of particular importance in gestating and lactating animals. In sows, it is involved in the control of mammary development and also holds essential roles in the lactogenic and galactopoietic processes. Furthermore, low circulating concentrations of prolactin are associated with the agalactia syndrome. The crucial role of prolactin makes it important to understand the various factors that can alter its secretion. Regulation of prolactin secretion is largely under the negative control of dopamine, and dopamine agonists consistently decrease prolactin concentrations in sows. On the other hand, injections of dopamine antagonists can enhance circulating prolactin concentrations. Besides pharmacologic agents, many other factors can also alter prolactin concentrations in sows. The use of Chinese-derived breeds, for instance, leads to increased prolactin concentrations in lactating sows compared with standard European white breeds. Numerous husbandry and feeding practices also have a potential impact on prolactin concentrations in sows. Factors, such as provision of nest-building material prepartum, housing at farrowing, high ambient temperature, stress, transient weaning, exogenous thyrotropin-releasing factor, exogenous growth hormone-releasing factor, nursing frequency, prolonged photoperiod, fasting, increased protein and/or energy intake, altered energy sources, feeding high-fiber diets, sorghum ergot or plant extracts, were all studied with respect to their prolactinemic properties. Although some of these practices do indeed affect circulating prolactin concentrations, none leads to changes as drastic as those brought about by dopamine agonists or antagonists. It appears that the numerous factors regulating prolactin concentrations in sows are still not fully elucidated, and that studies to develop novel applicable ways of increasing prolactin concentrations in sows are warranted.

      PubDate: 2016-08-03T14:10:17Z
  • Serotonin and calcium homeostasis during the transition period
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): S.R. Weaver, J. Laporta, S.A.E. Moore, L.L. Hernandez
      The transition from pregnancy to lactation puts significant, sudden demands on maternal energy and calcium reserves. Although most mammals are able to effectively manage these metabolic adaptations, the lactating dairy cow is acutely susceptible to transition-related disorders because of the high amounts of milk being produced. Hypocalcemia is a common metabolic disorder that occurs at the onset of lactation. Hypocalcemia is also known to result in poor animal welfare conditions. In addition, cows that develop hypocalcemia are more susceptible to a host of other negative health outcomes. Different feeding tactics, including manipulating the dietary cation-anion difference and administering low-calcium diets, are commonly used preventative strategies. Despite these interventions, the incidence of hypocalcemia in the subclinical form is still as high as 25% to 30% in the United States dairy cow population, with a 5% to 10% incidence of clinical hypocalcemia. In addition, although there are various effective treatments in place, they are administered only after the cow has become noticeably ill, at which point there is already significant metabolic damage. This emphasizes the need for developing alternative prevention strategies, with the monoamine serotonin implicated as a potential therapeutic target. Our research in rodents has shown that serotonin is critical for the induction of mammary parathyroid hormone–related protein, which is necessary for the mobilization of bone tissue and subsequent restoration of maternal calcium stores during lactation. We have shown that circulating serotonin concentrations are positively correlated with serum total calcium on the first day of lactation in dairy cattle. Administration of serotonin's immediate precursor through feeding, injection, or infusion to various mammalian species has been shown to increase circulating serotonin concentrations, with positive effects on other components of maternal metabolism. Most recently, preliminary data suggest that manipulation of the serotonergic axis precalving may positively affect postcalving calcium dynamics. Combined, our research suggests a potential mechanism by which serotonin acts on the mammary gland to maintain circulating maternal calcium concentrations. Further research into serotonin's potential as a therapeutic target could contribute significantly as a preventive strategy against hypocalcemia in early lactation dairy cows.

      PubDate: 2016-08-03T14:10:17Z
  • Glucocorticoid programming of intrauterine development
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): A.L. Fowden, O.A. Valenzuela, O.R. Vaughan, J.K. Jellyman, A.J. Forhead
      Glucocorticoids (GCs) are important environmental and maturational signals during intrauterine development. Toward term, the maturational rise in fetal glucocorticoid receptor concentrations decreases fetal growth and induces differentiation of key tissues essential for neonatal survival. When cortisol levels rise earlier in gestation as a result of suboptimal conditions for fetal growth, the switch from tissue accretion to differentiation is initiated prematurely, which alters the phenotype that develops from the genotype inherited at conception. Although this improves the chances of survival should delivery occur, it also has functional consequences for the offspring long after birth. Glucocorticoids are, therefore, also programming signals that permanently alter tissue structure and function during intrauterine development to optimize offspring fitness. However, if the postnatal environmental conditions differ from those signaled in utero, the phenotypical outcome of early-life glucocorticoid receptor overexposure may become maladaptive and lead to physiological dysfunction in the adult. This review focuses on the role of GCs in developmental programming, primarily in farm species. It examines the factors influencing GC bioavailability in utero and the effects that GCs have on the development of fetal tissues and organ systems, both at term and earlier in gestation. It also discusses the windows of susceptibility to GC overexposure in early life together with the molecular mechanisms and long-term consequences of GC programming with particular emphasis on the cardiovascular, metabolic, and endocrine phenotype of the offspring.

      PubDate: 2016-08-03T14:10:17Z
  • Adrenergic and noradrenergic regulation of poultry behavior and production
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): R.L. Dennis
      Norepinephrine and epinephrine (noradrenaline and adrenaline) are integral in maintaining behavioral and physiological homeostasis during both aversive and rewarding events. They regulate the response to stressful stimuli through direct activation of adrenergic receptors in the central and sympathetic nervous systems, hormonal activity and through the interaction of the brain, gut, and microbiome. The multiple functions of these catecholamines work synergistically to prepare an individual for a “fight or flight” response. However, hyper-reactivity of this system can lead to increased fearfulness and aggression, decreased health and productivity, and a reduction in overall well-being. Behaviors, such as aggression and certain fear-related behaviors, are a serious problem in the poultry industry that can lead to injury and cannibalism. For decades, catecholamines have been used as a measure of stress in animals. However, few studies have specifically targeted the adrenergic systems as means to reduce behaviors that are damaging or maladapted to their rearing environments and improve animal well-being. This article attempts to address our current understanding of specific, adrenergic-regulated behaviors that impact chicken well-being and production.

      PubDate: 2016-08-03T14:10:17Z
  • A comparison between the equine and bovine
           hypothalamus-pituitary-adrenocortical axis
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): J.H. van der Kolk, N. Fouché, J.J. Gross, V. Gerber, R.M. Bruckmaier
      In this review, we address the function of the hypothalamus-pituitary-adrenocortical (HPA) axis with special emphasis on the comparison between the bovine and equine species. The pars intermedia of the pituitary gland is particularly well developed in horses and cattle. However, its function is not well appreciated in cattle yet. The Wulzen's cone of the adenohypophysis is a special feature of ruminants. Total basal cortisol concentration is much higher in horses than that in cows with similar free cortisol fractions. Corticotropin-releasing factor (CRF) concentrations in equine pituitary venous blood are lower compared with other species, whereas plasma ACTH concentrations in cows are higher than those in horses. A CRF challenge test induced a more pronounced cortisol response in horses compared with cattle, whereas regarding ACTH challenge testing, the opposite seems true. Based on data from literature, the bovine species is characterized by relatively high basal blood CRF and ACTH and low cortisol and glucose concentrations. Obviously, further lowering of blood cortisol in cattle is easily prevented by the high sensitivity to ACTH, and as a consequence, subsequent increased gluconeogenesis prevents imminent hypoglycemia. Hypoglycemia is less likely in horses given their high muscle glycogen content and their relatively high cortisol concentration. When assessing HPA axis reactivity, response patterns to exogenous ACTH or CRH might be used as a reliable indicator of animal welfare status in cows and horses, respectively, although it is emphasized that considerable caution should be exercised in using measures of HPA activity solely to assess animal welfare.

      PubDate: 2016-08-03T14:10:17Z
  • Marine macroalgal extracts to maintain gut homeostasis in the weaning
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): T. Sweeney, J.V. O'Doherty
      The mammalian gastrointestinal tract (GIT) is a dynamic environment, where a symbiotic relationship exists between the resident microbiota and the digestive and immune systems of the host. The development of the immune system begins in-utero and is further developed after the colonization of the GIT with microbiota during birth and postnatal life. The early establishment of this relationship is fundamental to the development and long-term maintenance of gut homeostasis. Regulatory mechanisms ensure an appropriate level of immune reactivity in the gut to accommodate the presence of beneficial and dietary microorganisms, whereas allowing effective immune responses to clear pathogens. However, unfavorable alterations in the composition of the microbiota, known as dysbiosis, have been implicated in many conditions including post-weaning diarrhea in pigs. Weaning is a major critical period in pig husbandry. It involves complex dietary, social, and environmental stresses that interfere with gut development. Post-weaning complications in piglets are characterized by a reduction in-feed intake and growth, atrophy of small intestine architecture, upregulation of intestinal inflammatory cytokines, alterations in GIT microflora, diarrhea, and heightened susceptibility to infection. These challenges have been controlled with in-feed prophylactic antibiotics and dietary minerals. However, these strategies are under scrutiny because of their role in promoting multidrug resistant bacteria and the accumulation of minerals in the environment, respectively. Therefore, significant efforts are being made to identify natural alternatives to support homeostasis in the piglet GIT, in particular during the weaning period. Chemodiversity in nature; including microorganisms, terrestrial plants, seaweeds, and marine organisms, offers a valuable source for novel bioactives. In this review, we discuss the advances in our understanding of the immune mechanisms by which the dynamic interplay of the intestinal microbiota and its host normally favors a homeostatic, symbiotic relationship, and how feeding macroalgal bioactives in both the maternal diet and the piglet diet, can be used to support this symbiotic relationship in times of challenge.

      PubDate: 2016-08-03T14:10:17Z
  • Adrenomedullin regulates intestinal physiology and pathophysiology
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): S. Martínez-Herrero, A. Martínez
      Adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP) are 2 biologically active peptides produced by the same gene, ADM, with ubiquitous distribution and many physiological functions. Adrenomedullin is composed of 52 amino acids, has an internal molecular ring composed by 6 amino acids and a disulfide bond, and shares structural similarities with calcitonin gene-related peptide, amylin, and intermedin. The AM receptor consists of a 7-transmembrane domain protein called calcitonin receptor-like receptor in combination with a single transmembrane domain protein known as receptor activity–modifying protein. Using morphologic techniques, it has been shown that AM and PAMP are expressed throughout the gastrointestinal tract, being specially abundant in the neuroendocrine cells of the gastrointestinal mucosa; in the enterochromaffin-like and chief cells of the gastric fundus; and in the submucosa of the duodenum, ileum, and colon. This wide distribution in the gastrointestinal tract suggests that AM and PAMP may act as gut hormones regulating many physiological and pathologic conditions. To date, it has been proven that AM and PAMP act as autocrine/paracrine growth factors in the gastrointestinal epithelium, play key roles in the protection of gastric mucosa from various kinds of injury, and accelerate healing in diseases such as gastric ulcer and inflammatory bowel diseases. In addition, both peptides are potent inhibitors of gastric acid secretion and gastric emptying; they regulate the active transport of sugars in the intestine, regulate water and ion transport in the colon, modulate colonic bowel movements and small-intestine motility, improve endothelial barrier function, and stabilize circulatory function during gastrointestinal inflammation. Furthermore, AM and PAMP are antimicrobial peptides, and they contribute to the mucosal host defense system by regulating gut microbiota. To get a formal demonstration of the effects that endogenous AM and PAMP may have in gut microbiota, we developed an inducible knockout of the ADM gene. Using this model, we have shown, for the first time, that lack of AM/PAMP leads to changes in gut microbiota composition in mice. Further studies are needed to investigate whether this lack of AM/PAMP may have an impact in the development and/or progression of intestinal diseases through their effect on microbiota composition.

      PubDate: 2016-08-03T14:10:17Z
  • The gut microbiome as a virtual endocrine organ with implications for farm
           and domestic animal endocrinology
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): T.F. O'Callaghan, R.P. Ross, C. Stanton, G. Clarke
      The gut microbiome exerts a marked influence on host physiology, and manipulation of its composition has repeatedly been shown to influence host metabolism and body composition. This virtual endocrine organ also has a role in the regulation of the plasma concentrations of tryptophan, an essential amino acid and precursor to serotonin, a key neurotransmitter within both the enteric and central nervous systems. Control over the hypothalamic-pituitary-adrenal axis also appears to be under the influence of the gut microbiota. This is clear from studies in microbiota-deficient germ-free animals with exaggerated responses to psychological stress that can be normalized by monocolonization with certain bacterial species including Bifidobacterium infantis. Therapeutic targeting of the gut microbiota may thus be useful in treating or preventing stress-related microbiome-gut-brain axis disorders and metabolic diseases, much the same way as redirections of metabolopathies can be achieved through more traditional endocrine hormone-based interventions. Moreover, the implications of these findings need to be considered in the context of farm and domestic animal physiology, behavior, and food safety.

      PubDate: 2016-08-03T14:10:17Z
  • Glucagon-like peptide 2 and its beneficial effects on gut function and
           health in production animals
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): E.E. Connor, C.M. Evock-Clover, E.H. Wall, R.L. Baldwin, M. Santin-Duran, T.H. Elsasser, D.M. Bravo
      Numerous endocrine cell subtypes exist within the intestinal mucosa and produce peptides contributing to the regulation of critical physiological processes including appetite, energy metabolism, gut function, and gut health. The mechanisms of action and the extent of the physiological effects of these enteric peptides are only beginning to be uncovered. One peptide in particular, glucagon-like peptide 2 (GLP-2) produced by enteroendocrine L cells, has been fairly well characterized in rodent and swine models in terms of its ability to improve nutrient absorption and healing of the gut after injury. In fact, a long-acting form of GLP-2 recently has been approved for the management and treatment of human conditions like inflammatory bowel disease and short bowel syndrome. However, novel functions of GLP-2 within the gut continue to be demonstrated, including its beneficial effects on intestinal barrier function and reducing intestinal inflammation. As knowledge continues to grow about GLP-2's effects on the gut and its mechanisms of release, the potential to use GLP-2 to improve gut function and health of food animals becomes increasingly more apparent. Thus, the purpose of this review is to summarize: (1) the current understanding of GLP-2's functions and mechanisms of action within the gut; (2) novel applications of GLP-2 (or stimulators of its release) to improve general health and production performance of food animals; and (3) recent findings, using dairy calves as a model, that suggest the therapeutic potential of GLP-2 to reduce the pathogenesis of intestinal protozoan infections.

      PubDate: 2016-08-03T14:10:17Z
  • Endogenous and exogenous factors influencing the concentrations of
           adiponectin in body fluids and tissues in the bovine
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): Helga Sauerwein, Susanne Häußler
      Adiponectin, one of the messenger molecules secreted from adipose tissue that are collectively termed adipokines, has been demonstrated to play a central role in lipid and glucose metabolism in humans and laboratory rodents; it improves insulin sensitivity and exerts antidiabetic and antiinflammatory actions. Adiponectin is synthesized as a 28 kDa monomer but is not secreted as such; instead, it is glycosylated and undergoes multimerization to form different molecular weight multimers before secretion. Adiponectin is one of the most abundant adipokines (μg/mL range) in the circulation. The concentrations are negatively correlated with adipose depot size, in particular with visceral fat mass in humans. Adiponectin exerts its effects by activating a range of different signaling molecules via binding to 2 transmembrane receptors, adiponectin receptor 1 and adiponectin receptor 2. The adiponectin receptor 1 is expressed primarily in the skeletal muscle, whereas adiponectin receptor 2 is predominantly expressed in the liver. Many of the functions of adiponectin are relevant to growth, lactation, and health and are thus of interest in both beef and dairy production systems. Studies on the role of the adiponectin protein in cattle have been impeded by the lack of reliable assays for bovine adiponectin. Although there are species-specific bovine adiponectin assays commercially available, they suffer from a lack of scientific peer-review of validity. Quantitative data about the adiponectin protein in cattle available in the literature emerged only during the last 3 yr and were largely based on Western blotting using either antibodies against human adiponectin or partial peptides from the bovine sequence. Using native bovine high–molecular-weight adiponectin purified from serum, we were able to generate a polyclonal antiserum that can be used for Western blot but also in an ELISA system, which was recently validated. The objective of this review is to provide an overview of the literature about the adiponectin protein in cattle addressing the following aspects: (1) the course of the adiponectin serum concentrations during development in both sexes, during inflammation, nutritional energy deficit and energy surplus, and lactation-induced changes including the response to supplementation with conjugated linoleic acids and with niacin, (2) the concentrations of adiponectin in subcutaneous vs visceral fat depots of dairy cows, (3) the protein expression of adiponectin in tissues other than adipose, and (4) the concentrations in different body fluids including milk.

      PubDate: 2016-08-03T14:10:17Z
  • Mechanisms of protein balance in skeletal muscle
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): T.G. Anthony
      Increased global demand for adequate protein nutrition against a backdrop of climate change and concern for animal agriculture sustainability necessitates new and more efficient approaches to livestock growth and production. Anabolic growth is achieved when rates of new synthesis exceed turnover, producing a positive net protein balance. Conversely, deterioration or atrophy of lean mass is a consequence of a net negative protein balance. During early life and periods of growth, muscle mass is driven by increases in protein synthesis at the level of mRNA translation. Throughout life, muscle mass is further influenced by degradative processes such as autophagy and the ubiquitin proteasome pathway. Multiple signal transduction networks guide and coordinate these processes alongside quality control mechanisms to maintain protein homeostasis (proteostasis). Genetics, hormones, and environmental stimuli each influence proteostasis control, altering capacity and/or efficiency of muscle growth. An overview of recent findings and current methods to assess muscle protein balance and proteostasis is presented. Current efforts to identify novel control points have the potential through selective breeding design or development of hormetic strategies to better promote growth and health span during environmental stress.

      PubDate: 2016-08-03T14:10:17Z
  • Host-targeted approaches to managing animal health: old problems and new
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): M.E. Cook, D.E. Bütz, M. Yang, J.M. Sand
      Our fellow medical and regulatory scientists question the animal producer's dependence on antibiotics and antimicrobial chemicals in the production of animal products. Retail distributors and consumers are putting even more pressure on the animal industry to find new ways to produce meat without antibiotics and chemicals. In addition, federal funding agencies are increasingly pressuring researchers to conduct science that has application. In the review that follows, we outline our approach to finding novel ways to improve animal performance and health. We use a strict set of guidelines in our applied research as follows: (1) Does the work have value to society' (2) Does our team have the skills to innovate in the field' (3) Is the product we produce commercially cost-effective' (4) Are there any reasons why the general consumer will reject the technology' (5) Is it safe for the animal, consumer, and the environment' Within this framework, we describe 4 areas of research that have produced useful products, areas that we hope other scientists will likewise explore and innovate such as (1) methods to detect infection in herds and flocks, (2) methods to control systemic and mucosal inflammation, (3) improvements to intestinal barrier function, and (4) methods to strategically potentiate immune defense. We recognize that others are working in these areas, using different strategies, but believe our examples will illustrate the vast opportunity for research and innovation in a world without antibiotics. Animal scientists have been given a new challenge that may help shape the future of both animal and human medicine.

      PubDate: 2016-08-03T14:10:17Z
  • Prostaglandin synthesis by the porcine corpus luteum: effect of tumor
           necrosis factor-α
    • Abstract: Publication date: Available online 15 July 2016
      Source:Domestic Animal Endocrinology
      Author(s): J. Chang, S. Frandsen, J.E. Gadsby
      The porcine corpus luteum (CL) displays delayed sensitivity to PGF-2α (luteolytic sensitivity, [LS]) until days 12 to 13 of cycle. The control of LS is unknown, but it is temporally associated with macrophage (which secrete TNF-α) infiltration into the CL. Other studies showed that TNF-α induces LS in vitro and that prostaglandins may be involved in this mechanism. In experiment 1, PGF-2α and PGE secretion by luteal cells (LCs) was measured on days 4 to 14 of the estrous cycle, and the expression of PTGFS/AKR1B1 and PTGES/mPGES-1, by Western blot, before (day 7) vs after (day 13) the onset of LS. Results showed that the PGF-2α:PGE ratio increased significantly (P < 0.05) from day 4 to 13–14, and PTGFS/AKR1B1 and PTGES/mPGES-1 were significantly increased (P < 0.05) on day 13 (vs day 7). In experiment 2, LCs were collected from porcine CL at early (∼days 4–6) or mid (∼days 7–12) stages of the estrous cycle and cultured with 0, 0.1, 1, or 10-ng/mL TNF-α. Results showed that TNF-α significantly increased (P < 0.05) messenger RNA (mRNA) expression of cyclooxygenase (COX)-2 and mPGES-1 but not AKR1B1. TNF-α had no significant effects on AKR1B1 or mPGES protein abundance. TNF-α significantly increased (P < 0.05) PGE-2 but had no effect on PGF2αs secretion or on the PGF2α:PGE2 ratio. In conclusion, although TNF-α increased COX2 and mPGES-1 mRNA, and PGE-2 secretion in vitro, it did not increase the PGF2α:PGE2 ratio. Studies are currently directed toward exploring other pathways (eg, FP receptor signaling) by which TNF-α induces LS in the porcine CL.

      PubDate: 2016-08-03T14:10:17Z
  • Editorial Board
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement

      PubDate: 2016-08-03T14:10:17Z
  • Table of Contents
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement

      PubDate: 2016-08-03T14:10:17Z
  • Endogenous and dietary lipids influencing feed intake and energy
           metabolism of periparturient dairy cows
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56, Supplement
      Author(s): B. Kuhla, C.C. Metges, H.M. Hammon
      The high metabolic priority of the mammary gland for milk production, accompanied by limited feed intake around parturition results in a high propensity to mobilize body fat reserves. Under these conditions, fuel selection of many peripheral organs is switched, for example, from carbohydrate to fat utilization to spare glucose for milk production and to ensure partitioning of tissue- and dietary-derived nutrients toward the mammary gland. For example, muscle tissue uses nonesterified fatty acids (NEFA) but releases lactate and amino acids in a coordinated order, thereby providing precursors for milk synthesis or hepatic gluconeogenesis. Tissue metabolism and in concert, nutrient partitioning are controlled by the endocrine system involving a reduction in insulin secretion and systemic insulin sensitivity and orchestrated changes in plasma hormones such as insulin, adiponectin, insulin growth factor-I, growth hormone, glucagon, leptin, glucocorticoids, and catecholamines. However, the endocrine system is highly sensitive and responsive to an overload of fatty acids no matter if excessive NEFA supply originates from exogenous or endogenous sources. Feeding a diet containing rumen-protected fat from late lactation to calving and beyond exerts similar negative effects on energy intake, glucose and insulin concentrations as does a high extent of body fat mobilization around parturition in regard to the risk for ketosis and fatty liver development. High plasma NEFA concentrations are thought not to act directly at the brain level, but they increase the energy charge of the liver which is, signaled to the brain to diminish feed intake. Cows differing in fat mobilization during the transition phase differ in their hepatic energy charge, whole body fat oxidation, glucose metabolism, plasma ghrelin, and leptin concentrations and in feed intake several week before parturition. Hence, a high lipid load, no matter if stored, mobilized or fed, affects the endocrine system, metabolism, and feed intake, and increases the risk for metabolic disorders. Future research should focus on a timely parallel increase in feed intake and milk yield during early lactation to reduce the impact of body fat on feed intake, metabolic health, and negative energy balance.

      PubDate: 2016-08-03T14:10:17Z
  • Expression of progesterone receptor in the porcine uterus and placenta
           throughout gestation: correlation with expression of uteroferrin and
    • Abstract: Publication date: Available online 15 July 2016
      Source:Domestic Animal Endocrinology
      Author(s): C.B. Steinhauser, F.W. Bazer, R.C. Burghardt, G.A. Johnson
      Progesterone (P4) stimulates production and secretion of histotroph, a mixture of hormones, growth factors, nutrients, and other substances required for growth and development of the conceptus (embryo/fetus and placental membranes). Progesterone acts through the progesterone receptor (PGR); however, there is a gap in our understanding of P4 during pregnancy because PGR have not been localized in the uteri and placentae of pigs beyond day 18. Therefore, we determined endometrial expression of PGR messenger RNA (mRNA) and localized PGR protein in uterine/placental tissues throughout the estrous cycle and through day 85 of pregnancy in pigs. Further, 2 components of histotroph, tartrate-resistant acid phosphatase 5 (ACP5; uteroferrin) and secreted phosphoprotein 1 (SPP1; osteopontin) proteins, were localized in relation to PGR during pregnancy. Endometrial expression of PGR mRNA was highest at day 5 of the estrous cycle, decreased between days 5 and 11 of both the estrous cycle and pregnancy, and then increased between days 11 and 17 of the estrous cycle (P < 0.01), but decreased from days 13 to 40 of pregnancy (P < 0.01). Progesterone receptor protein localized to uterine stroma and myometrium throughout all days of the estrous cycle and pregnancy. PGR were expressed by uterine luminal epithelium (LE) between days 5 and 11 of the estrous cycle and pregnancy, then PGR became undetectable in LE through day 85 of pregnancy. During the estrous cycle, PGR were downregulated in LE between days 11 and 15, but expression returned to LE on day 17. All uterine glandular epithelial (GE) cells expressed PGR from days 5 to 11 of the estrous cycle and pregnancy, but expression decreased in the superficial GE by day 12. Expression of PGR in GE continued to decrease between days 25 and 85 of pregnancy; however, a few glands near the myometrium and in close proximity to areolae maintained expression of PGR protein. Acid phosphatase 5 protein was detected in the GE from days 12 to 85 of gestation and in areolae. Secreted phosphoprotein 1 protein was detected in uterine LE in apposition to interareolar, but not areolar areas of the chorioallantois on all days examined, and in uterine GE between days 35 and 85 of gestation. Interestingly, uterine GE cells adjacent to areolae expressed PGR, but not ACP5 or SPP1, suggesting these are excretory ducts involved in the passage, but not secretion, of histotroph into the areolar lumen and highlighting that P4 does not stimulate histotroph production in epithelial cells that express PGR.

      PubDate: 2016-08-03T14:10:17Z
  • Development of the independent function of fetal thyroid glands in the dog
           in connection with iodothyronine concentrations in pregnant bitches, fetal
           fluids and fetal serum
    • Abstract: Publication date: Available online 21 July 2016
      Source:Domestic Animal Endocrinology
      Author(s): J. Thuróczy, J. Szilágyi, L. Müller, L. Balogh
      Thyroxine (T4) and triiodothyronine (T3) concentrations in pregnant and non-pregnant bitches were measured. The allantoic and amniotic fluid samples were collected separately in the third week of pregnancy and fetal blood samples were collected in the fourth week of pregnancy. There was no difference between T4 results in the pregnant and non-pregnant animals, but the measured serum concentrations exceeded the healthy range for normal adults. Serum T4 concentrations were lower in the fetus than in adults (P < 0.01). Fetal T4 concentrations continuously increased and reached 13.38 ± 6.19 nmol/L before birth. The fetal serum T4 concentrations were lower than the T4 concentrations in allantoic and amniotic fluid until the seventh week and the fetal serum T3 concentrations were lower than in fetal fluids throughout the pregnancy (P < 0.01). Maximum T3 concentrations in allantoic and amniotic fluid exceeded the concentrations in the fetal and maternal serum. It is conceivable that the considerable differences between maternal and fetal serum T4 concentrations in healthy animals are explained by the T4 impermeability of the placenta. Extremely high maternal T4 (193.5 nmol/L) in one bitch was associated with T4 concentrations under the detection limit in the fetal fluids and serum suggesting an inhibitory effect. The T4 concentrations in all of the fetal fluids and serum were under the detectable concentration that can be defined by 3.0 nmol/L in that bitch. We have demonstrated that fetal thyroid glands start functioning independently at the same time as thyroid cell formation in the dog, but the overproduction of maternal T4 may have a suppressive effect on fetal iodothyronine production.

      PubDate: 2016-08-03T14:10:17Z
  • Prolactin role in the bovine uterus during adenomyosis
    • Abstract: Publication date: Available online 25 July 2016
      Source:Domestic Animal Endocrinology
      Author(s): M. Łupicka, B.M. Socha, A.A. Szczepańska, A.J. Korzekwa
      Adenomyosis is uterine dysfunction defined as the presence of endometrial glands within the myometrium. It is suggested that adenomyosis is oestrogen-dependent pathology, and prolactin (PRL) also affects its development. In the uterus of ruminants, PRL stimulates gland proliferation and function. We hypothesised that in the bovine uterus, expression of PRL and its receptors (PRLRs) during adenomyosis is disturbed and modulated by oestradiol (E2). Uterine tissues were collected post mortem from cows; epithelial, stromal and myometrial cells were isolated; and cultured and treated with E2. Material was divided into two groups: control (non-adenomyotic) and uteri with adenomyosis. In adenomyotic uterine tissue, PRL and its long-form receptor (lPRLR) protein were increased, as determined by western blotting. Immunohistostaining showed that during adenomyosis, PRL and its receptors are highly expressed in adenomyotic lesions. In cultured myometrial cells, protein expression of PRL and its receptors was increased during adenomyosis. Oestradiol decreased PRLRs protein expression in non-adenomyotic stromal cells and in adenomyotic myometrial cells, and increased PRL secretion by adenomyotic myometrial cells. Moreover, PRL secretion was increased in untreated epithelial and stromal cells during adenomyosis. On the other hand, in stromal cells, PRLRs mRNA and protein expression was decreased, as determined by real-time PCR and western blotting, respectively. Obtained results show that significant changes in PRL and PRLRs expression are observed in uterine tissue and cells during adenomyosis, which were also affected by E2. These data suggest involvement of PRL in adenomyosis development and the link between PRL and E2 actions during the dysfunction in cows.

      PubDate: 2016-08-03T14:10:17Z
  • Preface: Eighth International Conference on Farm Animal Endocrinology
    • Abstract: Publication date: Available online 20 May 2016
      Source:Domestic Animal Endocrinology
      Author(s): Mogens Vestergaard, Rupert Bruckmaier, Akio Miyamoto

      PubDate: 2016-06-18T18:51:23Z
  • Characteristics, tissue-specific expression, and hormonal regulation of
           expression of tyrosine aminotransferase in the avian female reproductive
    • Abstract: Publication date: October 2016
      Source:Domestic Animal Endocrinology, Volume 57
      Author(s): W. Lim, G. Song
      Tyrosine aminotransferase (TAT) catalyzes the transamination of tyrosine to p-hydroxyphenylpyruvate. Accumulation of tyrosine in the body due to a genetic mutation in the TAT gene causes tyrosomia type II in humans. The TAT gene is regarded as a model for studying steroid-inducible factors regulating a variety of biological functions of TAT. However, little is known of the effects of estrogen on the expression of the TAT gene in chickens. Therefore, in the present study, we identified expression of the avian TAT gene in various organs. The results showed the TAT was detected predominantly in the liver and reproductive organs including testis, oviduct, and ovary. Specifically, TAT mRNA was expressed abundantly in the glandular and luminal epithelia of the oviducts in response to endogenous and exogenous estrogens which also induce dramatic morphological changes in the oviduct of chickens. In addition, target microRNAs of TAT (miR-1460, miR-1626-3p, miR-1690-5p, and miR-7442-3p) were found to modulate expression of the TAT gene. Especially, miR-1690-5p influenced TAT gene transcription by binding directly to its 3′-UTR region. Moreover, the expression of TAT was abundant in glandular epithelia of cancerous but not normal ovaries from laying hens. Taken together, our findings suggest that TAT plays an important role in the cytodifferentiation of oviducts in response to estrogen and in the progression of ovarian cancer in chickens.

      PubDate: 2016-06-18T18:51:23Z
  • Table of Contents
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56

      PubDate: 2016-06-18T18:51:23Z
  • Editorial Board
    • Abstract: Publication date: July 2016
      Source:Domestic Animal Endocrinology, Volume 56

      PubDate: 2016-06-18T18:51:23Z
  • A systematic review and meta-analysis of salivary cortisol measurement in
           domestic canines
    • Abstract: Publication date: October 2016
      Source:Domestic Animal Endocrinology, Volume 57
      Author(s): M.L. Cobb, K. Iskandarani, V.M. Chinchilli, N.A. Dreschel
      Salivary cortisol is widely used as an indicator of stress and welfare in canine research. However, much remains unclear about the basic features of this hormone marker in domestic dogs. This systematic review and meta-analysis aimed to determine a reference range for cortisol concentration in the saliva of dogs and examine how canine characteristics, environmental effects and experimental considerations relate to salivary cortisol concentrations. A systematic review of literature databases and conference proceedings from 1992 to 2012 identified 61 peer-reviewed studies using domestic dog salivary cortisol. Researchers were contacted via email, and 31 raw data sets representing a total of 5,153 samples from 1,205 dogs were shared. Meta-analysis provided a cortisol concentration range of 0 to 33.79 μg/dL (mean 0.45 μg/dL, SEM 0.13). Significant effects (P < 0.05) were found for sex and neuter status, age, regular living environment, time in environment before testing, testing environment, owner presence during testing, and collection media. Significant effects were not found for dog breed, body weight, dog type, coat color, assay type, exercise, eating, or use of salivary stimulant. Care should be taken when using cortisol studies for dogs at a group or population level as there is a large amount of intraindividual and interindividual variability and external variables could influence salivary cortisol concentration. This analysis highlights the importance of carefully controlling experimental design to compare samples within and between individual dogs, as well as establishing and using best practices for saliva collection. Caution should be exercised in comparing different studies, as the results could be the reflection of a plethora of factors.

      PubDate: 2016-06-18T18:51:23Z
  • A transcriptional cofactor YAP regulates IFNT expression via transcription
           factor TEAD in bovine conceptuses
    • Abstract: Publication date: October 2016
      Source:Domestic Animal Endocrinology, Volume 57
      Author(s): K. Kusama, R. Bai, T. Sakurai, H. Bai, A. Ideta, Y. Aoyagi, K. Imakawa
      Interferon tau (IFNT) is the pregnancy recognition protein in all ruminants, and its expression is restricted to trophoblast cells. Interferon tau production increases as the conceptus elongates; however, its expression is downregulated soon after the initiation of conceptus attachment to the uterine epithelium. Our previous study identified that among 8 bovine IFNT genes, only 2 forms of IFNTs, IFNT2 and IFN-tau-c1, were expressed by the conceptuses during the periattachment period. To characterize whether Hippo signaling including a transcription cofactor yes-associated protein (YAP) was involved in the IFNT regulation, we examined the expression and effects of YAP and/or TEAD in human choriocarcinoma JEG3 and bovine trophoblast CT-1 cells, and in bovine conceptuses obtained from day 17, 20 or 22 pregnant animals (pregnant day 19.5 = day of conceptus attachment to the endometrium). YAP was expressed in bovine conceptuses and transfection of YAP or TEAD4, a transcription factor partner of YAP, expression plasmid increased the luciferase activity of IFNT2 and IFN-tau-c1 reporter plasmids in JEG3 cells. In the presence of YAP expression plasmid, TEAD2 or TEAD4 expression plasmid further upregulated transcriptional activity of IFNT2 or IFN-tau-c1 constructs, which were substantially reduced in the absence of the TEAD-binding site on IFNT2 or IFN-tau-c1 promoter region in JEG3 cells. In CT-1 cells, treatment with TEAD2, TEAD4, or YAP small-interfering RNA downregulated endogenous IFNT expression. It should be noted that TEAD2 and TEAD4 were predominantly localized in the nuclei of trophectoderm of Day 17 conceptuses, but nuclear localization appeared to be lower in those cells of conceptuses on days 20 and 22 of pregnancy. Moreover, the binding of TEAD4 to the TEAD-binding site of the IFN-tau-c1 promoter region in day 17 conceptuses was less in day 20 and 22 conceptuses. Furthermore, the level of YAP phosphorylation increased in day 20 and 22 conceptuses. These results indicated that although YAP/TEAD had the ability to up-regulate IFNT gene transcription on day 17, IFNT2 or IFN-tau-c1 was down-regulated following changes in the localization of TEAD2 and TEAD4 from the nucleus to the cytoplasm and increases in phosphorylation and degradation of YAP. These data suggest that TEAD relocation and/or YAP degradation following its phosphorylation down-regulates IFNT gene transcription after conceptus attachment to the uterine endometrium.

      PubDate: 2016-06-18T18:51:23Z
  • Transcript levels of genes implicated in steroidogenesis in the testes and
           fat tissue in relation with androstenone accumulation in fat of pubertal
    • Abstract: Publication date: Available online 9 April 2016
      Source:Domestic Animal Endocrinology
      Author(s): A. Robic, K. Feve, J. Riquet, A. Prunier
      The present study was performed to measure mRNA levels of steroidogenic enzymes in testes and fat tissue and determine whether they are related to fat androstenone level. Real time PCR experiments were performed on 26 testes and 12 adipose tissue samples from pubertal boars using 21 genes. The absence of significant correlations between fat androstenone and the transcriptional activity of the SRD5A2 and SRD5A3 genes but the high correlation coefficient with that of the SRD5A1 gene (r = 0.62, P < 0.05) suggest that the enzyme coded by SRD5A1 is mainly responsible for the last step of androstenone synthesis. The testicular transcriptional activities of CYP17, CYP11A1, CYP19A, AKR1C-pig6, SRD5A1, LHCGR, and AR were significantly correlated. Only transcriptional levels of CYP17, CYP11A1, CYP19A, SRD5A1 and AKR1C-pig6 were correlated with the fat concentration of androstenone (0.57 < r < 0.70, P < 0.05) confirming that the amount of androstenone stored in fat is related to the production in testes of androstenone and more generally to all sex steroids. Altogether, our data are in favor of a preponderant role of AKR1C-pig6 instead of HSD17B3 for testicular synthesis of steroids. Concerning fat tissue, our data do not support a significant de novo biosynthesis of steroids in porcine adipose tissues. The presence of transcripts coding for steroid enzymes, especially those of AKR1C-pig6, suggests that steroids can be transformed. None of transcript abundance was related to androstenone accumulation (P > 0.1). Therefore, steroids synthesized elsewhere can be transformed in fat tissue but synthesis of androstenone is unlikely.

      PubDate: 2016-04-09T14:44:46Z
  • Endocrine regulation of gut maturation in early life in pigs
    • Abstract: Publication date: Available online 7 April 2016
      Source:Domestic Animal Endocrinology
      Author(s): T. Thymann
      Following birth the newborn must adapt to the acute challenges of circulatory changes, active respiration, thermoregulation, microbial colonization, and enteral nutrition. Whereas these processes normally occur without clinical complications in neonates born at term, birth at a preterm state of gestation is associated with high morbidity and mortality. In commercial pig production, perinatal mortality is higher than in any other mammalian species. Asphyxia, hypothermia, hypoglycemia, sepsis and gut dysmotility, represent some of the most common findings. The intestine is a particularly sensitive organ after birth, as it must adapt acutely to enteral nutrition and microbial colonization. Likewise, during the weaning phase, the intestine must adapt to new diets types. Both critical phases are associated with high morbidity. This review focuses on the endocrine changes occurring around birth and weaning. There are a number of endocrine adaptations in late gestation and early postnatal life that are under influence of stage of development and environmental factors such as diet. The review discusses general endocrine changes in perinatal life, but specifically focuses on the role of Glucagon-Like Peptide -2 (GLP-2). This gut-derived hormone plays a key role in development and function of the intestine in early life.

      PubDate: 2016-04-09T14:44:46Z
  • Early pregnancy in the mare: old concepts re-visited
    • Abstract: Publication date: Available online 1 April 2016
      Source:Domestic Animal Endocrinology
      Author(s): C. Klein
      “Maternal recognition of pregnancy” (MRP) is commonly used to describe the ongoing embryo-maternal communication during early pregnancy that culminates in prevention of luteolysis and ensures ongoing progestin support. The conceptus-derived pregnancy recognition signal has not yet been identified in the mare. Although equine conceptuses produce substantial amounts of estrogens, there is a lack of evidence that estrogens are the pregnancy recognition signal in mares. Conceptus mobility is integral to MRP and is driven by conceptus-derived prostaglandin production. Cessation of conceptus mobility, referred to as fixation, is caused by increases in conceptus size and uterine tone, and reduction in sialic acid content of the embryonic capsule. Gene expression profiling of equine pre-implantation conceptuses revealed expression of neuraminidase 2 (NEU2), an enzyme that cleaves sialic acid from polysaccharide chains. Furthermore, secretion of NEU2 by conceptuses in vitro was functionally active; it appears therefore, that the conceptus itself regulates sialic acid content through expression of NEU2. Based on gene expression profiling, equine conceptuses express increasing amounts of fibrinogen during early development. Western blot analysis confirmed secretion of fibrinogen into culture medium when conceptuses were cultured in vitro and with immunohistochemistry, the acellular glycoprotein capsule of the conceptus had particularly intense staining for fibrinogen. Therefore, we hypothesize that conceptus-derived fibrinogen interacts with endometrial integrins to promote cessation of conceptus mobility and fixation. Indeed, next generation sequencing analysis of conceptus and endometrial samples 16 d after ovulation revealed the integrin signaling pathway is significantly enriched in both sample types. Real-time RT-PCR confirmed ITGAVB1 as the most abundant integrin receptor in endometrium; fibrinogen has the highest affinity for ITGAVB1 amongst integrins receptors to which it binds. Lastly, the equine conceptus expresses increasing quantities of relaxin during pre-implantation development, with the endometrium expressing relaxin receptors. In the pig, mouse and human, relaxin is produced by the corpus luteum and is known to promote angiogenesis during early pregnancy. In summary, substantial advances in understanding MRP in the horse are underway.

      PubDate: 2016-04-06T14:37:11Z
  • Stress, cortisol and obesity: a role for cortisol responsiveness in
           identifying individuals prone to obesity
    • Abstract: Publication date: Available online 31 March 2016
      Source:Domestic Animal Endocrinology
      Author(s): S.D. Hewagalamulage, T.K. Lee, I.J. Clarke, B.A. Henry
      There is a strong inter-relationship between activation of the hypothalamo-pituitary adrenal axis and energy homeostasis. Patients with abdominal obesity have elevated cortisol levels. Furthermore, stress and glucocorticoids act to control both food intake and energy expenditure. In particular, glucocorticoids are known to increase the consumption of foods enriched in fat and sugar. It is well known that, in all species, the cortisol response to stress or adrenocorticotropin is highly variable. It has now emerged, that cortisol responsiveness is an important determinant in the metabolic sequelae to stress. Sheep that are characterised as high cortisol responders (HR) have greater propensity to weight gain and obesity than low cortisol responders (LR). This difference in susceptibility to become obese is associated with a distinct metabolic, neuroendocrine and behavioral phenotype. In women and ewes, HR individuals eat more in response to stress than LR. Furthermore, HR sheep have impaired melanocortin signalling and reduced skeletal muscle thermogenesis. HR sheep exhibit reactive coping strategies, whereas LR exhibit proactive coping strategies. This complex set of traits leads to increased food intake and reduced energy expenditure in HR and thus predisposition to obesity. We predict that cortisol responsiveness may be used as a marker to identify individuals that are at risk of weight gain and subsequent obesity.

      PubDate: 2016-04-01T21:46:17Z
  • The role of mitochondrial DNA copy number, variants and haplotypes in farm
           animal developmental outcome
    • Abstract: Publication date: Available online 31 March 2016
      Source:Domestic Animal Endocrinology
      Author(s): Tesha Tsai, Justin C. St. John
      The vast majority of cellular energy is generated through the process of oxidative phosphorylation, which takes place in the electron transfer chain in the mitochondria. The ETC is encoded by two genomes, the chromosomal and the mitochondrial (mtDNA) genomes. MtDNA is associated with a number of traits, which include tolerance to heat, growth and physical performance, meat and milk quality and fertility. Mitochondrial genomes can be clustered into groups known as mtDNA haplotypes. MtDNA haplotypes are a potential genetic source for manipulating phenotypes in farm animals. The use of assisted reproductive technologies, such as nuclear transfer, allow favourable chromosomal genetic traits to be mixed and matched with sought after mtDNA haplotype traits. As a result super breeds can be generated.

      PubDate: 2016-04-01T21:46:17Z
  • Influence of blanketing and season on vitamin D and parathyroid hormone,
    • Abstract: Publication date: Available online 19 March 2016
      Source:Domestic Animal Endocrinology
      Author(s): S. Azarpeykan, K.E. Dittmer, E.K. Gee, J.C. Marshall, J. Wallace, P. Elder, E. Acke, K.G. Thompson
      The aims of the study were to determine effect of season and blanketing on vitamin D synthesis in horses, and examine the interaction between vitamin D and other analytes involved in calcium homeostasis. Twenty-one healthy horses at pasture were included; 5 were covered with standard horse blankets including neck rugs. Blood samples were collected for 13 mo and analyzed for 25-hydroxyvitamin D2 (25OHD2), and 25-hydroxyvitamin D3 (25OHD3), 1,25-dihydroxyvitamin D (1,25(OH)2D), ionized calcium (iCa), total calcium (tCa), phosphorus (P), total magnesium (tMg) and parathyroid hormone (PTH). Grass and hay samples were collected and analyzed for vitamin D, calcium, phosphorus and magnesium. Climate data were also collected. The serum concentration of 25OHD3 in horses either undetectable or below the detection limit of the assay, and the main form of 25OHD was 25OHD2. No differences in serum 25OHD2, 1,25(OH)2D, iCa, tCa, P, tMg and PTH (P ≥ 0.05) concentrations were seen between the 2 groups. Associations were seen between iCa and PTH (P < 0.05), iCa and tMg (P < 0.05) and dietary vitamin D and 25OHD2 (P < 0.05). A strong seasonal trend was seen in serum 25OHD2 (P < 0.0001) which was higher during spring and summer when the amount of sunshine and UV radiation was higher. Parathyroid hormone and 1,25(OH)2D showed opposing trends with PTH higher in winter while 1,25(OH)2D was higher in summer. The results suggest that dietary vitamin D maybe necessary for horses to fulfill their vitamin D requirements, however further research is required to determine the contribution of vitamin D3 synthesis in the skin to the vitamin D status of the horse.

      PubDate: 2016-03-23T19:29:13Z
  • Characteristics and functions of a minor FSH surge near the end of an
           interovulatory interval in Bos taurus heifers
    • Abstract: Publication date: Available online 17 March 2016
      Source:Domestic Animal Endocrinology
      Author(s): O.J. Ginther, J.M. Baldrighi, M.A.R. Siddiqui, C.A. Wolf
      The apparent function of a minor FSH surge based on temporality with follicular events was studied in 10 heifers with 2 follicular waves per interovulatory interval. Individual follicles were tracked from their emergence at 2 mm until their outcome was known and a blood sample was collected for FSH and LH assay every 12 h from Day −14 (Day 0 = ovulation) to Day 4. A minor FSH surge occurred in each heifer (peak, Day −4.6 ± 0.2). Concentration of LH increased (P < 0.05) during the FSH increase of the minor surge but did not decrease during the FSH decrease. A minor follicular wave with 8.2 ± 2.0 follicles occurred in 6 of 10 heifers. The maximal diameter (mean, 3.4 ± 0.9 mm) of 77% of the minor-wave follicles occurred in synchrony on Day −4.4 ± 0.4. Most (59%) of minor wave follicles regressed before ovulation and 41% decreased and then increased in diameter (recovered) on Day −1.9 ± 0.3 to become part of the subsequent wave 1. A mean of 3.7 ± 0.9 regressing subordinate follicles from wave 2 recovered on the day before or at the peak of the minor FSH surge. The growth rate of the preovulatory follicle decreased (P < 0.02) for 3 d before the peak of the minor FSH surge and then increased (P < 0.03). Concentration of LH increased slightly but significantly temporally with the resurgence in growth rate of the preovulatory follicle. A minor LH surge peaked (P < 0.0002) on Day 3 at the expected deviation in growth rates between the future dominant and subordinate follicles. Results indicated on a temporal basis that the recovery of some regressing subordinate follicles of wave 2 was attributable to the minor FSH surge. The hypothesis was supported that some regressing follicles from the minor follicular wave recover to become part of wave 1.

      PubDate: 2016-03-19T18:43:07Z
  • Assessment of caprine corpora lutea growth, progesterone concentration and
           eNOS expression: Effect of a compensatory gain model
    • Abstract: Publication date: Available online 8 March 2016
      Source:Domestic Animal Endocrinology
      Author(s): J. Thammasiri, C. Navanukraw, S. Uriyapongson, V. Khanthusaeng, K. Lertchunhakiat, S. Boonkong
      The experiment was conducted to evaluate corpus luteum (CL) growth, progesterone (P4) concentration and endothelial nitric oxide synthase (eNOS) expression in nutrient stair-step fed goats. Female goats (n = 32) that exhibited at least two, normal, consecutive estrous cycles were randomly assigned to either the control or stair-step fed group. In the control group, goats were fed ad libitum (100% of nutrient requirement for goats). The goats in the stair-step group were fed 70% of the control consumption for the first 42 d and 130% for the later 42 d during four consecutive estrous cycles (84 d). Blood and luteal samples were collected on days 3, 8, 13, 18 of the estrous cycle to determine concentration of glucose, insulin, P4, luteal growth, and eNOS expression. Luteal growth was determined using fresh CL weight, DNA content, DNA and protein concentrations, and cell proliferation (labeling index of Ki67). During realimentation phase at 4 h, glucose and insulin concentrations were greater (P < 0.05) in stair-step fed goat than control goats. Fresh CL weight, DNA content, protein concentrations and labeling index of Ki67 on day 8 of the estrous cycle in the stair-step group were greater (P < 0.05) than that of the control group. Protein for eNOS was located in the capillaries of CL throughout of the estrous cycle in both groups. Greater serum P4 concentrations and eNOS protein (P < 0.05) were observed in the stair-step fed goats on day 3 (1.83 ng/mL and 6.79%) compared to the control goats (0.98 ng/mL and 6.02%), and on day 8 (5.15 ng/mL and 7.88%) compared to the control goats (4.54 ng/mL and 7.07%). These data demonstrate that luteal growth, progesterone concentration, and eNOS protein were partially affected by nutrient compensatory gain in goats.

      PubDate: 2016-03-10T17:27:29Z
  • Dynamics of L cells along the crypt-villous axis in the chicken ileum
    • Abstract: Publication date: Available online 3 March 2016
      Source:Domestic Animal Endocrinology
      Author(s): K. Nishimura, K. Hiramatsu, T. Watanabe
      The dynamics of L cells along the crypt-villous axis were investigated in the ileum of male White Leghorn chicks (7 d of age, n=5). Immunohistochemistry was used to detect the expression of glucagon-like peptide (GLP)-1 and an in situ hybridization technique to detect proglucagon mRNA. Immunocytochemistry using colloidal gold was also applied to quantitatively evaluate the GLP-1 content. The cells expressing a proglucagon mRNA signal were distributed mainly in the crypts and the bottom of the villi, but were never found in the upper part of the villi. Most of the cells expressing a proglucagon mRNA signal (97%) were immunoreactive for GLP-1 antiserum. In contrast, GLP-1 immunoreactive cells were distributed from the crypts to the middle part of the villi, and only 55% of them expressed a proglucagon mRNA signal. Quantitative evaluation by immunocytochemistry of GLP-1 using colloidal gold revealed that the GLP-1 content was significantly lower in L cells located in the villous epithelium than that of L cells located in the crypts (p<0.01). These findings indicate that L cells in the chicken ileum mature and complete GLP-1 production in the crypts. L cells in the villous epithelium secrete GLP-1, but do not synthesize this peptide.

      PubDate: 2016-03-05T16:53:21Z
  • Cattle temperament influences metabolism: Metabolic response to glucose
           tolerance and insulin sensitivity tests in beef steers†,‡
    • Abstract: Publication date: Available online 4 March 2016
      Source:Domestic Animal Endocrinology
      Author(s): N.C. Burdick Sanchez, J.A. Carroll, P.R. Broadway, H.D. Hughes, S.L. Roberts, J.T. Richeson, T.B. Schmidt, R.C. Vann
      Cattle temperament, defined as the reactivity of cattle to humans or novel environments, can greatly influence several physiological systems in the body, including immunity, stress, and most recently discovered, metabolism. Greater circulating concentrations of non-esterified fatty acids (NEFAs) found in temperamental cattle suggests that temperamental cattle are metabolically different than calm cattle. Further, elevated NEFA concentrations have been reported to influence insulin sensitivity. Therefore, the objective of this study was to determine whether cattle temperament would influence the metabolic response to a glucose tolerance test (GTT) and insulin sensitivity test (IST). Angus-cross steers (16 Calm and 15 Temperamental; 216 ± 6 kg BW) were selected based on Temperament Score measured at weaning. On day 1, steers were moved into indoor stanchions to allow measurement of individual ad libitum feed intake. On day 6, steers were fitted with indwelling rectal temperature probes and jugular catheters. At 0900 h on day 7, steers received the GTT (0.5 mL/kg BW of a 50% dextrose solution) and at 1400 h on day 7, steers received the IST (2.5 IU bovine insulin/kg BW). Blood samples were collected and serum isolated at -60, -45, -30, -15, 0, 10, 20, 30, 45, 60, 90, 120, and 150 min relative to each challenge. Serum was stored at -80oC until analyzed for cortisol, glucose, NEFA, and blood urea nitrogen (BUN) concentrations. All variables changed over time (P < 0.01). For the duration of the study, Temperamental steers maintained greater (P < 0.01) serum NEFA and less (P ≤ 0.01) serum BUN and insulin sensitivity (calculated using RQUICKI) compared to Calm steers. During the GTT, Temperamental steers had greater (P < 0.01) serum glucose, yet decreased (P = 0.03) serum insulin, and (P < 0.01) serum insulin: serum glucose compared to Calm cattle. During the IST, Temperamental steers had greater (P < 0.01) serum insulin and a greater (P < 0.01) serum insulin: serum glucose as compared to Calm steers. These data demonstrate that differences exist in the manner in which Temperamental steers respond to glucose and insulin, potentially a result of elevated serum NEFA concentrations, which may result in changes in utilization and redistribution of energy in Temperamental versus Calm cattle.

      PubDate: 2016-03-05T16:53:21Z
  • Molecular characterization of kisspeptin gene and effect of
           nanoencapsulted kisspeptin-10 on reproductive maturation in Catla catla
    • Abstract: Publication date: Available online 3 March 2016
      Source:Domestic Animal Endocrinology
      Author(s): M.A. Rather, I.A. Bhat, G.B. Pathakota, A. Chaudhari, J.K. Sundaray, R. Sharma
      Kisspeptin, a member of the RF-amide related peptide family, has emerged recently as an essential gatekeeper of various reproductive processes via its ability to activate kisspeptin receptors at puberty. In this study, the kiss1 gene and its receptor kiss1rb were cloned and characterized from the brain of Catla catla. Further, the effects of kissppetin-10 (K-10) and chitosan encapsulated K-10 nanoparticles (CK-10) on gene expression were assessed. The full-length cDNA sequence of kiss1 is 754 bp with an open reading frame (ORF) of 351 bp that encodes a putative protein of 116 amino acids. The kiss1rb cDNA is 1280 bp long and contains a 5'-UTR (untranslated region) of 30 bp, 3'-UTR of 149 bp, and an ORF(open reading frame) of 1101 bp. The expression patterns of kiss1 and kiss1rb mRNA in basal tissues revealed that they are mainly expressed in the brain, pituitary gland and gonads. CK-10 nanoparticles with a particle size of 125 nm and a zeta potential of 36.45 mV were synthesized and compared with K-10. Chitosan nanoparticles showed 60% entrapment efficiency for K-10. The mRNA expression of reproductive genes (GnRH, LH and FSH) in fish injected with K-10 declined after 6 h while those injected with CK-10 showed controlled and a sustained surge of mRNA expression of these genes with a peak at 12 h. Histological examination of ovaries indicated a pronounced effect of CK-10 on maturation and gonadal development. The study reports that this sustained-release-delivery-system will help in increasing the half-life of K-10 and other therapeutic protein drugs in the biological system. Besides, the nanoformulation developed in the current study may be useful for developing therapies against various reproductive dysfunctions in vertebrates.

      PubDate: 2016-03-05T16:53:21Z
  • Endocrine, morphometric and ultrasonographic characterization of neck
           adiposity in Andalusian horses
    • Abstract: Publication date: Available online 26 February 2016
      Source:Domestic Animal Endocrinology
      Author(s): T. Martin-Gimenez, I. de Blas, E. Aguilera-Tejero, E. Diez de Castro, C.N. Aguirre-Pascasio
      Equine Metabolic Syndrome (EMS) can be diagnosed by hormonal measurements; however, it would be important to find simpler measurements that allow easy identification of affected or at risk individuals. In horses, the dorsal neck region is one of the most frequent anatomical sites for fat deposition and neck obesity has been linked to EMS. The aim of this study was to evaluate the association of hormonal markers of obesity (leptin) and insulin resistance (insulin) with morphometric and ultrasonographic neck measurements in Andalusian horses. Plasma leptin and insulin concentrations were measured by radioimmunoassay in 127 Andalusian horses. Neck circumferences (NC) were measured at three equidistant locations at 25%, 50% and 75% of neck length (NC-25%, NC-50%, NC-75%). At the same three locations, subcutaneous fat thickness (SFT-25%, SFT-50%, SFT-75%) was measured ultrasonographically. In the population under study, a tendency to adiposity was confirmed by the elevated plasma leptin levels (7.47 ± 5.03 ng/mL). However, plasma insulin concentrations (4.05 ± 3.74 μIU/mL) were within normal range in most horses. Our results indicate that NC showed significant sexual dimorphism and did not correlate well with hormonal measurements. Ultrasonographic assessment of fat thickness at the base of the neck (SFT-75%) was significantly correlated with both plasma leptin and insulin, and did not show differences between males and females. Thus, in the search for a single objective parameter which can be used in large populations SFT-75% is a potential candidate and may be a meaningful parameter to predict EMS.

      PubDate: 2016-02-29T16:06:26Z
  • Expression of nerve growth factor and its receptors in the uterus of
           rabbits: functional involvement in prostaglandin synthesis
    • Abstract: Publication date: Available online 19 February 2016
      Source:Domestic Animal Endocrinology
      Author(s): M. Maranesi, F. Parillo, L. Leonardi, P.G. Rebollar, B. Alonso, L. Petrucci, A. Gobbetti, C. Boiti, J. Arruda-Alencar, A. Moura, M. Zerani
      The aim of the present study was to evaluate: 1) the presence of nerve growth factor (NGF) and the neurotrophic tyrosine kinase receptor 1 (NTRK1) and nerve growth factor receptor (NGFR) in the rabbit uterus; and 2) the in vitro effects of NGF on PGF2α and PGE2 synthesis and on the PGE2-9-ketoreductase (PGE2-9-K) activity by the rabbit uterus. NGF, NTRK1, and NGFR were immunolocalized in the luminal and glandular epithelium and stroma cells of the endometrium. RT-PCR indicated the presence of mRNA for NGF, NTRK1, and NGFR in the uterus. NGF increased (P < 0.01) in vitro secretions of PGF2α and PGE2 but co-incubation with either NTRK1 or oxide nitric synthase (NOS) inhibitors reduced (P < 0.01) PGF2α production and blocked (P < 0.01) PGE2 secretion. Prostaglandins releases were lower (P < 0.01) than control when uterine samples were treated with NGF plus cyclooxygenase (COX) inhibitor. However, addition of NGFR inhibitor reduced (P < 0.01) PGF2α secretion less efficiently than NTRK1 or NOS inhibitors, but had no effect on PGE2 yield. NGF increased (P < 0.01) the activity of PGE2-9-K, while co-incubation with NTRK1 or NOS inhibitors abolished (P < 0.01) this increase in PGE2-9-K activity. However, co-treatment with either COX or NGFR inhibitors had no effect on PGE2-9-K activity. This is the first study to document the distribution of NGF/NTRK1 and NGFR systems and their effects on PG synthesis in the rabbit uterus. NGF/NTRK1 increases PGF2α and PGE2 productions by up-regulating NOS and PGE2-9-K activities, whereas NGF/NGFR augments only PGF2α secretion, through an intracellular mechanism that is still unknown.

      PubDate: 2016-02-20T13:06:37Z
  • Increased expression of pentraxin 3 after in vivo and in vitro stimulation
           with gonadotropins in porcine oocyte-cumulus complexes and granulosa cells
    • Abstract: Publication date: Available online 19 February 2016
      Source:Domestic Animal Endocrinology
      Author(s): E. Nagyova, J. Kalous, L. Nemcova
      It has been previously shown that multimeric pentraxin 3 (PTX3) is a key component of the cumulus oophorus extracellular matrix (ECM) in mice. In response to the ovulatory LH surge, the cumulus cells assemble a unique ECM that envelopes the oocyte and cumulus cell complex. Importantly, cumuli from PTX3-/- mice were defective in their ECM organization and their fertility was impaired. It has been demonstrated that tumor necrosis factor alpha-induced protein 6 (TNFAIP6) catalyzes the formation of heavy chains of (inter-alpha-trypsin inhibitor) -hyaluronan complexes and these are then cross-linked via PTX3. This process is tightly regulated, and requires the proteins to meet/interact in the correct order. Finally, in this way the above-listed proteins form the cumulus oophorus ECM. We investigated whether PTX3 is expressed in the porcine preovulatory follicle. Porcine oocyte-cumulus complexes (OCC) and mural granulosa cells (MGC) from gilts were obtained either after stimulation in vivo with eCG/ hCG (4, 8, 16, 24 and 32 h) or culture in vitro (4, 24 and 44 h) in FSH/LH-supplemented medium. The methods performed were real-time RT-PCR, Western blot analysis, and immunostaining. The expression of PTX3 transcripts was significantly increased 24 h after either in vivo hCG stimulation or in vitro FSH/LH treatment in both OCC and MGC. Western blot analysis with PTX3 antibody revealed that not only matrix extracts from in vivo stimulated gilts contain high levels of PTX3 protein, but also matrix extracts of FSH/LH-stimulated OCC cultured in medium supplemented either with follicular fluid or with porcine serum. The localization of PTX3 in the cumulus oocyte complex was confirmed by immunostaining. In conclusion, PTX3 is produced by porcine OCC and mural granulosa cells both in vivo and in vitro with gonadotropin stimuli inducing cumulus expansion.

      PubDate: 2016-02-20T13:06:37Z
  • Expression analysis of bone morphogenetic protein 4 between fat and lean
           birds in adipose tissue and serum
    • Abstract: Publication date: Available online 30 January 2016
      Source:Domestic Animal Endocrinology
      Author(s): B.H. Cheng, L. Leng, M.Q. Wu, Q. Zhang, X.Y. Zhang, S.S. Xu, Z.P. Cao, Y.M. Li, P. Luan, H. Li
      The objectives of the current study were to characterize the tissue expression of chicken (Gallus gallus) bone morphogenetic protein 4 (BMP4) and compare differences in its expression in abdominal fat tissue and serum between fat and lean birds, and to determine a potential relationship between the expression of BMP4 and abdominal fat tissue growth and development. The results showed that chicken BMP4 mRNA and protein were expressed in various tissues, and the expression level of BMP4 transcript and protein was relatively higher in adipose tissues. In addition, the mRNA and protein expression levels of BMP4 in abdominal fat tissue of fat males were lower than that of lean males at 1, 2, 5 and 7 wk of age (P < 0.05). Furthermore, the serum BMP4 content of fat males was lower than that of lean males at 7 wk of age (P < 0.05). Bone morphogenetic protein 4 mRNA expression levels were significantly higher in preadipocytes than in mature adipocytes (P < 0.05), and the expression level decreased during differentiation in vitro (P < 0.05). These results suggested that chicken BMP4 might affect abdominal fat deposition through differences in its expression level. The results of this study will provide basic molecular information for studying the role of BMP4 in the regulation of adipogenesis in avian species.

      PubDate: 2016-02-01T12:11:52Z
  • Effects of steroid treatment on growth, nutrient partitioning, and
           expression of genes related to growth and nutrient metabolism in adult
           triploid rainbow trout (Oncorhynchus mykiss)
    • Abstract: Publication date: Available online 25 January 2016
      Source:Domestic Animal Endocrinology
      Author(s): B.M. Cleveland, G.M. Weber
      The contribution of sex steroids to nutrient partitioning and energy balance during gonad development was studied in rainbow trout. Specifically, 19-mo old triploid (3N) female rainbow trout were fed treatment diets supplemented with estradiol-17β (E2), testosterone (T), or dihydrotestosterone (DHT) at 30 mg steroid/kg diet for a 1-mo period. Growth performance, nutrient partitioning, and expression of genes central to growth and nutrient metabolism were compared to 3N and age-matched diploid (2N) female fish consuming a control diet not supplemented with steroids. Only 2N fish exhibited active gonad development, with gonad weights (GSI) increasing from 3.7% to 5.5% of body weight throughout the study while GSI in 3N fish remained at 0.03%. Triploid fish consuming DHT exhibited faster specific growth rates than 3N controls (P < 0.05). Consumption of E2 in 3N fish reduced fillet growth and caused lower fillet yield compared to all other treatment groups (P < 0.05). In contrast, viscera fat gain was not affected by steroid consumption (P > 0.05). Gene transcripts associated with physiological pathways were identified in maturing 2N and E2-treated 3N fish that differed in abundance from 3N control fish (P < 0.05). In liver these mechanisms included the growth hormone/insulin-like growth factor (IGF) axis (igf1, igf2), IGF binding proteins (igfbp1b1, igfbp2b1, igfbp5b1, igfbp6b1), and genes associated with lipid binding and transport (fabp3, fabp4, lpl, cd36), fatty acid oxidation (cpt1a), and the pparg transcription factor. In muscle these mechanisms included reductions in myogenic gene expression (fst, myog) and the proteolysis-related gene, ctsl, suggesting an E2-induced reduction in the capacity for muscle growth. These findings suggest that increased E2 signaling in the sexually maturing female rainbow trout alters physiological pathways in liver, particularly those related to IGF signaling and lipid metabolism, to partition nutrients away from muscle growth towards support of maturation-related processes. In contrast, the mobilization of viscera lipid stores appear to be mediated less by E2 and more by energy demands associated with gonad development. These findings improve understanding of how steroids regulate nutrient metabolism to meet the high energy demands associated with gonad development during sexual maturation.

      PubDate: 2016-01-28T12:02:36Z
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