Domestic animal endocrinology最新文献

{"title":"The impact of environmental and nutritional stresses on milk fat synthesis in dairy cows","authors":"A. Razzaghi ,&nbsp;M.H. Ghaffari ,&nbsp;D.E. Rico","doi":"10.1016/j.domaniend.2022.106784","DOIUrl":"10.1016/j.domaniend.2022.106784","url":null,"abstract":"<div><p>Stress reduces milk and milk components synthesis and increases maintenance requirements of cows. The major stress-related alterations involve enhanced secretion of glucocorticoids and increased sympathetic nervous system activity, which results in biochemical and physiologic changes. In dairy cows exposed to social (ie housing conditions, overstocking, regrouping, feed delivery), physiological (ie initiation of lactation and parturition), or physical (ie heat or cold stress) stressors, responses involve alterations in energy balance and nutrient partitioning. The capacity of the animal to synthesize milk fat largely depends on the availability of substrates for lipid synthesis from the diet, ruminal fermentation or adipose tissue stores, all of which can be altered under stress conditions. Indeed, milk fat concentration is particularly responsive to diet and environment modifications, where a wide range of nutritional and non-nutritional factors influence milk fat output. Milk fat synthesis is an energy demanding process, and extremely sensitive to stress factors during lactation and the involvement of multiple organs. Recent studies examining social, physical, and physiological stressors have provided important insights into how differences in milk yield and milk components may be associated with biological responses to stress factors in dairy cows. This review focuses primarily on the role of stress sources and indicators to which the dairy cow is exposed in regulating milk fat synthesis. We will review the role of nutritional and non-nutritional factors on milk fat synthesis in dairy cows under stress conditions.</p></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"83 ","pages":"Article 106784"},"PeriodicalIF":2.1,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9529758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short Communication: Identification of equine corticotropin-like intermediate lobe peptide (CLIP) binding to an adrenocortipcotrophic hormone (ACTH) assay capture antibody","authors":"E.J. Knowles ,&nbsp;C. Hyde ,&nbsp;P.A. Harris ,&nbsp;J. Elliott ,&nbsp;N.J. Menzies-Gow","doi":"10.1016/j.domaniend.2023.106785","DOIUrl":"10.1016/j.domaniend.2023.106785","url":null,"abstract":"<div><p>A chemiluminescent immunoassay is commonly employed to measure adrenocorticotrophic hormone (ACTH) concentrations to assist pituitary <em>pars intermedia</em> dysfunction diagnosis. In a previous study, seasonally-dependent assay cross-reactivity to endogenous equine corticotropin-like intermediate lobe peptide (CLIP, ACTH 18–39) was suspected. The present study aimed to demonstrate binding of endogenous equine CLIP to the capture antibody of the ACTH chemiluminescent immunoassay. Liquid chromatography – mass spectrometry (LCMS) methods were optimised to identify selected ions from synthetic human ACTH, α-melanocyte stimulating hormone (α-MSH, ACTH 1–17) and CLIP. Synthetic ACTH and CLIP bound to the capture antibody of the chemiluminescent ACTH assay, but α-MSH did not. Equine endogenous CLIP was detected by LCMS in pony plasma taken in the autumn and could be eluted from the capture antibody of the ACTH chemiluminescent immunoassay. Further research is required to enable quantification of CLIP. Equine CLIP may alter measured ACTH concentrations <em>in vivo.</em></p></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"83 ","pages":"Article 106785"},"PeriodicalIF":2.1,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9517773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of different doses of estradiol benzoate used in a cervical relaxation protocol on the success of non-surgical embryo recovery and luteal function in superovulated ewes","authors":"J.H. Dias ,&nbsp;J.D. Gonçalves ,&nbsp;A.M. Arrais ,&nbsp;J.M.G. Souza-Fabjan ,&nbsp;R. Bastos ,&nbsp;R.I.T.P. Batista ,&nbsp;L.G.B. Siqueira ,&nbsp;M.E.F. Oliveira ,&nbsp;J.F. Fonseca","doi":"10.1016/j.domaniend.2022.106751","DOIUrl":"10.1016/j.domaniend.2022.106751","url":null,"abstract":"<div><p>This study investigated the effectiveness of different doses of estradiol benzoate (EB) to promote cervical relaxation and their effects on luteal function and outcomes of non-surgical embryo recovery (NSER) in sheep. Multiparous (MULT) and nulliparous (NULL) crossbred Lacaune X Santa Inês ewes were superovulated and naturally bred. Seven days after progesterone withdrawal, females were randomly assigned to one of three distinct cervical relaxation protocols, consisting of i.m. treatment with 37.5 µg d-cloprostenol and different doses of EB: 0.0 mg (0.0EB group; n = 3 NULL and 14 MULT); 0.5 mg (0.5EB group; n = 4 NULL and 12 MULT) or 1.0 mg (1.0EB group, n = 6 NULL and 11 MULT) 16 h before NSER. All ewes received 50 IU of oxytocin 20 min before NSER (D17). Blood samples were collected and ultrasound exams (B-mode and color Doppler) were performed at two timepoints: immediately before d-cloprostenol and EB treatments and prior to NSER. Estrous behavior, corpora lutea count and NSER success outcomes were not affected by EB treatments nor parity (<em>P</em> &gt; 0.05). Embryo recovery rate was greater for ewes in the 0.5EB group and in the NULL ewes (<em>P</em> &lt; 0.05). Ovarian biometrics differed between the two evaluation timepoints in all groups (<em>P</em> &lt; 0.05). Plasma estradiol increased over time, reaching a significant greater level in 1.0EB ewes compared to controls on D17 (<em>P</em> &lt; 0.05), whereas progesterone concentrations decreased over time in all groups (<em>P</em> &gt; 0.05). In conclusion, treatments did not affect NSER success but they did affect luteal function by altering P4 and E2 concentrations. Therefore, the NSER technique can be successfully performed in ewes with or without prior treatment with EB.</p></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"82 ","pages":"Article 106751"},"PeriodicalIF":2.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40555051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of a single dose of long-acting FSH on testicular blood flow, testicular echotexture, and circulating testosterone, estradiol, and nitric oxide in rams during the non-breeding season","authors":"H. Samir ,&nbsp;A.S. El-Shalofy,&nbsp;H.R. El-Sherbiny","doi":"10.1016/j.domaniend.2022.106765","DOIUrl":"10.1016/j.domaniend.2022.106765","url":null,"abstract":"<div><p>The present study investigated the effect of a single administration of long-acting follicle simulation hormone (FSH) on testicular blood perfusion as measured by pulsed-wave Doppler ultrasonography, testicular echotexture, and circulating testosterone (T), estradiol (E2), and nitric oxide (NO) in the plasma of rams in the non-breeding season. Twelve Ossimi rams were subjected to either a single administration of long-acting FSH subcutaneously (FSH group; n = 6) or the vehicle (control group; n = 6). Assessment of testicular hemodynamics at the level of the supratesticular artery was performed just before administration (0 h), and at 4, 24, 48, 72, 96, and 168 h after FSH or the vehicle administrations. Testicular volume (TV), and echotexture of testicular parenchyma including pixel intensity and heterogeneity were derived by the computer analysis software. Concentrations of T, E2, and NO were measured using commercial kits. Results revealed significant decreases (<em>P</em> ˂ 0.05) in the values of Doppler indices (resistive index: RI and pulsatility index: PI), especially at 48 h after administration of FSH (RI: 0.42 ± 0.02, PI: 0.56 ± 0.04) compared to their values in the control group (RI: 0.54 ± 0.03, PI: 0.77 ± 0.04). FSH administration induced significant decreases (<em>P</em> ˂ 0.05) in the pixel intensity of testicular parenchyma. Testicular volume and T concentrations were not significantly changed (<em>P</em> ˃ 0.05). Concentrations of E2 increased significantly (<em>P</em> ˂ 0.05) at 48 h and 72 h after FSH administration. (30.07 ± 5.23 pg/ml, 29.93 ± 1.44 pg/ml, respectively) compared to their values before FSH administration (14.63 ± 1.37 pg/ml). Concentrations of NO increased significantly (<em>P</em> ˂ 0.05) in the FSH group between 4 h to 48 h compared to the values in the control one. In conclusion, a single administration of long-acting FSH enhanced testicular blood perfusion as measured by pulsed Doppler ultrasonography in rams during the non-breeding season. Concurrently, significant increases in the concentrations of E2 and NO were found.</p></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"82 ","pages":"Article 106765"},"PeriodicalIF":2.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33522517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular regulation, breed differences and genes involved in stress control in farm animals","authors":"S.O. Durosaro ,&nbsp;O.S. Iyasere ,&nbsp;B.M. Ilori ,&nbsp;V.J. Oyeniran ,&nbsp;M.O. Ozoje","doi":"10.1016/j.domaniend.2022.106769","DOIUrl":"10.1016/j.domaniend.2022.106769","url":null,"abstract":"<div><p>Stress is a state of disturbed homeostasis evoking a multiplicity of somatic and mental adaptive reactions resulting from any of the 5 freedoms of animals being violated. Many environmental forces disrupt homeostasis in farm animals, such as extreme temperatures, poor nutrition, noise, hunger, and thirst. During stressful situations, neuronal circuits in the limbic system and prefrontal cortex are activated, which lead to the release of adrenalin and noradrenalin. The hormones released during stress are needed for adaptation to acute stress and are regulated by many genes. This review examined molecular regulation, breed differences, and genes involved in stress control in farm animals. Major molecular regulation of stress, such as oxidative, cytosolic heat shock, unfolded protein, and hypoxic responses, were discussed. The responses of various poultry, ruminant, and pig breeds to different stress types were also discussed. Gene expressions and polymorphisms in the neuroendocrine and neurotransmitter pathways were also elucidated. The information obtained from this review will help farmers mitigate stress in farm animals through appropriate breed and gene-assisted selection. Also, information obtained from this review will add to the field of stress genetics since stress is a serious welfare issue in farm animals.</p></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"82 ","pages":"Article 106769"},"PeriodicalIF":2.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33541418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expressions of ghrelin and GHSR-1a in the corpus luteum and the stimulatory effect of ghrelin on luteal function of pregnant sows","authors":"Wenlong Zhang,&nbsp;Jiang Peng,&nbsp;Sitian Yang,&nbsp;Yupei Huang,&nbsp;Dewen Tong","doi":"10.1016/j.domaniend.2022.106763","DOIUrl":"10.1016/j.domaniend.2022.106763","url":null,"abstract":"<div><p>Studies have shown that ghrelin played direct actions in ovarian function, but the direct role of ghrelin in corpus luteum (CL) of pregnant sows has remained obscure. The study aimed to examine the expressions of ghrelin and its functional receptor (GHSR-1a) in the CL of sows during pregnancy, and evaluate the role of ghrelin in CL function of pregnant sows. Immunohistochemistry analysis showed that ghrelin and GHSR-1a are both predominantly localized in the luteal cells of pregnant sows CL. Strong immunoreactivity for ghrelin and GHSR-1a is detected at days 20 (early) and 50 (middle), but weak immunoreactivity is observed at days 90 (late) post mating. Similarly, there is a significant effect of pregnant phase on the expression (mRNA and protein) of ghrelin and GHSR-1a in the CL, with higher levels at days 20 (early) and 50 (middle), and lower values at 90 (late) post mating. <em>In vitro</em>, treatments of luteal cells with ghrelin (from 0.01 to 10 ng/mL) are promoted cell viability and P4 secretion in a dose-dependent manner. Ghrelin is also accelerated the LH-induced P4 secretion in luteal cells. Moreover, ghrelin is induced the release and mRNA expression of LH, and increased the release of prostaglandin (PG)E₂, but reduced the secretion of PGF_2α in luteal cells. In conclusion, the presences of ghrelin and GHSR-1a in the porcine CL during pregnancy, and the stimulatory effect of ghrelin on luteal cells suggest positive regulation by ghrelin in CL function of pregnant sows.</p></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"82 ","pages":"Article 106763"},"PeriodicalIF":2.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40375625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coat color affects cortisol and serotonin levels in the serum and hairs of Holstein dairy cows exposed to cold winter","authors":"J. Ghassemi Nejad,&nbsp;H.G. Lee","doi":"10.1016/j.domaniend.2022.106768","DOIUrl":"10.1016/j.domaniend.2022.106768","url":null,"abstract":"<div><p>Previous studies showed that coat color significantly affects hair cortisol levels but not serum cortisol and serotonin levels in heifers and dairy cows under heat stress conditions. As a follow-up study, we tested whether both serum and hair cortisol and serotonin levels in winter-housed dairy cows were affected by coat color (black vs white). Twenty multiparous high-yielding dairy cows (DIM = 110 ± 25, milk yield = 35 ± 2.1 kg) were assigned to one of the following groups: 1) black coat color (BCC; over 85% of coat black, n = 14) and 2) white coat color (WCC; over 85% of coat white, n = 6). The experimental period lasted 60 d (from December to February), during which the animals were kept in a building with free stalls that had dry river sand bedding. Blood was harvested for 3 consecutive days at the end of the study. Hair was harvested from the forehead of each individual at the beginning and on the end-day of the study. Cortisol and serotonin hormones were measured in serum and hair. Data were analyzed using t-test. The results revealed that cows with BCC had lower hair cortisol and higher hair serotonin levels than those with WCC (<em>P</em> &lt; 0.05). No differences in serum cortisol levels were observed between cows with WCC and BCC (<em>P</em> &gt; 0.05). The serum serotonin level was lower in cows with WCC compared to the BCC group (<em>P</em> &lt; 0.05). Taken together, coat color significantly affected stress levels indicated by higher hair cortisol and lower hair serotonin levels in WCC cows in addition to lower serum serotonin levels in the corresponding animals. This feature of coat color should be considered as a management tool, particularly in countries with long winters.</p></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"82 ","pages":"Article 106768"},"PeriodicalIF":2.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33497555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Group or individual housing does not reduce socio-sexual and reproductive responses in anestrous goats during the first contact with the photo-stimulated buck","authors":"F.J. González ,&nbsp;L. Sifuentes ,&nbsp;R. Ulloa-Arvizu ,&nbsp;M.J. Palomo Peiró ,&nbsp;G. Duarte ,&nbsp;I.G. Fernández","doi":"10.1016/j.domaniend.2022.106772","DOIUrl":"10.1016/j.domaniend.2022.106772","url":null,"abstract":"<div><p>Herein, we examined the effect of the type of housing (individual vs group housing) of anestrus female goats on plasma cortisol concentrations and socio-sexual behaviors during first contact with photo-stimulated male goats and determined the impact on sexual and reproductive responses after 15 d of contact with photo-stimulated males. Therefore, after weaning, 10 females each were individually and group-housed, respectively. Ten bucks were rendered sexually active by exposure to artificially long days (16 h of light and 8 h of darkness per day) for 2.5 mo. During the naturally increasing photoperiod, 15-mo-old females were exposed and maintained with males. On day 0, during the first contact with males, individually- and group-housed females exhibited similar plasma cortisol concentrations (22.6 vs 27.4 ng/mL, respectively). Likewise, socio-sexual behaviors did not differ between examined groups on day 0. Moreover, the interval from first contact with males to the first estrus, short and normal ovulatory cycles, ovulation, fertility, and prolificacy rates were similar between differently housed females. Furthermore, mounting attempts did not differ between males in contact with either female group. In conclusion, individually- and group-housed anestrus females displayed elevated and similar plasma cortisol concentrations during first contact with photo-stimulated males and similar socio-sexual behaviors and reproductive responses when exposed to photo-stimulated males.</p></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"82 ","pages":"Article 106772"},"PeriodicalIF":2.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40683468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the effect of auditory stimuli on activity levels, milk yield and faecal glucocorticoid metabolite concentrations in Holstein cows","authors":"L.-M. Erasmus ,&nbsp;E. van Marle-Köster ,&nbsp;A. Masenge ,&nbsp;A. Ganswindt","doi":"10.1016/j.domaniend.2022.106767","DOIUrl":"10.1016/j.domaniend.2022.106767","url":null,"abstract":"<div><p>Health and welfare are inextricably linked within efficient and sustainable dairy production, and several potential risk factors may affect the well-being of dairy cows, including chronic stress. Although auditory stimuli could be used as a tool to decrease the potential stress that cows might experience, it is seldom applied to livestock production systems due to the perception that enrichment is an unnecessary expense. This study aimed to explore the effect of auditory stimuli as a form of enrichment in a Holstein herd by monitoring fecal glucocorticoid metabolite (fGCM) concentrations (a non-invasive, stress-associated biomarker). Cow activity level and milk yield were also measured. Nine cows in their second and third lactation were divided into 3 groups, using a Latin Square experimental design, exposing each cow group to each of the 3 treatments, namely constant exposure (CE), limited exposure (LE), and no exposure (NE) to classical music. FGCMs were quantified using a group-specific enzyme immunoassay detecting 11,17-dioxoandrostanes. Compared to LE and NE animals, cows exposed to constant music had significantly lower fGCM concentrations (<em>P</em> = 0.012), as well as higher milk yields (<em>P</em> &lt; 0.0001) and lowered activity levels during the morning (<em>P</em> = 0.005) and the evening activity period (<em>P</em> = 0.048). These findings indicate that auditory stimuli in the form of classical music may have a positive effect on the welfare of cows as well as milk yield, which hold economic benefits for the producer and potentially reduces the number of cows needed for profitable production.</p></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"82 ","pages":"Article 106767"},"PeriodicalIF":2.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33541417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Anabolic implants alter abundance of mRNA involved in muscle growth, metabolism, and inflammation in the longissimus of Angus steers in the feedlot","authors":"C.C. Reichhardt ,&nbsp;J.M. Cuthbert ,&nbsp;L.A. Motsinger ,&nbsp;T.J. Brady ,&nbsp;R.K. Briggs ,&nbsp;A.J. Thomas ,&nbsp;K.J. Thornton","doi":"10.1016/j.domaniend.2022.106773","DOIUrl":"10.1016/j.domaniend.2022.106773","url":null,"abstract":"<div><p>The majority of beef cattle in the United States often receive at least one anabolic implant resulting in improved growth, feed efficiency, and environmental and economic sustainability. However, the physiological and molecular mechanisms through which anabolic implants increase skeletal muscle growth of beef cattle remain elusive. The objective of this study was to identify transcriptional changes occurring in skeletal muscle of steers receiving anabolic implants containing different steroid hormones. Forty-eight steers were stratified by weight into 1 of 4 (n = 12/treatment) implant treatment groups: (1) estradiol (ImpE2; 25.7 mg E2; Compudose, Elanco Animal Health, Greenfield, IN), (2) trenbolone acetate (ImpTBA; 200 mg TBA; Finaplix-H, Merck Animal Health, Madison, NJ), (3) combination (ImpETBA; 120 mg TBA + 24 mg E2; Revalor-S, Merck Animal Health), or (4) no implant (CON). Skeletal muscle biopsies were taken from the longissimus 2 and 10 d post-implantation. The mRNA abundance of 94 genes associated with skeletal muscle growth was examined. At 10 d post-implantation, steers receiving ImpETBA had greater (<em>P</em> = 0.02) myoblast differentiation factor 1 transcript abundance than CON. Citrate synthase abundance was increased (<em>P =</em> 0.04) in ImpETBA steers compared to CON steers. In ImpE2 steers 10 d post-implantation, muscle RING finger protein 1 decreased (<em>P =</em> 0.05) compared to CON steers, and forkhead box protein O4 decreased (<em>P =</em> 0.05) in ImpETBA steers compared to CON steers. Interleukin-6 abundance tended to be increased (<em>P =</em> 0.09) in ImpE2 steers compared to both ImpETBA and CON steers. Furthermore, interleukin-10 mRNA abundance tended to be increased (<em>P =</em> 0.06) in ImpTBA steers compared to ImpETBA steers. Leptin receptor abundance was reduced (<em>P =</em> 0.01) in both ImpE2 and ImpTBA steers when compared to CON steers. Abundance of phosphodiesterase 4B was increased (<em>P =</em> 0.04) in ImpTBA steers compared to CON steers 2 d post-implantation. Taken together, the results of this research demonstrate that estradiol increases skeletal muscle growth via pathways related to nutrient partitioning and mitochondria function, while trenbolone acetate improves steer skeletal muscle growth via pathways related to muscle growth.</p></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"82 ","pages":"Article 106773"},"PeriodicalIF":2.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40466523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}