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Sanford CD, Owen MPT, Oosthuizen N, Fontes PLP, Vonnahme KA, Nelson M, Reyaz A, Lemley CO, DiLorenzo N, Cliff Lamb G. Effects of administering exogenous bovine somatotropin to beef heifers during the first trimester on conceptus development as well as steroid- and eicosanoid-metabolizing enzymes. J Anim Sci 2021; 99:6136220. [PMID: 33587143 DOI: 10.1093/jas/skab050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 02/10/2021] [Indexed: 12/28/2022] Open
Abstract
The aim of this study was to evaluate the effect of bovine somatotropin (bST) on fetal and placental development during the first third of gestation in beef heifers. Angus heifers (n = 97) were randomly assigned to either receive a 500-mg injection of bST (BST) biweekly on days 0, 15, 29, 43, and 57 of gestation or not receive bST (CTL) throughout the experiment. Body weight (BW) was assessed on days -9, -3, 0, 15, 22, 29, 43, 50, 57, 64, and 77, while blood samples were collected on days 0, 22, 50, and 64. Pregnancy status was determined via transrectal ultrasonography on days 29 and 64. A subset of pregnant heifers (BST, n = 7; CTL, n = 5) were harvested on day 84, and complete gravid reproductive tracts and liver tissue were collected for analysis. Cytochrome P450 1A (CYP1A), 2C (CYP2C), 3A (CYP3A), and uridine 5'-diphospho-glucuronosyltransferase (UGT) activities were determined. Mean change in BW and average daily gain of heifers between fixed-time artificial insemination (day 0) and day 77 did not differ between treatments (P ≥ 0.05). Mean concentrations of insulin-like growth factor 1 (IGF-1) were greater (P < 0.001) in BST (347 ± 27.7 ng/mL) compared with CTL (135 ± 32.8 ng/mL) heifers. Mean placental weight, fetal membrane weight, uterine weight, and ovarian and corpus luteum (CL) weights, as well as fetal morphometric data, did not differ (P ≥ 0.05) between treatments. However, BST heifers had greater (P = 0.03) quantities of combined fetal fluid compared with CTL (521.6 ± 22.9 vs. 429.6 ± 27.14 g, respectively). Tendencies were observed for BST heifers to have reproductive tracts with fewer placentomes (P = 0.08) and fetuses with greater umbilical diameters (P = 0.09) compared with CTL. The activity of CYP1A did not differ (P ≥ 0.05) within the maternal and fetal liver, caruncle, cotyledon, or CL tissue samples between treatments. Furthermore, CYP3A activity was only observed in maternal liver samples and was not different between treatments (P ≥ 0.05). Interestingly, CYP2C activity was greater (P = 0.01) in the liver of BST vs. CTL heifers, and UGT activity was greater (P = 0.02) in the CL from BST heifers compared with CTL. In conclusion, the administration of bST during the first third of gestation increased plasma concentrations of IGF-1, which resulted in an increase in fetal fluid, decrease in placentome number, and greater umbilical diameter, but failed to alter fetal development.
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Affiliation(s)
- Carla D Sanford
- Department of Animal and Range Sciences, Montana State University, Bozeman, MT, USA
| | - Megan P T Owen
- College of Agricultural Sciences and Natural Resources, Texas A&M University-Commerce, Commerce, TX, USA
| | - Nicola Oosthuizen
- Department of Animal Science, Texas A&M University, College Station, TX, USA
| | - Pedro L P Fontes
- Department of Animal and Dairy Science, University of Georgia, Athens, GA, USA
| | | | - Megan Nelson
- Department of Animal Science, North Dakota State University, Fargo, ND, USA
| | - Arshi Reyaz
- Department of Animal Science, North Dakota State University, Fargo, ND, USA
| | - Caleb O Lemley
- Department of Animal and Dairy Sciences, Mississippi State University, Mississippi State, MS, USA
| | - Nicolas DiLorenzo
- North Florida Research and Education Center, University of Florida, Marianna, FL, USA
| | - Graham Cliff Lamb
- Department of Animal Science, Texas A&M University, College Station, TX, USA
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FUKUI Y, ITAGAKI R, ISHIDA N, OKADA M. Effect of Different hCG Treatments on Fertility of Estrus-Induced and Artificially Inseminated Ewes During the Non-Breeding Season. J Reprod Dev 2001. [DOI: 10.1262/jrd.47.189] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Yutaka FUKUI
- Laboratory of Animal Genetics and Reproduction, Obihiro University of Agriculture and Veterinary Merdicine
| | - Ryoko ITAGAKI
- Laboratory of Animal Genetics and Reproduction, Obihiro University of Agriculture and Veterinary Merdicine
| | - Naohisa ISHIDA
- Laboratory of Animal Genetics and Reproduction, Obihiro University of Agriculture and Veterinary Merdicine
| | - Midori OKADA
- Laboratory of Animal Genetics and Reproduction, Obihiro University of Agriculture and Veterinary Merdicine
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