| Effects of lasalocid on circulating concentrations of leptin and insulin-like growth factor-I and reproductive performance of postpartum Brahman cows. | |
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MedLine Citation:
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PMID: 12817482 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Objectives were to determine effects of lasalocid on reproductive performance and serum concentrations of leptin and IGF-I, and to correlate concentrations of leptin and IGF-I with reproductive performance of beef cows. Forty-one purebred, multiparous Brahman cows were blocked to control (C; n = 20) or lasalocid (L; n = 21) treatments by BW, BCS, and predicted calving date. Treatment began 21 d before expected calving. Cows were each fed 1.4 kg daily of an 11:1 corn:soybean meal supplement, with the L group receiving 200 mg of lasalocid/cow daily. Cows and calves were weighed, and cow BCS was assessed at calving and at 28-d intervals thereafter. Blood samples were collected weekly precalving, at parturition, and twice weekly thereafter. Sterile marker bulls were maintained with cows for estrous detection. Six days after estrus, ovaries were evaluated for corpus luteum formation, and blood samples from d 6, 7, and 8 after estrus were collected. Serum samples were assayed for progesterone (P4), IGF-I, and leptin concentration. Progesterone concentrations > 1 ng/mL were considered indicative of a functional corpus luteum. Treatment ended after completion of a normal estrous cycle, and cows removed from treatment were placed with a fertile bull equipped with a chinball marker. There were no treatment differences in calving date, calf sex, cow BW, BCS, calf BW, calf ADG, or in serum concentrations of P4, IGF-I, or leptin. Prepartum cow ADG was increased (P < 0.01) in L cows and tended (P < 0.011) to be increased from calving to d 56 after calving in L cows. Postpartum interval (PPI) was not affected by treatment; however, a greater percentage (P < 0.05) of L cows conceived by 90 d after calving (43% L vs. 15% C). First-service conception rate tended (P < 0.08) to be greater in L vs. C cows (68 vs. 40%), but pregnancy rate was not different (P < 0.12; 86% for L vs. 65% for C). There were no treatment differences (P > 0.18) for serum IGF-I concentrations. At calving, leptin was positively correlated with IGF-I (P < 0.04; r = 0.32), BCS (P < 0.06; r = 0.29), and cow BW (P < 0.02; r = 0.36), and was negatively correlated with PPI (P < 0.06; r = -0.29). These results provide evidence that feeding an ionophore before calving and during the postpartum period may increase the number of cows that rebreed to maintain a yearly calving interval. Cows with higher concentrations of leptin postpartum may exhibit shorter PPI. |
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Authors:
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T A Strauch; D A Neuendorff; C G Brown; M L Wade; A W Lewis; D H Keisler; R D Randel |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Journal of animal science Volume: 81 ISSN: 0021-8812 ISO Abbreviation: J. Anim. Sci. Publication Date: 2003 Jun |
Date Detail:
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Created Date: 2003-06-23 Completed Date: 2003-12-08 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 8003002 Medline TA: J Anim Sci Country: United States |
Other Details:
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Languages: eng Pagination: 1363-70 Citation Subset: IM |
Affiliation:
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Texas Agricultural Experiment Station, Overton, TX 75684, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animal Feed Animals Birth Weight Cattle / blood, physiology* Estrus Detection Female Insulin-Like Growth Factor I / metabolism* Ionophores / pharmacology* Lasalocid / pharmacology* Leptin / blood* Male Postpartum Period Pregnancy Progesterone / blood Random Allocation Reproduction / drug effects* Time Factors |
| Chemical | |
Reg. No./Substance:
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0/Ionophores; 0/Leptin; 25999-31-9/Lasalocid; 57-83-0/Progesterone; 67763-96-6/Insulin-Like Growth Factor I |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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