Evaluation of luteolysis, follicle size, and time to ovulation in Holstein heifers treated with two different analogs and doses of prostaglandin-F 2α .

Autor:	Umaña Sedó SG; Department of Large Animal Clinical Sciences, D. H. Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32610., Figueiredo CC; Department of Large Animal Clinical Sciences, D. H. Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32610., Gonzalez TD; Department of Large Animal Clinical Sciences, D. H. Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32610., Duarte GA; Department of Large Animal Clinical Sciences, D. H. Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32610., Ugarte Marin MB; Department of Large Animal Clinical Sciences, D. H. Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32610., Crawford CA; Department of Large Animal Clinical Sciences, D. H. Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32610., Pohler KG; Department of Animal Science, Pregnancy and Developmental Programming Area of Excellence, Texas A&M University, College Station 77843., Chebel RC; Department of Large Animal Clinical Sciences, D. H. Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32610; Department of Animal Sciences, University of Florida, Gainesville 32608., Bilby TR; Merck Animal Health, Madison, NJ 07940., Bisinotto RS; Department of Large Animal Clinical Sciences, D. H. Barron Reproductive and Perinatal Biology Research Program, University of Florida, Gainesville 32610. Electronic address: rsbisinotto@ufl.edu.
Jazyk:	angličtina
Zdroj:	Journal of dairy science [J Dairy Sci] 2022 Jun; Vol. 105 (6), pp. 5506-5518. Date of Electronic Publication: 2022 Apr 22.
DOI:	10.3168/jds.2021-21487
Abstrakt:	Objectives were to evaluate the effect of 2 analogs of PGF 2α (cloprostenol vs. dinoprost) and 2 doses (1 injection vs. 2 injections) on luteolysis, follicle diameter, hormonal concentrations, and time to ovulation in dairy heifers. Holstein heifers were fitted with automated estrus detection devices and had their estrous cycle synchronized using PGF 2α and an intravaginal insert containing progesterone. Heifers detected in estrus were blocked by weight and randomly assigned to 1 of 4 treatments in a 2 × 2 factorial arrangement: cloprostenol on d 7 after estrus (CLOx1; n = 45), cloprostenol on d 7 and 8 after estrus (CLOx2; n = 41), dinoprost on d 7 after estrus (DINx1; n = 43), or dinoprost on d 7 and 8 after estrus (DINx2; n = 44). Treatment with the first injection of PGF 2α was defined as experiment d 0. Area and blood flow of corpus luteum (CL) and diameter of follicles >5 mm were recorded every 12 h from d 0 to estrus and every 6 h thereafter until ovulation. Blood was sampled every 6 h from d 0 until ovulation. Heifers treated with cloprostenol had shorter interval to luteolysis (± SEM; CLOx1 = 23.5 ± 2.2, CLOx2 = 22.9 ± 2.2, DINx1 = 32.6 ± 2.7, DINx2 = 26.4 ± 2.1 h); however, time to ovulation was not affected by treatment. A smaller proportion of heifers treated with a single injection of PGF 2α underwent luteolysis compared with heifers treated with 2 injections (CLOx1 = 84.6 ± 6.2, CLOx2 = 100.0 ± 0.0, DINx1 = 59.7 ± 9.8, DINx2 = 96.3 ± 2.7%). Proportion of heifers that ovulated was smaller for DINx1 compared with other treatments (CLOx1 = 88.8 ± 5.1, CLOx2 = 100.0 ± 0.0, DINx1 = 55.2 ± 9.7, DINx2 = 94.4 ± 3.4%). Ovulatory follicle diameter was larger for DINx1 (18.2 ± 2.7 mm) compared with DINx2 (17.4 ± 2.7 mm), whereas dose did not affect the diameter of the ovulatory follicle in heifers treated with cloprostenol (CLOx1 = 17.6 ± 2.7 vs. CLOx2 = 17.8 ± 2.8 mm). Among heifers that underwent luteolysis, progesterone concentrations from 18 to 36 h after treatment were lesser in heifers treated with cloprostenol compared with those treated with dinoprost. Type of PGF 2α did not affect progesterone concentrations past 36 h from treatment; however, heifers treated with 2 PGF 2α injections had lesser progesterone concentrations and CL blood flow from 36 to 72 h after treatment compared with heifers that received a single PGF 2α injection. (© 2022, The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)
Databáze:	MEDLINE
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