Effects of two estradiol esters (benzoate and cypionate) on the induction of synchronized ovulations in Bos indicus cows submitted to a timed artificial insemination protocol
Contribuinte(s) |
Universidade Estadual Paulista (UNESP) |
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Data(s) |
30/09/2013
20/05/2014
30/09/2013
20/05/2014
01/08/2012
|
Resumo |
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) The effects of estradiol benzoate (EB) and estradiol cypionate (EC) on induction of ovulation after a synchronized LH surge and on fertility of Bos indicus females submitted to timed AI (TAI) were evaluated. In Experiment 1, ovariectomized Nelore heifers were used to evaluate the effect of EB (n = 5) and EC (n = 5) on the circulating LH profile. The LH surge timing (19.6 and 50.5 h; P = 0.001), magnitude (20.5 and 9.4 ng/mL; P = 0.005), duration (8.6 and 16.5 h; P = 0.001), and area under the LH curve (158.6 and 339.4 ng/mL; P = 0.01) differed between the EB and EC treatments, respectively. In Experiment 2 (follicular responses; n = 60) and 3 (pregnancy per AI; P/AI; n = 953) suckled Bos indicus beef cows submitted to an estradiol/progesterone-based synchronization protocol were assigned to receive one of two treatments to induce synchronized ovulation: 1 mg of EB im 24 h after progesterone (P4) device removal or 1 mg of EC im at P4 device removal. There was no difference (P > 0.05) between EB and EC treatments on follicular responses (maximum diameter of the ovulatory follicle, 13.1 vs. 13.9 mm; interval from progesterone device removal to ovulation, 70.2 vs. 68.5 h; and ovulation rate, 77.8 vs. 82.8%, respectively). In addition, P/AI was similar (P < 0.22) between the cows treated with EB (57.5%; 277/482) and EC (61.8%; 291/471). In conclusion, despite pharmacologic differences, both esters of estradiol administered either at P4 device removal (EC) or 24 h later (EB) were effective in inducing an LH surge which resulted in synchronized ovulations and similar P/AI in suckled Bos indicus beef cows submitted to TAI. (C) 2012 Elsevier B.V. All rights reserved. |
Formato |
510-516 |
Identificador |
http://dx.doi.org/10.1016/j.theriogenology.2012.02.031 Theriogenology. New York: Elsevier B.V., v. 78, n. 3, p. 510-516, 2012. 0093-691X http://hdl.handle.net/11449/14820 10.1016/j.theriogenology.2012.02.031 WOS:000306538100005 WOS000306538100005.pdf |
Idioma(s) |
eng |
Publicador |
Elsevier B.V. |
Relação |
Theriogenology |
Direitos |
openAccess |
Palavras-Chave | #Bovine #Ovarian response #Estradiol #Tai #LH #Synchronization |
Tipo |
info:eu-repo/semantics/article |