Bovine somatotropin increases the pregnancy rate in fixed-time artificial insemination in beef cattle.

Autor: Valle VM; Programa de Pós-Graduação em Ciência Animal, Pontifícia Universidade Católica do Paraná (PUC), Curitiba, Paraná, Brazil., Fazzano CJ; Fazzembryo Consultoria Técnica, Araçatuba, São Paulo, Brazil., Segui MS; Programa de Pós-Graduação em Ciência Animal, Pontifícia Universidade Católica do Paraná (PUC), Curitiba, Paraná, Brazil., Souza FA; Federal University of Paraná, Curitiba, Brazil., Kaled TXA; Programa de Pós-Graduação em Ciência Animal, Pontifícia Universidade Católica do Paraná (PUC), Curitiba, Paraná, Brazil., Gomes MGT; Federal University of North Tocantins, Araguaína, Tocantins, Brazil., Nogueira E; EMBRAPA Beef Cattle Center, Campo Grande, Mato Grosso do Sul, Brazil., Kozicki LE; Programa de Pós-Graduação em Ciência Animal, Pontifícia Universidade Católica do Paraná (PUC), Curitiba, Paraná, Brazil.
Jazyk: angličtina
Zdroj: Reproduction in domestic animals = Zuchthygiene [Reprod Domest Anim] 2024 Jun; Vol. 59 (6), pp. e14642.
DOI: 10.1111/rda.14642
Abstrakt: This study evaluated the effect of bovine somatotropin (bST) on pregnancy rate (PR) and size of the dominant follicle (DF) on the day of intravaginal progesterone (P4) removal in protocols for fixed-time artificial insemination (FTAI). Bos indicus (Nellore) females (n = 392) were distributed into three groups. The control group (CG; n = 92) received an intravaginal P4 device + estradiol benzoate on day (d)0; prostaglandin F2α on d7 (first application); removal of P4 + estradiol cypionate (EC) + PGF2α (second application) + ultrasound (US) of the DF on d9; the FTAI was performed on d11; and pregnancy diagnosis (PD) was performed on d45. The bST group (bSTG; n = 142) underwent the same protocol as the CG, except that the animals received 125 mg of bST on d7. The equine chorionic gonadotropin (eCG) group (eCGG; n = 158) underwent the same protocol as the CG, except that the animals received 300 IU of eCG on d9. The PRs of the bSTG, eCGG, and CG were 48%, 48%, and 35%, respectively (p < .05); the bSTG and eCGG showed greater PRs, with follicles 6-7.9 mm (p < .05) and 8-8.9 mm in diameter, respectively. The bSTG exhibited a greater dimension of the DF on d9 of the protocol (p < .05). The eCGG had higher PRs with a body condition score (BCS) of 2.5, and the bSTG had a BCS of 3.0 (p < .05). It was concluded that bST increased PR, bST showed better performance in smaller DF and larger follicular diameter on d9 of the protocol, eCG acted better on animals with lower BCSs, and bST can be used in FTAI.
(© 2024 Wiley‐VCH GmbH. Published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
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