Data/hora: 17/06/2024 11:09:42

Provedor de dados: | 65
País: | Brazil
Título: | Consequences of eight consecutive applications of equine chorionic gonadotropin on ovarian follicle development and ovulation in  bos indicus cows
Autores: | Stuhr,Bhárbara Delboni; Gil,Isaac Santos; Lacerda,Tracy Ferreira; Favoreto,Mauricio Gomes; Loureiro,Bárbara.
Data: | 2016-11-01
Ano: | 2016
Palavras-chave: | Corpus luteum; ECG; Fertility; Immunity; FTAI.
Resumo: | ABSTRACT: The equine chorionic gonadotropin (eCG) is a glycoprotein produced in mare endometrial calices. In bovine, it is used in estrus synchronization protocols. However, studies have shown that it is potentially immunogenic and its effect can decrease after repetitive use. This study aimed to evaluate antral follicle dynamics, corpus luteum (CL) and ovulation rate in bos indicus cows submitted to an estrus synchronization protocol in association with eCG for eight times consecutively. Ten cyclical, multiparous, and pasture raised beef cows were divided into two groups: control group (n=5) and eCG group (n=5). In 30 day interval, all animals were synchronized with the same estrogen/progesterone based protocol, totalizing 8 re-synchronizations. Cows in the treatment group received 300IU eCG 48 hours prior to the presumable ovulation. Ultrassound examinations were performed on Day 4 of the protocol (approximately 1.5 days after follicle recruitment) to count antral follicles, on Day 10, to count antral follicles and to measure size of the largest follicle and on Day 18 to measure the diameter of the CL. No difference (P&gt;0.05) between follicular growth and size of the pre-ovulatory follicle was reported between groups. Cows treated with eCG had a larger (P&lt;0.05) CL and increased (P&lt;0.05) ovulation rate (18mm and 92%, respectively) when compared with control group (14.1mm and 80%, respectively). Furthermore, consecutive treatments did not affect CL nor ovulation rates. In conclusion, eCG treatment increased CL size and ovulation rate even after 8 consecutive treatments.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782016001102018
Editor: | Universidade Federal de Santa Maria
Relação: | 10.1590/0103-8478cr20160091
Formato: | text/html
Fonte: | Ciência Rural  v.46 n.11 2016
Fonte: | info:eu-repo/semantics/openAccess