Effects of eCG and FSH in timed artificial insemination treatment regimens on estrous expression and pregnancy rates in primiparous and multiparous Bos indicus cows
| Autor: | L.A. Scandiuzzi, L.A.C.L. Silva, José Camisão de Souza, L. M. S. Simoes, Pietro Sampaio Baruselli, M. P. Bottino, R. W. Girotto, J.P.M. Massoneto, José Nelio de Sousa Sales |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
endocrine system
Pregnancy Rate medicine.drug_class medicine.medical_treatment Chorionic Gonadotropin Drug Administration Schedule 03 medical and health sciences Follicle-stimulating hormone 0302 clinical medicine Endocrinology Animal science Food Animals Estrus Pregnancy Follicular phase medicine Animals HORMÔNIO FOLÍCULO-ESTIMULANTE Equine chorionic gonadotropin Insemination Artificial Estrous cycle 030219 obstetrics & reproductive medicine Estradiol business.industry Artificial insemination 0402 animal and dairy science food and beverages 04 agricultural and veterinary sciences General Medicine medicine.disease 040201 dairy & animal science Regimen Parity Estrogen Animal Science and Zoology Cattle Female Follicle Stimulating Hormone business |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| Popis: | Effects were evaluated in Bos indicus cows of eCG and FSH on follicular growth, estrous expression, and pregnancy per artificial insemination (P/AI) as a result of fixed-time artificial insemination (TAI). In Experiment 1, extent of timing-of-ovulation synchronization among cows was evaluated after imposing an estrogen/progesterone-based treatment regimen. At progesterone device removal (D8), cows were administered: eCG, or FSH or served as untreated Controls. In Experiment 2, percentage of cows P/AI was evaluated when the Experiment 1-treatment regimen was imposed. On D10, all cows were artificially inseminated. In Experiment 3, cows were assigned to two treatment groups (Control and eCG) on D8 to evaluate percentage of cows P/AI and estrous expression. In Experiment 1, follicular dynamics were similar among treatment groups. In Experiment 2, follicular growth was greater (P = 0.0001) with the eCG treatment. There was an interaction of treatment × parity (P = 0.007) on percentage of cows P/AI. There was a greater percentage of primiparous cows P/AI in the eCG-treated than Control and FSH-treated cows. There was a greater percentage of eCG-treated multiparous cows pregnant as a result of TAI than Control cows. There was an interaction of treatment × parity (P = 0.005) on P/AI in Experiment 3, in which the eCG effect was more pronounced in primiparous cows. Treatment with FSH, therefore, was not as effective as eCG in stimulation of follicular growth or enhancing percentage of cows pregnant as a result of TAI. Physiological effects of eCG, however, were also more evident in primiparous cows. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|