Sales José Nélio de Sousa, Pugliesi Guilherme, Carvalho Laís Reis, Simões Luiz Manoel Sousa, Lemos Lucas Araujo, Vicente Matheus Pedroso, Silva Rafael Resende Rabelo, Baruselli Pietro Sampaio
Departamento de Medicina Veterinária, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brasil.
Faculdade de Zootecnia e Medicina Veterinária, Universidade Federal de Lavras, Lavras, MG, Brasil.
Anim Reprod. 2024 Aug 12;21(3):e20240034. doi: 10.1590/1984-3143-AR2024-0034. eCollection 2024.
The reproductive efficiency of the herd is correlated with higher productivity in livestock. Reproduction biotechniques, such as ovulation synchronization protocols, are important to optimize production and accelerate genetic profit in beef and dairy herds. The objective of this review is to describe the evolution over the last 40 years of the artificial insemination (AI) and the timed-AI (TAI) protocols in cattle from a Brazilian perspective. TAI protocols are based on synchronizing emergence of the wave of follicular growth, controlling circulating progesterone (P4) concentrations, stimulating the final growth of the follicle and inducing a synchronized ovulation. Hormonal alternatives that optimize the response at the end of the protocol and strategies to induce final follicle growth and ovulation in categories of females with low expression of estrus are described. Furthermore, the potential positive effect of previous exposure to injectable P4 on fertility of and cows is also discussed.
畜群的繁殖效率与家畜更高的生产力相关。繁殖生物技术，如排卵同步方案，对于优化牛肉和奶牛群的生产以及加速遗传效益至关重要。本综述的目的是从巴西的角度描述过去40年牛人工授精（AI）和定时人工授精（TAI）方案的演变。TAI方案基于同步卵泡生长波的出现、控制循环孕酮（P4）浓度、刺激卵泡的最终生长以及诱导同步排卵。描述了在方案结束时优化反应的激素替代方法以及在发情表达低的雌性类别中诱导卵泡最终生长和排卵的策略。此外，还讨论了先前注射P4对母牛和奶牛生育力的潜在积极影响。
