Fatores que afetam a qualidade do sêmen de touros Nelore

Abstract

Beef cattle production is one of the main sectors of Brazilian agribusiness, and reproductive efficiency is an essential factor for increasing productivity and profitability in production systems. In this context, semen quality plays a fundamental role in the success of natural breeding, directly influencing herd fertility rates. This study aimed to evaluate the influence of age, body weight, and scrotal circumference on the semen quality of purebred Nelore bulls. A total of 119 bulls, approximately 24 months of age, from a commercial farm located in the municipality of Ipiaçu, Minas Gerais, Brazil, were evaluated. During the breeding soundness examination, data were collected on body weight, scrotal circumference, sperm motility, sperm vigor, and the percentages of major and minor sperm defects. The data were analyzed using analysis of variance (ANOVA), adopting a significance level of 5% (P < 0.05). The results showed that age significantly influenced body weight, scrotal circumference, sperm motility, and sperm vigor. Body weight had a significant effect only on scrotal circumference, whereas scrotal circumference did not influence the evaluated semen quality parameters. It was concluded that, under the conditions of this study, age was the main factor associated with semen quality in purebred Nelore bulls, while body weight and scrotal circumference did not significantly affect most of the seminal characteristics evaluated. These findings reinforce the importance of the combined evaluation of reproductive parameters in the selection of bulls with greater reproductive potential.