Nutritional Influences on Reproductive Performance in Breeding Bulls

Abstract

Reproductive performance in animals is a productivity parameter shaped by the individual or combined effects of factors such as genetics, environment, climate, nutrition, management, stress and temperament. Among these factors, nutrition plays a significant role in maximising the reproductive potential of bulls. Inadequate or unbalanced nutrition leads to a reduction in androgen secretion and a decline in sperm quality in adult male animals. Consequently, the bull’s nutritional status is one of the primary factors determining sperm quantity and quality. In particular, by feeding calves a ration with high nutritional value during the pre and post-weaning stages and ensuring adequate nutritional intake, the bulls’ reproductive function can be maximised. Furthermore, physical health, which is directly linked to the bull’s reproductive performance, can be achieved by reaching an appropriate live weight through appropriate feeding strategies. An optimal feeding program not only helps bulls remain physically healthy but also influences gonadotropin secretion and, consequently, their reproductive performance. Therefore, ensuring an adequate intake of energy, protein, minerals and vitamins at different stages of growth and reproduction is crucial for maximising the reproductive potential of bulls. This review examines experimental and field studies covering the effects of certain nutrients on key reproductive parameters such as semen quality, hormonal balance and spermatogenesis, which influence the reproductive performance of breeding bulls, as well as feeding strategies implemented to improve their fertility levels.