EFEITO DA PROTEÍNA E ENERGIA NA REPRODUÇÃO DE FÊMEAS BOVINAS

Abstract

Dairy production in Brazil is characterized by many challenges. Even though the country has the largest commercial herd in the world, the dairy cattle industry has low production and reproduction rates. Regarding nutrition, it is important to highlight that it plays a crucial role in bovine reproductive activity, concerning the nutrients ingested that have a direct influence on the energy and protein percentage of the diet, acting directly and indirectly on reproductive metabolism. Reproduction is one of the tasks primarily impaired in cases of disharmony. Adequate nutrient intake results in increased concentrations of insulin, somatomedina C (IGF I), and leptin in the plasma, increases body fat stores, preventing reproductive problems. Protein is an important nutrient for animal life. In cattle, a large part of this protein comes from the microbial activity of the rumen, which in the animal's body has the functions of growth, maintenance of tissues, immunity, control and generation of nerve impulses, enzymatic catalysis, as well as regulation of metabolism. Thus, protein ensures the development of the animal's homeostasis, ensuring its reproductive efficiency. As for the energy part, glucose is the only energy source used by the neural system. It is important to emphasize that energy restriction in the animal can cause embryonic mortality, stillbirths, weak offspring, reduced growth, decreased fertility, and metabolic disorders capable of intensifying the aforementioned effects, potentially leading to the animal's death and delaying the appearance of the first postpartum estrus. We then conclude that the protein-energy relationship is closely linked to the reproductive success of any herd, with supplementation at adequate levels improving all reproductive indices of the breeding females, from hormone release, body condition score (BCS), conception, to birth, as well as the interval until the next pregnancy. Just as the imbalance of these nutrients can lead to a series of harmful disruptions for the conception of a new pregnancy, as well as for the proper development of the fetus.