Influência de diferentes estratégias de suplementação sobre o comportamento ingestivo de forragem de bovinos

Abstract

Brazilian beef cattle farming is characterized by the fact that a large part of the herd is raised exclusively on pasture. Throughout the year, the forage undergoes quantitative and qualitative changes, resulting in oscillations in the performance of the animals. The adoption of supplementary strategies emerges as an alternative for maintaining or improving the performance of animals, as it consists of supplementing nutrients when forage is not able to meet all nutritional requirements. Given the aforementioned facts, the objective of this study was to observe the relationship between the supply of different supplements and the change in the ingestive behavior of cattle on pasture. Five crossbred animals, with an average weight of 520 kg, equipped with permanent ruminal cannulas, were randomly distributed in a Latin square design (5x5). The animals were kept in individual paddocks of approximately 0.2 hectare, equipped with a trough and drinker, in Urocloa brizantha cv. Marandu (Syn Brachiaria). The experimental period consisted of 12 days, where treatments were provided every day, with collections (blood, feces and urine) being performed on the 11th day and the behavior analysis on the 12th. To evaluate the effects of diet on ingestive behavior, the following model was adopted: Yijl = μ + Ai + Pj + Dl + erijl; where Yijl = dependent variable, μ = overall mean, Ai = animal effect (i = 1 to 5), Pj = period effect (j = 1 to 5), Dl = diet effect and eijl = experimental error. The use of different supplements did not change the animals' grazing behavior between treatments, and increased DM intake. The higher consumption of protein-energy supplement (SP4) provided the supply of a greater amount of crude protein in relation to the protein supplement (SP3), and this greater intake may result in greater weight gain. The lower consumption of the mineral supplement (SP1) was able to encourage the animals to graze for a similar time to the other treatments, which is a positive point, since the lower levels of CP, NNP and TDN are present in its composition.