Desempenho de bovinos em pastejo durante o período chuvoso recebendo diferentes suplementos minerais

Abstract

The objective of the work was to evaluate the performance of beef heifers receiving two types of additives via mineral supplement. The treatments were arranged in a randomized block design and consisted of three supplementation strategies, being the mineral supplement (SM), mineral supplement with salinomycin (SS) and mineral supplement with tannin + salinomycin (STS), with an expected consumption of 18-27 , 33-44 and 33-44 g per 100 kg BW day-1. 36 Nellore heifers with an initial weight of 226 kg were used, in a phase characterized as breeding. Thus, each treatment was represented by 12 animals. The agronomic and recurrent characteristics of the forage did not differentiate (p> 0.05) between treatments. This was expected, since the factors that affect the dynamics of the pasture were the same for everyone. Supplement consumption has a difference (p <0.05) between the treatments studied, which was already foreseen, since the SM treatment supplement had an expected consumption lower than the others. However, the additives dissipated less than expected consumption, causing the additive intake to be compromised. The average daily gain of the animals was not affected (p> 0.05) with the addition of additives in mineral supplements. The performances were 0.658, 0.758, 0.679 respectively for the SM, SS, STS treatments. The consumption of supplement below the expected may have influenced this result. Another factor is that without the additives, the animals already present a good performance, making it more difficult to increase the gain when the animals are in well-managed pastures. With that it is standard that the addition of tannin and / or salinomycin diet of beef heifers, taking mineral supplement as a vehicle for ingestion, does not change the performance of animals consuming well-managed pasture in the water period.