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.
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