Levels of corn meal based supplement in Nellore steers finished on pasture in the dry season: performance, carcass characteristics and pasture evaluation

摘要

The objective of this study was to evaluate the availability of pasture components, average daily gain and carcass characteristics of Nellore steers receiving supplements in the finishing phase during the dry season. The experiment was carried out on Brachiaria brizantha, cv. Marandu pasture, in six nine-hectare paddocks. Forty-eight 30 month old Nellore steers with 412 +/- 16 kg initial weight were randomly distributed in six groups of eight animals. Each group was placed in a paddock and was weighed at the beginning and at every 21 days, for 84 days. Increasing levels of supplements were used: 0.25, 0.5, 1.0, 2.0, and 4.0 kg/animal. day, in comparison to a supplement control that received only mineral mixture. The supplements, except the control, presented variable levels of crude protein (87.4 to 25.0% of the dry matter), and proportions of mineral mixture: urea: corn meal of 25: 25: 50, 15: 15: 70, 10: 10: 80, 5: 5: 90, and 2.5: 2.5: 95 for 0.25, 0.5, 1.0, 2.0, and 4.0 kg/animal. day, respectively, since that urea was used as supplement intake controller. The supplementation levels were evaluated by regression in a randomized complete design. The proportion of stem and dead leaf increased over the experimental periods, characterizing the dry season. There was increasing linear effect on the final live weight, average daily gain and average daily gain per period as a function of the supplement intake, and average daily gain as a function of the crude protein and intake of total digestible nutrients. The supplement levels have an increasing linear effect on the carcass weight and fat thickness and quadratic effect for carcass yield.