Níveis de suplementação energética para bovinos recriados em pastagem de inverno

Abstract

This study aimed to evaluate the effects of different levels of energy supplementation on the performance of beef cattle during the growing phase. The animals were maintained on a winter pasture composed of dual-purpose wheat, cultivar BRS Tarumaxi (Triticum aestivum), intercropped with ryegrass (Lolium multiflorum). The evaluated treatments were: Control (mineral supplement), T4 (0.4% of body weight in energy supplement), and T8 (0.8% of body weight in supplement). The supplement consisted of ground corn grain. The experiment was conducted at the Beef Cattle Teaching and Research Unit of the Federal University of Technology – Paraná (UTFPR), at the Experimental Farm located in Dois Vizinhos, PR. Twenty-seven Purunã cattle, approximately 18 months old and with an initial average body weight of 310 kg, were used. The animals remained on the pasture for 108 days, until the end of the forage production cycle. The experimental area, comprising seven hectares, was divided into nine paddocks of 0.700 ha, arranged in a randomized block design with three replications. Forage mass per hectare was estimated using the double-sampling technique, and two exclusion cages per paddock were installed to determine forage accumulation rate. Despite the initial expectation of differences in individual performance, no significant effect of supplementation was observed on average daily gain (ADG), which ranged from 1.12 to 1.19 kg/day. However, liveweight gain per hectare per day (LWG/ha/day) was higher in the treatment receiving 0.8% supplementation compared with the control, increasing from 451.72 to 593.31 kg/ha/day. It is concluded that energy supplementation at levels equal to or greater than 0.8% of body weight allows an increase in stocking rate and gain per area without compromising individual animal performance.