Farelo de arroz integral na recria de bezerras de corte em azevém

Abstract

The experiment was carried out with the objective of evaluating the gross margin, the productive and reproductive performance of beef heifers kept exclusively on ryegrass pasture (Lolium multiflorum Lam.) or ryegrass receiving 0.5 and 1.0% of body weight (BW) of whole rice bran as supplement, provided daily at at 2:00 p.m. The grazing method was the rotational and the interval between grazings was set by the thermal sum required for the appearing of 1.5 ryegrass leaf (187.5º C). The experimental design was completely randomized with repeated measures, three feeding systems and two and two area replications. Heifers in different feeding systems were kept in similar forage mass and canopy height when they came out of plots in all paddocks. The heifers average daily gain did not differ between the feeding systems. The stocking rate and weight gain per area were higher when heifers received 1.0% BW of whole rice bran. The provision of 0.5% BW of WRB allowed stocking rate and capacity gain for intermediate area between the other feeding systems. The higher gross margin was observed when heifers received 0.5% BW. The variable cost obtained for the different feeding systems showed increasing behavior depending on the WRB levels, surpassing the exclusive use of ryegrass in 37.2% and 60.6%. The final body weight, body condition score and reproductive tract score did not differ between the feeding systems. Considering an adult animal with an average body weight of 450 kg, the heifers at the beginning of the experiment showed 34% of mature body weight and final average body weight of 56% of adult weight.