Effect of weight gain rates in the post-weaning phase and forage allowance in the finishing phase with high supplementation on performance of Nellore cattle

Abstract Text: The study analyzed the effect of forage allowance in the finishing phase of beef cattle fed high levels of supplementation and its interaction with the rate of weight gain in the post-weaning phase. Sixty four non-castrated Nellore cattle with an average body weight (BW) of 386.0 kg, were distributed into 16 paddocks (experimental units) of Brachiaria brizantha cv. Marandu  and fed 2% of their BW in supplement containing 34% of corn, 51% of citrus pulp pellets and 15% of mineral mix. Treatments consisted of animals managed during the post-weaning phase on 15 or 35 cm tall pastures receiving mineral mix 50g/100 Kg BW and sub-divided into lots with low and high forage allowance in the finishing phase. In the post-weaning phase, the pasture height provided different ADG (0.761 kg day^-1 for the 15 cm and 1.076 kg day^-1 35 cm pasture), and different forage allowances were obtained in the finishing phase, with the same stocking rate in the paddocks, with different initial masses (3.370 and 8.470 kg DM ha^-1) provided by the management of 15 and 35 cm tall pastures during the post-weaning phase, respectively. The experimental period was 120 days, in a completely randomized blocks design in a 2 × 2 factorial arrangement, in which data were analyzed by using a mixed model through the MIXED procedure of SAS (SAS 9.2), significance at P < 0.10 by the t test. The animals that had the lowest weight gain and were in the treatment with the highest forage allowance in finishing had the greatest ADG (1.123 kg day^-1; P = 0.02), and the other nutritional strategies did not differ from each other (P > 0.10), averaging 0.929; 0.901 (biggest gain in post-weaning and low and high bid on finishing respectively) and 0.920 kg day^-1(lower gain in post-weaning and finishing in low supply). The supplement intake was affected by the post-weaning treatment (P = 0.01) and no effect of forage allowance in the finishing was observed (P = 0.74). Animals kept on 35 cm pastures in the post-weaning started the finishing heavier  consumed more supplement (7.8 kg day^-1) than those reared on 15 cm pastures (7.3 kg day^-1). In relation the quantity of concentrate to gain 1 kg of BW, the animals on the lowest forage allowance level in the finishing showed an upward trend (P = 0.15; 7.7 vs 8.9 kg supplement kg BW). Supported by CAPES/UNESP/CONNAN.

Keywords: gain, consumed,  marandu