Supplementation for beef cattle on Marandu grass pastures with different herbage allowances

Abstract

The objective of this study was to evaluate the performance of beef heifers on Stapf. cv. Marandu grass pastures that were managed at three herbage allowances under continuous grazing with a variable stocking rate and were provided with mineral mix supplement or supplements with energy and protein. Seventy-two test heifers and 48 put-and-take heifers were used in a randomised design in a 3 × 2 factorial arrangement [three herbage allowances (1.5, 2.0, and 2.5 kg of green dry matter/kg of bodyweight, and two supplementation levels (mineral mix or 0.3% bodyweight of a mineral-protein-energy supplement)], with two replicates per treatment (paddocks), to maintain the pre-established forage allowance. No significant difference was observed in the gain per hectare as a function of the herbage allowance, but 2.5 kg green dry matter/kg bodyweight provided the greatest average daily gain of bodyweight (0.605 kg/animal/day). The energy/protein supplementation provided the greatest average daily gain compared with animals fed only the mineral mix. The supplements in the diet of beef heifers fed at 0.3% of bodyweight increased bodyweight gains without compromising the gain per hectare at different herbage allowances.