This study was conducted to evaluate the effect of the diet supplementation on the heifers performance in finishing phase, maintained in a marandu grass pasture managed in intermittent grazing system during the rainy season. Twenty crossbreed (¼ Nelore, ¼ Santa Gertrudes, ½ Braunvieh) heifers with average initial body weight of 300 kg and 22 months old were used. The treatments consisted of two types of supplements: mineral (SM) ad libtum and energy protein supplementation (PES) provided 0.3% of the body weight daily. The evaluated variables were: animal performance and carcass traits measured by ultrasound each 28 days. Supplementation affected daily weight gain (P=0.057), 0.700 kg/day for supplemented animals against 0.587 kg/day for animals receiving salt-mineral. There were no supplementation effect on the loin eye area and depth of the Gluteus medius muscle. The other characteristics examined by the ultrasound technique did not differ according to the treatments. Protein and energy supplementation of the diet allows additional gains that reflected in increased deposition of muscle of heifers grazing marandu grass during the wet season.
Animal performance; tropical grass; grazing; ultrasound
