DESEMPENHO E CARCACTERÍSTICAS DE CARCAÇA DE NOVILHAS CRUZADAS DE TRÊS GRUPOS GENÉTICOS RECEBENDO DIETAS À BASE DE SILAGEM DE SORGO E MILHO

Abstract

This study aimed to evaluate the carcass quality and the weight gain of crossbred heifers from three genetic groups, fed corn or sorghum silage. Eighteen heifers, 6 originated from crossbreds between ½ Holstein/Gir cows and Gir bulls (TGG: 3/4 Gir and ¼ Holstein), six from crossbreds between ½ Holstein/Gir cows and Nellore bulls (TNG: ½ Nellore, ¼ Gir and ¼ Holstein), and six from crossbreds between ½ Holstein/Gir cows and Guzera bulls (TUG: ½ Guzera, ¼ Gir and ¼ Holstein). The animals were distributed in a completely randomized design, in a 3 x 2 factorial arrangement, with three genetic groups. Daily weight gain, intake, and feed conversion were estimated. At the beginning and end of the experiment, the ribeye area (REA), the subcutaneous fat between 12th and 13th ribs (SFBR), and the subcutaneous fat under the Biceps femoris muscle (SFBFM) were obtained by ultrasound. The genetic groups did not influence the variables evaluated. Corn silage diets provided a higher performance than the sorghum silage diets.

Keywords

• Carcass quality
• crossbred animals
• roughage fraction of the diet
• weight gain.