Digestibilidade Aparente da Proteína Bruta e dos Componentes da Parede Celular de uma Ração Completa, com Bovinos de Diferentes Grupos Genéticos

Abstract

The digestibility of ether extract (EE), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HCEL) and cellulose (CEL) of a total ration was evaluated. The ration, composed by 44.3% Brachiaria hay, 55% concentrate and 0.7% mineral mixture, was fed to animals of different genetic groups (Gyr, Nellore, Guzera, Santa Gertrudis and Caracu), using total feces collection and internal marker (acid detergent lignin - ADL). The data were analyzed in a completely randomized design, with three replications for genetic group, with analysis of variance for both technique and correlation analysis between them. There were no differences among genetic groups for digestibility of EE, CP, NDF, ADF, HCEL and CEL using total feces collection and ADL, with averages of 44.28% and 40.38%; 52.46% and 49.51%; 57.04% and 54.25%; 37.71% and 34.04%; 71.66% and 69.68%; 48.27% and 45.20%, respectively. Digestibility for CP, ADF and CEL did not show correlation. ADL was efficient to estimate digestibility, and nutrients were used in a similar way for the different genetic groups.