Avaliação da restrição alimentar em bovinos da raça Sindi em crescimento

Abstract

This study aimed to determine the different levels of feed restriction effect on performance, carcass, nitrogen balance and microbial protein synthesis in Red Sindhi cattle breed. The experiment was conducted at the Federal University of Viçosa, with 32 unneutered male bulls divided into four feed restriction levels (0, 15, 30 and 45%) in a completely randomized design. The dry matter intake reduction, promoted by increased restriction resulted in a decrease in the consumption of nutrients affecting the performance and some quantitative carcass traits except yield percentage (hot and cold) and loin eye area. Happened a linear decrease (P <0,05) in weight of retail cuts, however, was not observed (P> 0,05) change in the proportions of them in relation to the half carcass weight. Significant quadratic effect of restriction level on body weight end (WCF), empty body weight (EBW), total weight gain (TWG), average daily gain (ADG), gain of empty body weight (EBW) and efficiency feed (EA), from 0.5 to 7.0% restriction. Happened a linear increase (P <0,05) in the muscle proportion and linear decrease (P <0,05) in the proportion of carcass fat, with increasing level of restriction. The restriction promoted a reduction in nitrogen excretion to the environment, and increase efficiency in the use of recycled nitrogen by animals. Moderate restriction levels can be applied on the male Sindi termination without compromising performance, generating a 41% difference in the profit margin, compared to the level of 15% restriction to the group fed ad libitum.