Performance comparation between Nellore and crossbreed Nellore- Rubia Galega in feedlot system

Abstract

The use of feedlots to carcass termination in beef cattle have been increase in the Brazil, in addition with de crossbreed systems aiming increase the productive efficiency of animals in this system. The aim of this study was to compare the daily average weight gain performance, carcass yield, alimentary conversion and the biological efficiency of Nellore steers and the crossbreed Nelore-RubiaGallega kept in feedlot. It was used 276 bovines, being 140 of Nellore breed and 136 crossbreed with age ranging from 21 to 24 months. The animals were divided in collective installations according to the genetic group, kept 87 days in the feedlot. The diet used had high concentrated, exception the diet of the adaptation period. The statistical analysis were carried out by SAS - Statistical Analysis System and the average of initial weight, daily average gain and final weight were compared by the t test (p<0.01). The carcass yield was determined by the relationship between the weight of the empty body of the hot carcass by the final weight. The alimentary conversion was calculated by Kg of dry matter intake divided by the kg of gain. The biological efficiency was measured by kg of dry matter intake divided by the arrobas of carcass produced. The daily average gain, average final weight and carcass yield of Nellore-RubiaGallega animals were superior than the Nellore ones (p<0.01). Considering the alimentary conversion, the crossbred animals did intake 1.39 kg of dry matter less for each kg of weight gain. Considering the biological efficiency, for each arroba produced the Nellore animals had been consumed 37.09 kg of dry matter more than the crossbreed ones. The utilization of animals with Rubia-Gallega genetic in crossbreed systems with Nellore show improvement in the parameters evaluated.