Efeitos do processamento de ração e da linhagem sobre os valores energéticos e desempenho de frangos de corte

Abstract

Two experiments were carried out in order to evaluate the effects of physical form of the rations, heat production and energy values of the rations (experiment I), performance and cuts yields of two lines of broilers (Cobb and Ross). The treatments were defined according to the lines, physical form of the rations and consume of the ration and were mash, pelleted and restricted pelleted (with equal consume of the mash ration). In the first experiment, were used 420 birds raised in metallic cages adapted for collection of the excreta. The statistical design was the split plot block in 3 x 2 (3 diets and 2 lines) factorial arrangements with 4 repetitions (periods) being the period considered the block. The digestibility of dry matter was not affected for the physical form of the ration. The pelletization enhanced the digestibility of the ether extract. The line affected the digestibility of the rations. The physical form of the ration and the line didn’t affect the heat production of the broilers. The utilization of pelleted rations improved the net energy values of the rations, independent of the line. In the second trial 900 day old broilers were raised in experimental poultry house from 1 to 45 days of age. The treatments were the same of the first trial. To evaluate the performance the statistical design was the complete randomized with 3 x 2 (3 diets and 2 lines) factorial arrangement with five repetitions, being 30 birds in each repetition. To evaluate the cuts yields the statistical design was the same with 30 birds for each treatment, being each bird considered one repetition. The peletization improved the weight gain of the broilers, independent of the line. The line didn’t influence the cuts yields evaluated. The peletization improved the net energy of the rations enhancing the broilers performance.