The objective of this work was to estimate the nutritional requirements of net and metabolizable energy of Nellore, Nellore-Angus and Nellore Simmental cattle, as well as the efficiency of utilization of metabolizable energy for gain and maintenance and efficiency of energy deposition in the form of protein and fat. It was used 69 animals (23 Nellore, 23 Nellore-Angus and 23 Nellore-Simmental): four animals from each genetic group (12 in total) were slaughtered before the beginning of the experiment as the […]

The objective of this work was to study the effect of dietary ME levels on the performance and the energy metabolism of male broilers on growing phase, from 22 to 43 days old. Two hundred and eighty-eight broilers were ramdomly assigned to three energy levels (3,050; 3,200 and 3,350 kcal/kg) and three feeding levels (ad libitum, 75% and 50% ad libitum), with four replicates of eight birds, to determine the energy maintenance requirements and the energy efficiency utilization. The method […]

Partial or total data, from several works, on nutritional requirements of bovine, were utilized. In all the experiments, the comparative slaughter technique was used, with the slaughter of a representative sample of the experimental animals at the beginning of the feeding period and the determination of the empty body composition. The fat, protein, energy, Ca, P, Mg, Na and K contents retained in the animal body of each breed group were estimated by regression equations of the logarithm of protein, […]