Determinação do nível de lisina na fase inicial-I do crescimento de suínos, através da composição química e deposição de tecidos

Twenty commercial hybrids piglets, barrows and females were sampled to carry out a performance experiment and to determine the better lysine level based on chemical composition of the body fractions and deposition rates. The lysine levels were 0.85, 0.95, 1.05, 1.15 and 1.25%. It was not observed significant effects on the chemical composition of viscera and blood, characterising the independence of the lysine levels on the characteristics. There was positive response with increasing lysine levels upon carcass protein, characterising better efficiency in the utilisation and destination of the aminoacid for protein synthesis of skeletal muscles. It was not observed interference of dietary lysine levels in the daily rates of protein and lipid deposition of the carcass; and on the body chemical composition. With the increasing of lysine levels it was observed a linear reduction in the lipid daily deposition on the empty body. The body lipid reduction, as a response to the increase of dietary lysine levels indicated the efficiency of the aminoacid utilisation. From the results of body composition and deposition, it was concluded that the lysine levels may not be less than 1.25% for piglets from 6.0 to 11.6 kg, suggesting new studies with lysine levels above 1.25%.