Lysine concentration in dietary protein affects performance and pattern of nutrient retention of weaned Iberian piglets

Abstract

The amino acid composition of dietary protein, specifically the essential amino acid composition, is a key factor that affects the efficiency of use of dietary protein and, therefore, growth and protein retention. The balance among essential amino acid for maintenance and production functions has been established in pigs, with some variations according to the physiological state of the animal (BSAS, 2003). Pig genotype is one the factors that might influence such balance, although limited information is available in the literature concerning this issue. The Iberian pig is an obese, slow-growing breed. In previous work we have shown that Iberian pig requirements for total protein differ markedly from those of pigs of conventional genotypes (Nieto et al., 2012), although dietary protein was formulated following the amino acid pattern (g amino acid/kg crude protein) established for conventional pigs. The present work aimed at establishing the dietary lysine (Lys) requirements (g Lys/kg crude protein) for optimum performance of post-weaned Iberian piglets.