Effect of energy concentration on growth performance and carcass quality of Iberian pigs reared under intensive conditions

Abstract

In total, 192 Iberian pigs were used to investigate the effects of net energy (NE) concentration of the diet on growth performance and carcass quality of castrated females (CF) and castrated males (CM). From 30 to 112 kg body weight (BW), three diets were formulated with similar digestible amino acid content per kcal of NE but differing in energy concentration (2,045, 2,175 and 2,305 kcal NE kg-1 from 30 to 81 kg BW and 2,175, 2,305 and 2,445 kcal NE kg-1 from 81 to 112 kg BW). From 112 kg to slaughter (148 kg BW), all pigs received a common finisher diet. Each treatment was replicated eight times and the experimental unit was a pen with four pigs. A decrease in NE concentration of the diet increased feed intake (p<0.05) and tended to impaired feed conversion ratio (p<0.10), whereas carcass and meat quality traits were not affected. Castrated males ate more feed and grew faster but had less fat thickness at the gluteus medius muscle than CF (p<0.05). However, no differences in carcass and meat quality traits between genders were detected. We conclude that a reduction in NE content of the grower diets did not affect growth rate and therefore, it not a valuable alternative to avoid excess of BW at slaughter in Iberian pigs reared under intensive management conditions. Also, both genders can be used for the production of high quality carcasses destined to the dry-cured industry.