Influence of net energy content of the diets on productive performance and carcass merit of gilts, boars and immunocastrated males slaughtered at 120 kg BW

In total, 540 crossbred pigs with an initial body weight of 28.5 kg were used to investigate the effects of the net energy (NE) content (2.29, 2.33, 2.37, 2.41 and 2.45 Mcal/kg) of the diet on growth performance and carcass and meat quality traits of gilts, boars and immunocastrated males (IMC). An increase in dietary NE increased NE intake and decreased feed conversion ratio linearly. The IMC pigs showed greater feed intake and average daily gain than gilts and boars. Backfat depth increased and chilled and trimmed ham yield decreased, as the dietary NE increased. Backfat depth was greater for gilts and IMC than for boars. Also, gilts had greater carcass and loin yields than boars and IMC. Diets with the greater NE content were more appropriate for the production of heavy pigs. However, the economic interest of this practice needs further assessment. (C) 2014 Elsevier Ltd. All rights reserved.