Net energy for 60 to 120 kg pigs fed low crude protein diets

Two experiments were conducted to determine the effects of dietary net energy content (NE) on performance and carcass traits of finishing barrows fed low crude protein (CP) diets. Pigs (60.0 +/- 2.41 kg, Exp. 1; 90.0 +/- 2.96 kg, Exp. 2) were allotted in randomized design to four dietary treatments. Exp. 1 had nine pens treatment(-1) and Exp. 2 had eight pens treatment(-1), with two pigs in all pens. The treatments were as follows: 179 g kg(-1) CP and 2589 kcal NE kg(-1), 134 g kg(-1) CP and 2631 kcal NE kg(-1), 134 g kg(-1) CP and 2589 kcal NE kg(-1), and 134 g kg(-1) and 2589 kcal NE kg(-1) (pair-feeding to 179 g kg(-1) CP and 2589 kcal NE kg(-1)) in Exp. 1 and 166 g kg(-1) and 2604 kcal NE kg(-1), 123 g kg(-1) CP and 2645 kcal NE kg(-1), 123 g kg(-1) CP and 2604 kcal NE kg(-1), and 12.34% CP and 2604 kcal NE kg(-1) (pair feeding to 166 g kg(-1) CP and 2604 kcal NE kg(-1)) in Exp. 2. In Exp. 1, there was no effect of CP or NE on any performance and carcass traits evaluated. In Exp. 2, the greatest result of average daily gain was obtained with 123 g kg(-1) CP and 2645 kcal NE kg(-1). There was no effect of CP or NE on any other performance and carcass traits evaluated. For 60 to 90 kg barrows, reducing the CP of the diet from 179 g kg(-1) to 134 g kg(-1), adjusting or not adjusting the NE content of the diets with 134 g kg(-1) CP does not compromise performance or carcass traits. For 90 to 110 kg barrows, reducing the CP of the diet from 16.62 to 123 g kg(-1), while maintaining the same NE content (2604 kcal kg(-1)) of the diet with 166 g kg(-1) CP does not compromise performance or carcass traits.