Effect of low protein diets supplemented with threonine on growth performance and nutrient apparent digestibility of Hainan pigs.

The experiment was conducted to study the effect of low protein diets supplemented with threonine on growth performance and feed digestibility of Hainan pigs. 64 Hainan pigs with the body weight of (55.31±3.09) kg were randomly divided into four groups, with four replicates in each group and four pigs in each replicate. The pigs in control group were fed with 16% crude protein level and 0.6% threonine level. The crude protein level of trial groups I, group II and group III was 14%, and the supplemental level of threonine was 0.6%, 0.8% and 1.0%, respectively. The experimental group was balanced with lysine, tryptophan, valine and arginine. The experiment lasted for 35 d. The results showed that adding threonine to low protein diet to 0.8% could restore the production performance of Hainan pigs to normal diet level (P>0.05). Low protein diet supplemented with threonine significantly increased the apparent digestibility of CP and P of Hainan pigs (P<0.05), and the apparent digestibility of CP of pigs in group III and group II were 13.46% and 12.03% higher than that in control group. Compared with control group, the apparent digestibility of phosphorus of pigs in group II was increased by 9.02%, and that in group III was increased by 8.00% (P<0.05). The experiment indicates that dietary crude protein reduced to 14% and threonine supplemented to 0.8% can improve feed utilization rate without reducing growth rate of Hainan pigs, and it was suggested to be used in production of Hainan pigs. [ABSTRACT FROM AUTHOR]