Amino acid requirements of pigs. 2. Requirement for apparent digestible threonine of young pigs.

Abstract

In 6 trials with 460 pigs, initially about 19 kg the threonine requirement for growth between about 20 to 40 kg was investigated. To a negative control diet, containing crude protein 160 g and threonine 5.6 g/kg. L-threonine 0.0, 0.6, 1.2 and 1.8 g/kg, was added and compared with a positive control diet with crude protein 185 g/kg and threonine 6.8 g/kg. The negative control diet was supplemented with lysine, methionine, tryptophan, isoleucine, histidine and valine so that no other amino acids than threonine were limiting. The positive control diet was supplemented with lysine and methionine. The experimental diets were fed ad libitum as pellets. In 2 separate trials, the apparent faecal and ileal digestibility of the amino acids of the 2 control diets was estimated. The requirement for total threonine was 7.1 g/kg for maximum weight gain, and 7.4 g/kg for maximum efficiency of feed utilization in a diet containing net energy 2290 kcal/kg. These results correspond with 6.2 and 6.5 g/kg faecal digestible and 5.7 and 6.0 g/kg ileal digestible threonine, respectively. Pig performance on the negative control diet supplemented with the first limiting amino acids, was similar to that of the positive control diet. (Abstract retrieved from CAB Abstracts by CABI’s permission)