Evaluation of the effects of supplementation with threonine in broilers from 0 to 3 weeks of age

Abstract

In order to evaluate the effects of threonine supplementation of diets differing in protein and metabolizable energy content, three experiments were carried out using broiler chicks of 0 to 3 weeks of age raised in electrically heated batteries. Body weight gain, feed consumption and feed efficiency were recorded. In experiment one, a basal diet that contained 0.70% threonine was used and was supplemented with four levels of threonine (0, 0.05, 0.10 and 0.15%) at two levels of metabolizable energy (3.1 and 3.2 Mcal ME/kg). No significant differences were observed among treatments due to either energy or threonine supplementation. In experiment two, sorghum-peanut-corn gluten meal diets of 20 and 22% protein were supplemented with threonine at the same levels used in the previous experiment. The results indicated no difference due to protein (P> .05) but threonine supplementation had significant effects on gain, feed consumption and feed efficiency. The chicks fed the lowest level of threonine (0.70%) gained less and also consumed less feed (P<.01). Birds with the highest level of threonine had the lowest efficiency (P< .01). In the third experiment, sorghum-soybean diets with two levels of protein (20 and 22%) were supplemented with five levels of threonine (0, 0.02, 0.05, 0.07 and 0.09%) for the 20% CP diet or four threonine levels (0, 0.02, 0.04 and 0.06%) for the 22% CP diets. No differences (P>.05) were observed among treatments.