Influence of L-threonine in reduced dietary crude protein levels on growth and economic indices in broilers

The present study was aimed to investigate the effect of reduced dietary crude protein (CP) supplemented with L-threonine on economic feasibility of in commercial broiler diets. A total of 480 broiler chicks were randomly assigned to 4 dietary treatments following completely randomized design, each treatment had six replications of 20 birds each. The control dietary formulation was prepared to meet requirement of nutrients and amino acids. The dietary CP was reduced by 1, 2 and 3 per cent unit to the standard recommendation in other 3 treatments. The diets with reduced CP level were supplemented with synthetic threonine. From the study, it was found that the economic indices viz., cost of production per bird, cost of production per kilogram live body weight, net return per bird, net return per kilogram live body weight, performance index score (PIS) and economic index score (EIS) were significantly influenced by the supplementation of L-threonine in reduced dietary CP levels. The lowest cost of production per bird was recorded in birds fed with 3per cent crude protein reduced diet, where as the lower cost of production per kilogram live body weight was recorded in birds fed with control and 1 per cent crude protein reduced diets. Net returns per bird, net returns per kg live weight, PIS and EIS were better in birds fed with control and 1 per cent crude protein reduced diets. Up to one percent unit crude protein could be lowered at all growing phases of commercial broiler birds safely as it was economical.