Effects of Threonine Supplementation in Low Protein Diet on Broilers Growth Performance and Biochemical Parameters

The present study was conducted to evaluate the effects of graded levels of threonine (Thr) on growth performance and biochemical parameters in broiler chickens. For this purpose, one-day-old 150 broiler chicks were kept in pens at Poultry Farm of the University of Agriculture, Faisalabad for 5 weeks. Chicks were divided into three treatments including T1 (control group), T2 (CP 1% less and Thr 10% extra) and T3 (CP 2% less and Thr 20% extra). Iso-caloric diets were formulated according to two phases as a starter (1–21 days) and finisher (22–35 days). Treatments were replicated into 5 subgroups having 10 chicks in each. Data collected were analyzed by analysis of variance technique under CRD. Chicks fed diet contained CP 1% less and Thr 10% extra had lower (P < 0.05) feed intake, improved (P < 0.05) weight gain and FCR than those fed diet containing CP 2% less and Thr 20% extra. Dressing percentage was higher (P < 0.05) in chicks fed a control diet. However, higher (P < 0.05) breast yield and lower (P < 0.05) production cost per kg live weight were recorded in birds fed diet contained CP 1% less and Thr 10% extra than other groups. Different treatments had no effect (P > 0.05) on relative organ weight. Chicks fed diets having reduced CP and increased Thr had no effect (P > 0.05) on blood parameters and liver enzymes activity. Based on these findings, it can be concluded that lowering CP by 1% and increasing Thr by 10% resulted in better growth performance, breast yield and economics efficiency than lowering CP by 2% and increasing Thr by 20%. © 2022 Friends Science Publishers