Interaction of dietary energy and critical amino acids on growth performance and carcass yield of multicolored broiler chickens
S. K. BHANJA AND A B. MANDAL
Central Avian Research Institute, Izatnagar - 243 122
An experiment was conducted in winter months with multicolored broiler chickens (n=342) involving three levels of energy (3200, 3000 and 2800 kcal/kg), three levels of AA (115,100 and 85 % of NRC, 1994) each either as total or digestible in a 3 x 3 x 2 factorial design to assess optimum energy to AA ratio for growth and meat yield during 0-42 days of age. Body weight and gain (0-42 day) were higher (P<0.0001) at high AA and high-energy diet (1491, 1448 g) than low AA and low or high-energy diet (1023, 980 g). Feed intake did not vary with levels of AA and energy. Better FCR and ME efficiency (P<0.0001) were recorded in diets formulated with digestible AA, higher AA level and lower energy. High AA and high ME diet had FCR of 2.01 as compared to 2.65 in low AA and low ME diet. Lower expenditure on feed per kg gain was recorded in lower AA and energy diets. Significant AA level x ME interaction was observed for growth parameters viz. gain, feed intake, feed conversion energy efficiency and cost of production. Dressing yield of the bird was significantly higher in both high and low AA diets and least affected by dietary energy levels. The abdominal fat deposition was higher (3.37%) in high energy and high AA diet than low AA and low energy diet (1.60%). However, medium level of energy with high AA had also lower abdominal fat deposition (1.62%). Breast yield (P<0.05) and thigh yield (P<0.06) were higher in high AA diet, but the dietary energy levels had no effect on those yields. It may concluded that medium amino acid levels as that of NRC, 1994 and medium energy, 3000 kcal ME / kg diet may be economical for better growth and meat production.