Optimizing energy, protein and amino acid needs in diet of starting and growing Aseel chicks

Two experiments were conducted to optimize dietary energy, protein and amino acid profile during 0–20 weeks of age. In first experiment, six diet formulated with two levels of energy (2700 and 2500 kcal ME/kg) each with three levels of protein (20, 18 and 16%), following 2 x3 factorial design were allotted to four replicated groups of 12 chicks each for 0–12 wk of age. In second experiment, female Aseel growing birds of 12 wk of age (n=120) were randomly distributed in to six dietary treatments with two levels of energy (2700 and 2500 kcal ME/kg) each with three levels of protein (16, 14 and 12%), following a 2 x 3 factorial design. Each diet was randomly offered to four replicated groups of 5 growing chicks from 12 to 20 wk of age. Higher (P<0.01)body weight gain and improved feed conversion ratio (FCR) were observed in chicks fed 2700 kcal ME/kg diet during 0–12 wk of age. Body weight gain of chicks fed 18 and 20% CP diet was higher (P<0.01) than those fed diets with 16% CP. Improved(P<0.01) FCR was recorded at 18 and 20% protein diets than in 16% protein diet. Body weight gain at 20 weeks of age differed (P<0.05) due to protein levels and values were higher at (14% CP) level. Feed intake, FCR and protein efficiency altered (P<0.05) due to energy level. The results revealed that the optimum dietary energy, protein and amino acid levels for 0–12 weeks of age of Aseel chicks were 2700 kcal ME/kg, 18% CP and 1.12% lysine, 0.50% methionine and 0.70% threonine, respectively. Whereas during 12–20 weeks of age, dietary energy level of 2700 kcal ME/kg with 14% CP, 0.66% lysine, 0.30% methionine and 0.54% threonine was found optimum.