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

摘要

A study was conducted involving day-old Kadaknath chicks (n=288) to evaluate their optimum dietary energy, protein and amino acid levels for 0-20 weeks of age. Six dietary treatments with two levels of energy (2700 kcal and 2500 kcal ME/kg) each withthree levels of protein (20, 18 and 16%), following 2 x3 factorial design, were formulated. Each of such diet was randomly allotted to 4 replicated groups of 12 chicks each kept in battery brooder cages for 0-12 weeks of age. In second experiment femaleKadaknath growing chicks 12 wks of age (n=120) were randomly re-distributed to six dietary treatments with two levels of energy (2700 kcal and 2500 kcal ME/kg) each with three levels of protein (16, 14 and 12%) following a 2 x 3 factorial design were formulated and each of such diet was randomly offered to 4 replicated groups of 5 growing chicks each kept in growing cages from 12 to 20 wks of age. Results indicated that body weight gain of chicks (0-12wk) fed 2700 kcal ME/kg diet was significantly higher (P<0.01) than those fed diets with 2500 kcal ME/kg. Feed conversion ratio was better in 2700 kcal ME/kg in comparison to those fed 2500 kcal ME/kg. Body weight gain of chicks (0-12 wks) fed 18 and 20% CP was significantly higher in comparison to chicksthose fed 16% CP. The gain in body weight during 12-20 weeks of age remained similar in all the protein levels and protein x energy interaction but significantly higher gain in body weight was recorded at low energy than higher energy diet. Feed intakewas recorded significantly higher (P<0.001) at low energy than high energy diet but feed conversion efficiency remained similar due to different energy levels. The feed conversion efficiency and ME efficiency were significantly lower in low protein dietwhereas protein efficiency was comparable in different protein levels in diet. The results revealed that the optimum dietary energy, protein and amino acid levels for 0-12 wks age Kadaknath 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 2500 kcal ME/kg with 14% CP, 0.66% lysine, 0.30% methionine and 0.54% threonine was optimum.