Optimum Protein and Metabolizable Energy Levels in Royal Project Black-bone Chicken Diets During 11-16 Weeks of Age

Abstract

A total of 336 heads 10 weeks old Royal Project Black-bone (RPBB) chicken were randomly allotted into 4 groups of 3 replicates each (12 male and 16 female/rep.) according to a 2x2 factorial arrangement in CRD. They were fed with diet containing 2 CP levels, i.e. 17% vs. 15% and 2 ME levels (3.2 vs. 2.9 kcal/g) for 6 weeks. The results showed no significant interaction between CP and ME levels (P>0.05). When each factor was taken into consideration, it was found that different CP level had no significant effects (P>0.05) on body weight gain, ADG, feed intake, FCR and mortality rate. Chickens fed low ME level (2.9 kcal/g) consumed significantly more feed (P<0.01; 2.72 vs. 2.60 kg) thus gave significantly (P<0.05) higher body weight gain (0.61 vs. 0.58 kg) and ADG (14.58 vs. 13.56 g) than the high ME level (3.2 kcal/g). However no significant effect (P>0.05) was found on FCR and mortality rate. When each treatment was taken into consideration, it revealed that chicken consumed diet 2 (17% CP, 2.9 kcal ME/g) had significantly better performances than diets 1, 3 and 4 (P<0.05), i.e. higher body weight (0.64 vs. 0.57, 0.56 and 0.59 kg); ADG 15.15 vs. 13.68, 13.44 and 14.00 g) and lower FCR (4.34 vs. 4.51, 4.65 and 4.57) as well as lower feed cost per gain (50.74 vs. 58.41, 56.84 and 50.91 Baht/kg BW gain, respectively). It might be due to the higher feed intake (65.63 vs. 61.58, 62.30 and 63.97 g/d; P<0.05), thus caused higher nutrient intake, i.e. CP (11.17 vs. 10.47, 9.36 and 9.59 g/d; P<0.05). Therefore, it can be concluded that the optimum diet for 11-16 weeks old RPBB chicken should contain 17% CP, 2.9 kcal ME/g.