Total versus digestible amino acid requirements for growth and nutrientutilization of naked neck broilers during finishing phase

Abstract

Not AvBhanja, S.K. and Mandal, A.B. 2019. Total versus digestible amino acid requirements for growth and nutrient utilization of naked neckbroilers during finishing phase. Indian Journal of Poultry Science, 54(3): 233-238.A study was conducted to compare the performance of Naked neck broilers (n=288) when fed 12 isocaloric diets (2×3×2 factorialdesign) formulated on either total or digestible amino acids basis (2 variables), three levels of amino acids (115, 100 and 85 % of NRC,1994 requirements) and with (FM) or without animal (VM) protein source (2 variables) during 4-6 wks period. The 6th wk body weight,4-6 wk body weight gain and FCR did not differ due to total or digestible amino acids basis. Better 6th wk BW, 4-6 wk BWG and FCRwere recorded in groups fed high (115%) and medium (100%) levels of amino acids. However, higher feed intake was recorded in thelower AA level. Efficiency of ME utilization was better (P<0.001) in high and medium AA diets. Whereas, better CP efficiency wasrecorded in low (85%) AA diets. Diets having higher levels of AA recorded increased N retention and decrease in N loss in birds. LowerN loss (P<0.001) was recorded in FM based diet than all VM diet. It may be concluded that the broilers fed diets formulated on digestibleAA basis had similar performance, but better N-retention and lower N-loss than those fed diets of total amino acid groups. The optimumcritical AA requirement for naked neck broiler during finisher phase might be 100% amino acid level of NRC (1994). Animal or vegetableprotein source diets did not alter performance in the broiler during finishing periodailable