Reevaluation of digestible amino acid requirements of male and female broilers based on different ideal amino acids ratios in starter period

An experiment was conducted to reevaluate the digestible amino acid (AA) requirements of broilers based on different ideal amino acid ratios for male and female broiler chicks during the starter period (1-14 days). A total of 720 one-day-old feather sexed male and female broiler chicks were equally distributed to 12 dietary treatments with 4 replications per treatment and 15 chicks per replication. AA requirements were estimated based on digestible Lys requirement of 1.22 and 1.20 percent for male and female respectively, and different ideal AA ratios including Illinois Ideal Chick Protein (IICP), CVB, Feedstuff, NRC, ROSS and RPAN (Rhone Poulenc Animal Nutrition). Feed intake, body weight gain (BWG), and humeral immunity responses were measured for each pen at day 14 post hatch and feed:gain was calculated. Results of this study show that broiler chicks fed IICP diet had lower feed intake while broiler chicks fed ROSS and RPAN diets had lower BWG and feed:gain compared to other ideal amino acid profiles. When comparisons were made among chicks fed diets formulated with different ideal amino acid ratios, the most significant (p<0.05) performance improvements were observed by Feedstuff and CVB ratios. Feedstuff ratio had highest body weight gain and a better feed:gain (p<0.05) relative to all the other ratios for both genders. Digestible Lys, Met, Met+Cys, Thr, Ile, Arg, Trp, Leu and Val requirements for male and female broiler were estimated based on Feedstuff ratio to be 1.22, 0.54, 0.85, 0.73, 0.85, 1.34, 0.24, 1.62, 0.93 and 1.20, 0.53, 0.84, 0.72, 0.83, 1.32, 0.24, 1.60, 0.92 in starter period, respectively.