An experiment was conducted to determine the digestible amino acids requirements of broilers based on different ideal amino acid ratios for male and female broiler chicks during finisher period. Experimental period began at day 29 and lasted in 42 d of age. A total of 720 male and female broiler chicks were equally distributed to 12 dietary treatments with 15 birds per pen and 4 pens per treatment. They were housed in a factorial arrangement of main factors (amino acid ratios and sex) in a completely randomized design. AA requirements were estimated by using digestible Lys requirement of 1.04 and 0.98 percent for male and female, and different ideal AA ratios including IICP, CVB, Feedstuff, NRC, ROSS and RPAN. Feed intake, weight gain and humeral immunity response were measured for each pen at day 42 and then feed:gain was calculated. Results of this study show that broiler chicks fed CVB had lower performance. Broiler chicks fed NRC and RPAN diets had lower feed: gain and better immune response (p<0.05) relative to all the other ratios for both sexes. 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 RPAN ratio. Digestible Lys, Met, Met+Cys, Thr, Ile, Arg, Trp, Leu and Val requirements for male and female broiler were 1.04, 0.538, 0.842, 0.696, 0.793, 1.255, 0.223, 1.553, 0.884 and 0.984, 0.504, 0.797, 0.659, 0.744, 1.175, 0.209, 1.493, 0.836 in finisher period, respectively.
