digestible lysine requirement of arian male and female broiler chicks during six to twenty-one days of age

an experiment was conducted to determine the dietary digestible lysine requirement of male and female broiler chickens (arian) during the period from 6 to 21 days post-hatching. an amino acid-fortified basal diet containing corn and soybean meal as intact protein sources provided 20 % cp, and 3200 kcal amen / kg. in this experiment 150 male and 150 female chicks were allocated on the basis of bw to 12 treatments in a factorial arrangement (two sexes at six digestible lysine levels) with five replications of five chicks each in a completely randomized design (crd). the digestible lysine levels fed were 0.85, 0.95, 1.05, 1.15, 1.25 and 1.35%. the growth rate and feed efficiency of birds fed the basal diet fortified with a surfeit level of l-lysine-hcl were equal to those of birds fed a corn-soybean meal positive control diet. average body-weight gain (abwg) and gain: feed (gf) responded quadratically (p