ABSTRACT
Two assays were performed to estimate digestible threonine-lysine (Threo-Lys) ratio for female meat-type quails between 21 and 28 days old and between 28 and 35 days old. Experimental design was totally randomized. The first assay comprised 440 quails distributed into 5 treatments, 8 replications and 11 fowls per cage. The second assay comprised 280 quails distributed into 5 treatments, 8 replications and 7 fowls per cage. Five digestible Threo: Lys ratios were evaluated (0.66, 0.71, 0.76, 0.81 and 0.86). Performance, carcass and cut yield, chemical composition of carcass and nitrogen balance were evaluated. There was an improvement (P<0.05) in feed conversion and increase in feed intake due to ratios of digestible Threo: Lys between 21 and 28 and between 29 and 35 days olds, respectively. At 35 days old, there was a better (P<0.05) carcass yield and a negative nitrogen balance for Threo: Lys analyzed. A ratio of 0.86 may be recommended for digestible Threo: Lys as the best for feed conversion and carcass yield for female meat-type quails between 21 and 28 and between 28 and 35 days.
Keywords:
essential amino acids; ideal protein; limiting amino acid; mucin; productive performance