Digestible methionine + cysteine: lysine ratios for growing meat-type quails/Relacces de metionina + cisterna: lisina digestiveis para codornas de corte em crescimento

The objective was to estimate the most appropriate digestible methionine + cysteine:lysine ratios for growing meat-type quails (Coturnix coturnix) from 1 to 21 days of age. Quails were fed with a basal ration deficient in digestible methionine + cysteine, with five levels of DL-methionine, in substitution of glutamic acid and starch, resulting in digestible methionine + cysteine:lysine ratios of 0.61, 0.66, 0.71, 0.76 and 0.81. Feed and methionine + cysteine intake, body weight gain, feed conversion and uniformity were assessed. From 1 to 7 days, an increasing linear effect was observed for feed and methionine + cysteine intake, body weight gain, and uniformity, and a linear decrease for feed conversion. From 8 to 14 days, the 0.70 methionine + cysteine: lysine ratio was the best for feed intake and body weight gain, and for uniformity, the 0.75 methionine + cysteine:lysine ratio was the most appropriate. For methionine + cysteine intake and feed conversion, an increasing and decreasing linear adjustment was observed, respectively. From 15 to 21 days, an increasing linear effect was observed for feed and methionine + cysteine intake and body weight gain; a decreasing linear effect was observed for feed conversion. The 0.81 ratio was the most efficient for feed conversion during all evaluated experimental periods. In conclusion, the 0.81 dietary methionine + cysteine:lysine ratio is the most appropriate for meat-type quails during the first 21 days of age. Key words: Coturnix coturnix, ideal protein, performance, sulfur amino acids. O objetivo foi estimar as relacoes metionina + cisterna: lisina digestiveis mais apropriadas para a criacao de codornas de corte (Coturnix coturnix) de 1 a 21 dias de idade. As codornas foram alimentadas com uma racao basal deficiente em metionina + cisteina digestivel, com cinco niveis de DL-metionina, em substituicao ao acido glutamico e ao amido, resultando nas relacoes metionina + cisteina: lisina digestiveis de 0,61; 0,66; 0,71; 0,76 e 0,81. O consumo de racao, a ingestao de metionina + cisteina, o ganho de peso corporal, a conversao alimentar e a uniformidade foram avaliados. De 1 a 7 dias, um efeito linear crescente foi observado para consumo de racao e de metionina + cisteina, ganho de peso corporal e uniformidade, e reducao linear para conversao alimentar. De 8 a 14 dias, a relacao metionina cisteina: lisina de 0,70 foi melhor para consumo de racao e ganho de peso corporal, e para uniformidade, a relacao metionina + cis