The objective ofthis work was to determine digestible sulfurous amino acids levels to establishthe ideal methionine+cystine:lysine relationships in meals of light-weight layinghens in the period from 24 to 40 weeks of age. It was used 216 Hy-Line W36 birdsdistributed in a randomized block design with 6 levels each one with 6 repetitionsand 6 birds per experimental unit. The digestible sulfurous amino acids levelswere obtained from a basal diet with low levels of digestible metionin+cistine(0.65%) supplemented with 0.00; 0.05; 0.10; 0.15; 0.20 and 0.25% of DL-methionine(99.2%) to provide a relationship methionine+cystine:lysine of 84, 91, 97, 104,110 and 117%. The experimental period lasted 16 weeks and it was subdividedin 4 subperiods of collection of the eggs, each one corresponding to 28 days.Levels of digestible methionine+cistine affected egg production and lysine utilizationefficiency per total egg production, reaching a plateau in 0.811 and 0.772%of digestible methionine+cistine, respectively. The digestible methionine+cystinelevel considered as a requirement for light-weight laying hens in the periodfrom 24 to 40 weeks of age is of 0.772%, corresponding to digestible methionine+cystineconsumption of 682 mg/hen/day, and the relationship methionine+cystine:lysineof 100%.
