This experiment was carried with Japanese quails in the egg production phase with the objective of determining the requirements of digestible methionine + cystine (M+C) for higher production and egg quality. A total of 240 Japanese quails were distributed in a randomized complete block design. The basal diet was supplemented with different DL-methionine levels, corresponding to digestible methionine + cystine levels of 0.55, 0.61, 0.67, 0.73 and 0.79%. The characteristics analyzed were feed intake (g/quail/day), egg production (%), egg weight (g), egg mass (g/quail/day), feed conversion (dozen eggs/egg mass and kg feed/dozen eggs), egg shell (% and g), albumen (% and g), yolk (% and g) and specific gravity (g/cm³). The digestible M+C level for Japanese quails was 0.696% in the diet, corresponding to a daily intake of 186.7 mg/quail.
egg production; egg quality; sulfur amino acids
