The objectiveof this work is to determine the nutritional requirement of digestible threoninefor brown-egg laying hens between 79 to 95 weeks of age. For this experiment,180 commercial Lohmann Brown laying hens were used, distributed in five digestiblethreonine levels (0.380; 0.413; 0.446; 0.479 and 0.512%), each one with sixreplicates and six hens/replicate. It was observed a quadratic effect of threoninelevels on the feed intake, egg mass conversions, egg dozen conversions, eggproduction, egg weight, and egg mass. The digestible threonine intake increasedlinearly in function of diet threonine levels. It was not observed effect ofdiet threonine levels for weight gain, yolk index, albumen index, shell percentage,yolk percentage and albumen percentage, except for the Haugh units, which increasedin a quadratic way according to digestible threonine levels in the feed. Regardedto the food conversion per egg dozen, the requirement of digestible threoninefor commercial hens in the period between 79 to 95 weeks of age is 0.467%, whichcorresponds to an intake of 462 mg threonine/hen/day.
