With the objective to establish the nutritional requirement of threonine for light and semi-heavy laying hens in the period from 34 to 50 weeks old, 580 laying hens (half Lohmann and half Lohmann Brown) submitted to a basal ration containing 2.850 kcal ME/kg, 14.0% CP, supplemented of five levels (0.00, 0.035, 0.07, 0.105, and 0.140%) of L-threonine, in order to provide 0.410, 0.445, 0.480, 0.515, and 0.550% of digestible threonine in the rations. A 5 x 2 (threonine level and […]