One hundred and sixty-eight Bovan Nera layers (average 1.98 kg) that had been in lay for 10 months were used to evaluate the effect of methionine, lysine and/ or vitamin C (Ascorbic acid) supplementation on egg production, external and internal egg quality characteristics of layers in the Humid Tropics. The experiment, which was in a completely randomized design (CRD), had seven treatments each replicated three times. There were 8 layers per replicate. The experimental diet was a 16% CP and 11.68 MJ kg-1 layer mash supplemented with either 0.03% vitamin C (VitC), 0.1% methionine (Me), 0.1% lysine (Li), 0.1% methionine + 0.03% vitamin C (ViC-Me), 0.1% lysine + 0.03% vitamin C (VitC-Li) or 0.1% methionine + 0.1% lysine (Mi-Li). The control diet (Ctl) had no methionine, lysine and/ or vitamin C supplementation.
The study lasted 5 months (November - March). Results showed that the supplementation of the layer diets with methionine, lysine and/ or vitamin C did not significantly influence egg production, external and internal egg quality characteristics of the layers.
Therefore, it may not be advantageous to supplement the diet of old layers with methionine, lysine and/ or vitamin C.