Effect of sodium arsenite with or without methionine or methionine betaine on reproductive and immune status of pullets

An experiment was conducted to find out the effect of sodium arsenite with or without extra supplementation of methionine or methionine-betaine combination on reproductive performance and immune status of layer chicken. Rhode Island Red. (RIR) pullets (120; 16 weeks old) randomly distributed in four equal groups (each having 3 replicates with 10 birds each (9 hens, 1 cock) were offered either control (C), or C supplemented with either 1/20^th LD₅₀ arsenic (LD₅₀As) through water (T₁), 1/20^th LD₅₀ As through water with 50% more methionine (i.e. 50g methionine/100 kg of feed) than requirement through feed (T₂), 1/20^th LD₅₀ As through water and 25% more methionine than requirement and betaine (substitute of 25% extra methionine) through feed (T₃). Fertility, hatchability rate of eggs and embryo mortality decreased in As treated groups than control group. But layer chicken with extra supplementation of methionine or methionine-betaine combination showed increased fertility, hatchability rate of eggs with reduced embryo mortality and congenital defects than T₁ group. Chicks weight after hatching showed significant (P<0.05) variation among the groups. Immune status of different groups of bird showed significant (P<0.01) difference.