Effect of egg size and lines on hatching performance of chicks from broiler breeders under selection

The study was conducted with the objective of evaluating the effect of egg size (small, medium and large) and lines on egg and hatch weight, fertility, hatchability, embryonic mortality and infertile eggs of broiler breeders under selection. A total of 120 broiler chicks were hatched from three different egg sizes (40 chicks per egg size as indicated) from breeder parents at 40 weeks of age. The broiler breeders were mated in a ratio of 1:6. Data obtained were subjected to analysis of variance in a complete randomized design. The result showed that significant (p<0.05) egg weight loss in incubator were recorded with the large egg size group having the minimum loss of 10.85%. The hatch weight was significant (p<0.05) and increased from the small to the large (36.24, 36.73 and 40.22g) egg size group. Line had significant effect (p<0.05) only on the medium egg size: egg weight (sire = 57.50g; dam = 55.00g) and hatch weights (sire = 39.71g; dam = 36.10g). The fertility (94.02, 93.01 and 78.01%), hatchability (87.42, 88.20 and 62.41%) and embryonic mortality (6.58, 9.80 and 15.6%) had significant (p<0.05) differences with the small egg size group performing better excluding the average egg weight, which was then followed closely by medium egg size group. It can be concluded that for higher hatch weight target, the large egg size should be selected but for the purpose of better fertility and hatchability, the medium and small egg sizes should be selected.