A note on inbreeding effect on productive and reproductive traits in laying hens

Inbreeding rate and effects on production (body weight, age at first egg, egg weight), and reproduction (per cent of eggs fertilized, per cent of eggs hatched as related to eggs set) traits were evaluated in 9194 layers belonging to two strains. The individual inbreeding coefficients were calculated using Wright’s formula from available performance records across nine generations. The inbreeding effects (including linear covariable) were estimated by derivative-free restricted maximum likelihood algorithm under an animal model. In general, the inbreeding level appeared relatively low in both populations. The inbreeding depressions for the traits studied (except per cent of eggs fertilized) were found low. The heritability estimates of productive and reproductive traits corresponded with those reported in literature.