The effects of feed restrictions in rearing period on growing and laying performances of white and brown layer hybrids in different adult body weights

Abstract

This study was conducted to determine the effects of feed restriction in the rearing period on growth and laying performances of layers. Three egg type local commercial lines differing in body size (heavy brown, heavy medium brown and light white layer) were used in the experiment. Chicks were reared on litter pens for 17 weeks and than transferred to laying battery cages. All birds were fed a standard starter diet I to S weeks of age and 9 to 12 weeks of age were fed a growing diet and 13 to 17 weeks of age were fed a developer diet. Chicks were fed ad libitum in the first 8 weeks, than ad libitum, one day and two days teed restriction in a week applied to three each replicates of genotype. Birds were fed ad libitum a standard laying diets in the laying period. Two days feed restriction groups consumed less feed (p<0-05) in the rearing period, but there was no significant differences among the body weights and chick uniformity. Also, two days feed restricted groups had lower viability in all genotypes (p<0.01), The effect of feed restriction in the rearing period on egg production was found significant, bur sexual maturity ages were delayed by the feed restriction (p<00l). Feed consumption of laying period were found significantly different (p<00l) and restricted groups cons Limed more feed than the control groups. Shell thickness is the only egg quality trait which was affected from feed restriction (p<0.0l). Also, feather scone was affected by feed restriction (p<0.01). © 2009 Academic Journals Inc.