Effects Of Feeding Density On Production Performance And Welfare Of Layers

In order to research the impact of different breeding density on the production performanceand welfare of laying hens,125011-week-old Hy-line Gray laying hens were randomlyallocated into5groups with the stocking density of900cm2,675cm2,540cm2,450cm2and380cm2perlayer respectively. All the hens were reared from11-week-old to50-week-old underthe same environment condition. This study was to explore the impact of stocking density onthe growth, the production performance and the welfare of laying hens.Firstly, we analysed the days to laying rate reached50%, the weight of18-week-old, theweight of20-week-old, the uniformity of the weight of20-week-old and the weight of ovaryand visceral of18-week-old and20-week-old. The resμlts showed that there was no significantdifference of the weight of the body, ovary, heart, liver and spleen between the groups at18-week-old.The weight of body of group A and B was higher than other groups significantly at20-week-old. The weight of the ovary of the group A was47.50g, which was higher than othergroups significantly at20-week-old. The weight of the spleen of group A and B was higher thanother groups significantly and there was no significant difference of the weight of the heart andliver between the groups at20-week-old.Secondly, we analysed the egg production, the weight of egg, egg qualities, the ratio of feedto egg and the mortality rate of layers from20-week-old to50-week-old. The resμlts showedthat the egg production was reduced gradually with the raising of the breeding density. Thebreeding density had no influence on the weight of egg and egg qualities. The mortality rate oflayers was raised gradually with the raising of the stocking density.Lastly, we analysed the levels of Ca, P, GLU, CH, CORT, IgM, IgG and IgA in the blood, theantibody titer of ND, H5and H9from20-week-old to40-week-old. Then we evaluate thewelfare condition of the feathers at50-week-old. The resμlts showed that the breeding densityhad definite influence on the blood index and the antibody titer. With the raising of the breedingdensity, the level of CORT and the levels of the stress were raised, the welfare condition of thefeathers was reduced.