Quality of eggs from pasture rearing layers of different genotypes

Abstract

The comparison of physical quality properties of table eggs of commercial hybrid Tetra SL and two native indigenous breeds of hens, Banat Naked Neck and Svrljig hen, was performed in conditions of alternative production in the pasture system in portable cages without the floor. The experiment was conducted during the vegetation period, at the age of hens of 53-57 weeks. In order to produce good quality eggs, the diet was designed with a complete mixture based on maize and soybean. In addition, constant availability of pastures was ensured. Egg sampling was performed in the morning and the initial egg quality was examined based on egg weight, shape index, egg white, egg yolk and shell quality parameters. Layer hens of the commercial hybrid Tetra SL had significantly higher egg weight and better internal egg quality (p<0.01) compared to hens of Banat Naked Neck and Svrljig hens, except for the colour of the yolk, which was more intense in the same feeding and breeding conditions and the age of laying hens, in eggs of native breeds (p<0.01). Native breeds in relation to the commercial hybrid had lighter shell colour (p<0.01). Deformation and egg shell thickness differed (p<0.01) between all three genotypes. The determined rank of layer hen genotypes for shell thickness was: Tetra SL, Banat Naked Neck, Svrljig hen. However, the breaking force was without statistically confirmed difference between hen genotypes.