Effect of laying hens genotype on production performance and chemical composition of organic eggs

Abstract

Organic egg production has experienced a large expansion over the past few decades. The main reason for this is the consumers aspiration to consume quality products with added value, which are produced with care for the welfare of laying hens. Different genotypes can be used for this type of production, from highly productive hybrids to purebred birds, well adapted to less intensive rearing conditions. For this reason, this paper aimed to examine the effect of genotype on the production performances of organic laying hens and the chemical composition of organic eggs. The tested genotypes were the Isa Brown hybrid and the New Hampshire breed (30 birds per group). Production parameters (egg production, feed consumption and feed conversion) were monitored weekly during the one-year production cycle. In the 56th week of age, 15 eggs were taken from each experimental group (a total of 30 eggs) to determine the basic chemical composition of the eggs (content of dry matter, ash, protein and lipids). The Isa Brown hybrid had a significantly higher egg production (p<0.05) compared to the New Hampshire breed (77.88% : 55.98%). New Hampshire layers consumed significantly more (p<0.05) feed (129.43 g) than Isa Brown hens (125.54 g), which contributed to the feed conversion to egg mass (kg feed/kg egg mass) being significantly better in hybrid layers (3.03 : 5.55; p<0.05). On the other hand, New Hampshire eggs had a higher content of dry matter (25.06% : 26.62%), ash (0.93% : 0.87%) and lipids (10.37% : 8.70%) compared to the Isa Brown (p<0.05). Only in the protein content there no significant differences between the tested genotypes (12.41% : 12.37%; p>0.05). From the above results, it can be concluded that the Isa Brown hybrid was superior in production results compared to the New Hampshire breed, while the eggs of the New Hampshire had better nutritional characteristics compared the eggs of the Isa Brown.