Influence of rapeseed cake, linseed cake and hemp seed cake on laying intensity, egg composition and fatty acid composition of egg yolk in laying hens

Oil seed meals, solvent extracted, and oil seed expeller-cakes are important protein and energy sources in animal feeding. Plant oil supplements to laying hen diets are primarily used to satisfy the essential fatty acid requirement. The different shares of polyunsaturated fatty acids in the different lipid sources can be used to modify the fatty acid composition of egg yolk (Ohtake and Hoshino, 1967; Noble et al., 1990; Halle, 2000; Antruejo et al., 2011) which might have health benefits for the consumer. Rapeseed was grown on 1.46 million ha in Germany in 2010 contrasting with only 6.86 thousand ha linseed and 1.2 thousand ha hemp. Three million tons rape seed meal and 4.9 million tons other oil seed meals, mainly imported soya-bean meal, were used as protein feed (UFOP Bericht, 2010/2011; EFSA, 2011). Objectives of this study were to press the seeds from rape, linseed and hemp in the same screw press and to test the respective cakes in an experiment with laying hens. Besides the laying intensity and egg quality parameters, the fatty acid composition of egg yolk had to be investigated.