RAPESEED CAKE, GLYCERIN AND DISTILLERS DRIED GRAINS WITH SOLUBLES USED SIMULTANEOUSLY AS A SOURCE OF NUTRIENTS FOR HENS IN THEIR SECOND LAYING SEASON

Bovans Brown laying hens in their second season of lay (front 81 to 100 weeks of age) were allocated to 8 groups with 18 replicates, liens were kept in individual cages, at 14L:10D and fed ad libitum. All diets were isocaloric and isonitrogenous and contained 4% of rapeseed glycerin (RG), from 2% to 6% of rapeseed expeller cake (REC), and front 5% to 15% of distillers dried grains with solubles (DDGS). Control diet contained no biofuel co-products. The dietary crude fibre content increased front 3.5% in control group to 4.6% in experimental groups. The number and weight of eggs were registered daily, feed consumption was recorded monthly, and laying rate, daily egg mass, daily feed intake and feed conversion ratio per kg of eggs and per egg were calculated. One egg from each hen was collected to determine egg quality indices, and a further 8 eggs from each treatment were collected for sensory evaluation. The dietary levels of REC, RG and DDGS did not affect the laying rate, weight of laid eggs, feed intake, feed conversion ratio and egg quality indices (P>0.05). The flavour of boiled eggs from the control group was significantly better (P<0.05) than from the experimental groups with 10% DDGS and 4-6% REC. The taste of control eggs was significantly (P<0.05) better than that of eggs front the experimental groups. The results of this study indicate that performance of older layers does not deteriorate as a result of adding 4% RG, 2-6% REC and 5-10% DDGS to the diets. Sensory characteristics of boiled eggs from experimental groups were poorer than in control but nevertheless all eggs were suitable for consumption.