Effect of dietary fatty acid saturation on egg production at end-of-lay
This study was conducted to investigate the effects of dietary fatty acid saturation on production performances of laying hens at end-of-lay. Five isoenergetic (12.6 MJ AME/kg DM) and isonitrogenous (170 g CP/kg DM) diets were formulated using different lipid sources at a constant 30 g/kg inclusion level. The control diet was formulated using a blend (50 : 50) of linseed- and fish oil, while the other treatments consist of pure fish oil (polyunsaturated n-3), sunflower oil (polyunsaturated n-6), high oleic acid (HO) sunflower oil (monounsaturated n-9) and tallow (SFA). Two hundred, individually caged Hy-Line Silver-Brown laying hens (20 weeks of age) were randomly allocated to the five dietary treatments (n = 40 replicates/treatment) and received the experimental diets for 54 weeks from 20 to 74 weeks of age. During weeks 58, 62, 66, 70 and 74 of age (end-of-lay period), all eggs produced were recorded and individually weighed while feed intake, as well as body weights of birds, were determined. Data for the respective collection weeks were pooled to calculate and statistical analyse production parameter means for the end-of-lay period. Average daily feed intake of birds in the polyunsaturated n-3 treatment (97.5 g/b/d) were the lowest while that of the polyunsaturated n-6 treatment (102.4 g/b/d) the highest. Furthermore, despite the significant effect of fatty acid saturation on feed intake, it had no effect on hen-day egg production, egg weight, egg output, feed efficiency or body weight of hens during end-of-lay. Since results of the current study fail to indicate a clear trend regarding dietary fatty acid saturation on feed intake of birds, it could be concluded that the long term exposure to a range of fatty acid saturation levels, has no negative effect on hen performance.
Keywords: Eicosapentoenoic-, docosahexaenoic-, α-linolenic-, linoleic acid