Effects of dietary rubber seed oil on production performance, egg quality and yolk fatty acid composition of Hy-Line Brown layers

OBJECTIVE: This study aims to evaluate the effects of dietary supplement of rubber seed oil on production performance, egg quality, and yolk fatty acid composition in laying hens during a 16-week feeding trial period. METHODS: Forty-eight 25-week-old laying hens of Hy-Line Brown were randomly divided into three groups. Each group comprised four replicates and each replicate had four birds. Rubber seed oil was incorporated into a corn-soybean meal basal diet by 3.5% (group I), 4.5% (group II), or 0 (control group) and equivalent nutrition was supplied for the test groups and the control group. The performance related values were determined using standard or well established methods. RESULTS: No significant difference was found in the production performance, the egg quality, the composition of saturated fatty acids, and the content of cholesterol and monounsaturated fatty acids in the yolk within the three groups. Interestingly, both test groups achieved a significantly higher content of linoleic acid, α-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid and a significantly lower content of arachidonic acid (p<0.05) compared with the control group. With the increased level of dietary rubber seed oil, there was an increasing trend in the content of n-6 polyunsaturated fatty acids (PUFA), n-3 PUFA and total PUFA, but a declining trend in the n-6/n-3 ratio. CONCLUSION: These results demonstrate that the rubber seed oil supplemented diet effectively improved the total PUFA content in eggs without impairing the layers’ production performance and the egg quality.