Effects of Dietary Supplementation of Essential Oils and Vitamin E on Performance, Egg Quality and Escherichia Coli Count in Excreta

This experiment was conducted to investigate the effects of dietary essential oil combination (sage, thyme, and mentha extracts) (EOC) and vitamin E (Vit E) supplementation on laying hens’ performance, egg quality, yolk Thiobarbituric Acid Reactive Substance (TBARS) values and Escherichia coli (E. coli)and Coli form bacterium counts in excreta. One-hundred and twenty Lohmann white layers (36 weeks of age) were randomly allocated to five treatment groups, each having six replicate cages as subgroups comprising of four hens. Experimental groups were fed the basal diet (control group), basal diet plus 150 ppm of EOC (EOC-1), 300 ppm of EOC (EOC-2), 150 ppm Vitamin E (Vit E-1),or300 ppm Vitamin E (Vit E-2).The performance parameters, except for egg production and feed consumption, were not affected by the essential oil combination and Vit E supplementation. Feeding 300 ppm EOC caused significant reduction in egg production as compared to other groups(P< 0.01). Dietary groups consumed less feed than the control group (P< 0.01). According to the control group, supplemental EOC and Vit E increased shell stiffness (kg/cm2) and shell weight (P< 0.01) but did not affect other egg quality parameters. The essential oil combination and Vit E supplementation reduced the values of TBARS in eggs refrigerated at 40C on days 0, 21, and 42 (P< 0.01). However, there was no effect on the content of E. coli and Coli form bacterium in excreta (P> 0.05). It may be concluded that Vit E can easily be replaced by essential oil combination at the level of 150 ppm for inhabitation of lipid oxidation, without having an adverse effect on performance of laying hens and quality of eggs.