The effect of ellagic acid on performance, digestibility, cecal bacterial flora, antioxidant activity and some blood parameters in laying quails reared under different temperatures

In this study, the effects of ellagic acid in quails which fed under normal conditions and high ambient temperatures on the performance, egg quality, digestibility of crude nutrients, total coliform and total lactic acid bacteria in the intestine, serum MDA level and some blood parameters (glucose, total protein, cholesterol, AST, ALT, calcium, phosphorus, magnesium, sodium) were investigated. The birds (n=240; 5-weeks old) reared under two environmental temperature [Thermoneutral (TN) and Heat stress (HS)] and four diet groups containing four different ellagic acid doses (0, 100, 200 ve 400 mg/kg) were assigned randomly to 8 groups according to the 2 x 4 factorials trial arrangement. Feed consumption, egg weight and egg production were higher (P <0.001) and feed conversion ratio (FCR) (P <0.01) were better in TN groups than HS groups. Egg (P<0.01) and shell weights (P<0.001) were found higher in TN groups when compared to HS groups while there was no statistically significant difference between the groups in terms of shell thickness, yolk index, albumen index and haugh unit (P<0.05). The effect of ellagic acid addition on egg and shell weight was statistically significant (P<0.05). The effects of ambient temperature and the addition of ellagic acid on digestibilities of dry matter (P<0.05), ether extract (P<0.01) and crude protein (P<0.01) were statistically significant. The effect of ellagic acid on digestibilities of dry matter (P<0.05), crude fat (P<0.01) and crude protein (P<0.01) were statistically significant. Ellagic acid supplementation had reduced the total number of coliform bacteria in the intestine (P<0.01) and increased the total number of secum lactic acid bacteria (P<0.001). Serum MDA levels increased with the heat stress (P<0.001) and decreased with the addition of ellagic acid (P<0.001). While the effect of ambient temperature on serum glucose (P<0.001), cholesterol (P<0.05), total protein (P<0.05), ALT (P<0.001), sodium (P<0.05) and magnesium was significant, its effect on serum AST, calcium and phosphorus levels was not significant (P>0.05). In conclusions, in this study, the addition of ellagic acid in quails under heat stress decreased the oxidative stress, serum cholesterol, AST-ALT levels and number of total coliform bacteria and improved the feed conversion ratio and egg quality. Moreover, ellagic acid increased the digestibility of nutrients and, it had a positive effect on the lactic acid bacteria that are beneficial bacterium in the secum. It has been observed that these beneficial effects of ellagic acid increases with the increasing dose, and 400 mg/kg was the most effective dose in this study.