The addition of green propolis to laying hens had positive effects on egg quality: lower bacteria counts in the shell and lipid peroxidation in the yolk.

This study aimed to determine whether the addition of green propolis extract to the diet of laying hens would improve egg quality and bird performance and decrease bacterial contamination of eggs. Forty-five brown Hy-line laying hens were used, divided into five groups with three replicates each and three animals per cage: T0 - diet without propolis; T5 - 5 grams of propolis per kg of feed; T10 - 10 grams of propolis per kg of feed; T20 - 20 grams of propolis per kg of feed and T30 - 30 grams of propolis per kg of feed. The quality of fresh eggs was made on day 21 of the experiment, and eggs were stored for 21 days.