Effect of different levels of grape pomace on egg production performance and egg internal quality during different keeping times and temperatures

An experiment was conducted to evaluate effects of different levels of grape pomace in diets of laying hens on egg production performance and egg internal quality traits during different times and temperatures. One hundred and sixty Leghorn laying hens in post-molting phase were assigned to four treatments with five replications and eight birds each based on completely randomized design. The birds fed experimental diets containing zero, 1.5, 3 and 4.5% of grape pomace for eight weeks. Egg samples from treatment 4 were selected and stored in different temperatures (4 and 27° C) and duration times (1 day, 1 week and 1 month after production) at the end of experiment, then their internal quality traits were evaluated. Results showed that with the use of 4.5% grape pomace, the egg production rate, egg weight, egg mass and feed conversion ratio of birds were not affected, but feed intake decreased (P