Part 4 was a study on the stability of formulated carotenoid diets. All diets are split into two smaller groups which one contains antioxidant and another is without antioxidant at 250 mg/kg. Firstly, all diets were evaluated in total carotenoid (TC) loss during feed processing. In this study found that carotenoid content in all diets remained quite stable, without significant loss during feed processing. The TC loss in the diets starts from after being feed processed which are through from the pellet cooker and passed to die surface, and after dryer process, heat processes cause considerable loss of carotenoids. As a result, should be added 10 percents of TC from the needed amount to natural carotenoids or natural raw materials to achieve the target level TC. Nevertheless, pelleting process of the diets (with a pelleting machine: soft type pellet without steam) didn’t affect carotenoid content of the diets.