Unlocking the potential of zeaxanthin: A cost-effective carotenoid supplementation for enhanced growth, pigmentation, and health in Litopenaeus vannamei

Carotenoids are essential dietary components in aquaculture, widely used to enhance pigmentation, improve stress tolerance, and boost immune responses in aquatic animals. However, the high cost of traditional carotenoids, such as astaxanthin, has prompted research into alternative, cost-effective sources like zeaxanthin (Zea). This study aimed to evaluate the effects of varying dietary levels of Zea on the growth performance, antioxidant capacity, immune responses, pigmentation, and hypoxia tolerance of Litopenaeus vannamei over an eight-week feeding trial. A total of 600 shrimp were fed experimental diets containing incremental levels of Zea (0, 50, 100, 200, and 400 mg/kg). Growth performance metrics, proximate composition, enzymatic activities, carotenoid composition, and tolerance to hypoxia stress were analyzed.The results showed that dietary Zea supplementation significantly improved final body weight (FBW), survival rate, specific growth rate (SGR), and feed conversion ratio (FCR). Shrimp fed 200 mg/kg Zea exhibited the highest antioxidant enzyme activities, reduced malondialdehyde (MDA) levels, and enhanced immune enzyme activities (AKP, ACP, lysozyme). Furthermore, dietary Zea effectively increased tissue astaxanthin levels, improved pigmentation (a* and b* values), and enhanced tolerance to hypoxia stress (LT50). The study also highlighted that the effects plateaued beyond 200 mg/kg of dietary Zea inclusion, indicating tissue saturation.This research provides compelling evidence for the potential of Zea as a cost-effective alternative to traditional carotenoids in aquaculture. The findings contribute to optimizing shrimp feed formulations, improving sustainability, and reducing production costs while maintaining high product quality.