Chasteberry, Vitex agnus-castus, extract as a natural enhancer for growth, chemical composition and hematological parameters in Nile tilapia (Oreochromis niloticus)

Abstract

Integrating natural plant-based additives into aquafeeds has gained growing interest as a sustainable strategy to to improve growth and health in aquaculture. Vitex agnus-castus, commonly known as chasteberry, is recognized for its bioactive compounds with antioxidant, anti-inflammatory, and endocrine-modulating properties. This study aimed to evaluate the effects of dietary supplementation with chasteberry tree extract (CTE) on growth performance, muscle chemical composition, and hematological parameters in Nile tilapia. A total of 72 pre-market-sized tilapia (average weight 139.6±0.46 g) were randomly distributed into 12 net cages (1 m3). Four experimental groups were designed to supplement the basal diet with 0, 0.25, 0.5, and 1.0 g CTE per 100 g diet in triplicate. Fish were fed 3% of body weight, twice a day, six days a week, for 45 days. Results revealed that fish fed diets supplemented with 0.5% CTE exhibited significantly higher final body weight, weight gain, specific growth rate and improved feed conversion ratio compared to other groups (P<0.05), with no significant difference in survival rate. Chemical analysis of muscle tissue showed that 0.25% and 0.5% CTE groups had significantly increased moisture and ether extract content (P<0.05), while crude protein, ash and gross energy showed no significance. Hematological analyses showed that the 0.5% CTE group had significantly elevated white blood cells, hemoglobin, hematocrit, glucose, and total protein levels, indicating an enhanced immune and metabolic response. These findings clearly recommend the use of 0.5% CTE as a promising natural feed additive to enhance tilapia growth and physiological status, contributing to more sustainable aquaculture systems.