Dietary DL-alpha-tocopheryl acetate enhances growth, survival, and resistance against an abrupt shift to higher salinity of the Asian catfish (Clarias macrocephalus) fry

The effect of dietary supplementation of DL-alpha-tocopheryl acetate (a-TA) on growth performance, feed efficiency, survival, and salinity resistance of Asian catfish (Clarias macrocephalus) fry was evaluated. A total of 750 catfish fry were divided into five treatments with three replicates and fed experimental diets containing varying levels of alpha-TA: 0, 100, 200, 300, and 400 mg·kg-1 diet for 45 days. Results show that catfish fry-fed diets supplemented with alpha-TA exhibited significantly higher weight gain (WG) and final average body weight (FABW), better specific growth rates (SGR) and feed conversion ratio (FCR), and significantly higher survival rates compared to those of the control group fed the basal diet (P < 0.05). Better salinity resistance was observed in the Asian catfish fed the alpha-TA-supplemented diets when abruptly exposed to higher salinity (10 ppt) for up to 48 h. In addition, the diet attractability test revealed that alpha-TA-supplemented diets attracted significantly more catfish fry than the basal diet lacking vitamin E (P < 0.05). In conclusion, the results demonstrated that dietary supplementation of alpha-TA (vitamin E) improved growth, feed efficiency, feed attractability, survival, and resistance to abrupt higher salinity exposure of Clarias macrocephalus fry.