Effects of different levels of dietary butyric acid on some growth performance, immunity and digestive enzymes activity of yellowfin seabream (Acanthopagrus latus Houttuyn, 1782)

This study was conducted to evaluate the effects of different dietary levels of butyric acid on growth performance, immunity and digestive enzyme activities in yellowfin seabream (Acanthopagrus latus) (8.59 ± 0.33 g) at the period of 60 days. After 2-week adaptation, 120 fish with a density of 10 fish/tank in a completely randomized design were distributed to 12 tanks. Fish were fed with 4 levels of butyric acid including zero (control), 2.5 (T1), 5 (T2) and 10 g/kg (T3) of diet 2 times per day. The results showed that different levels of butyric acid in diet had significant effects on growth performance and nutritional indices compared to the control (p<0.05). However, protein productive value of T1 and control exhibited no significant difference (p>0.05). The food conversion ratio in control group was significantly higher than in the other treatments (p<0.05). Nonspecific immune responses, lysozyme activity and ACH50 in T3 were also significantly higher than in the other treatments (p<0.05). Protease activity in T3 and also amylase in T2 and T3 were significantly increased compared to the control (p<0.05), whereas lipase activity did not exhibit any significant difference (p>0.05). In conclusion, butyric acid, especially at the level of 10 g/kg of diet, displayed positive effects on the growth, immune indices and enzyme activities in yellowfin seabream.