The dietary effect of adding sodium propionate on some growth indices, survival rate, and some immune responses of gold fish (Carassius auratus)

In the present study, the effects of dietary sodium propionate as an acidifier additive on some indices of growth, survival rate, and serum immunity of goldfish were investigated. In this study, 240 fish with an average initial weight of 7.2±0.75 g were randomly distributed in 12 aquariums. The fish were fed with the levels of 0 (control), 1.5% and 2.5% sodium propionate in the feed for 60 days. The results showed that weight gain, weight gain percentage, specific growth rate, condition coefficient, and survival rate in the treated fish were significantly higher than the control group (P<0.05). However, the highest feed conversion ratio was observed in the control group (P<0.05). Also, the highest levels of serum immunoglobulin M (9.64±0.11 mg/l) and lysozyme (15.61±1.03 μg/ml/min) were observed in 2.5% sodium propionate treatment compared to others (P<0.05). According to the results of this study, the use of 2.5% sodium propionate in goldfish diet acts as a growth stimulator and can enhance the growth performance along with the immune system.