Nutritional effects of additives containing organic acids, cinnamaldehyde and permeabilizer on some growth indices and intestinal structure of whiteleg shrimp, Litopenaeus vannamei

This study investigated the effects of feed additive containing organic acids, cinnamaldehyde and permeabilizers on growth rate and intestine structure of whiteleg shrimp (Litopenaeus vannamei). So, five isoproteic (∼38%) diets containing different levels of 3, 6, 9 and 12 g/kg (T3, T6, T9 and T12, respectively) commercial additive Biotronic Top 3 were formulated and a diet without this additive were considered as a control. Shrimps (2.7 g in average weight) were randomly placed in fifteen 300-liter fiberglass tanks containing sea water (20 shrimps in each tank) and each experimental treatment was in triplicate. Shrimps were fed at the rate of 7% of their body weight three times a day. At the end of the experiment, the average final weight in shrimps fed with diets containing additives was significantly higher than the control group (p<0.05). The highest average final weight was observed in T3. However, the addition of higher levels of this additive did not show any significant effect on the final weight of shrimps (p>0.05). The food conversion ratio in the treatments fed with additives, (except for T9) was significantly lower than the control group (p<0.05). Examining the shrimp intestine showed that using this additive elevated the height of the intestinal villi. In general, according to the findings of this study, dietary supplementation of Biotronic Top 3 at 3 g/kg can enhance the growth rate and intestine histology of whiteleg shrimp.