Aquaculture is a growing agribusiness, and large-scale microbial infection frequently leads to considerable economic losses, as there are very few approved drugs available to counteract such a problem. Aloe vera is a natural therapeutic plant with biological activities, for example, antimicrobial, anticancer, mitigating, and immunomodulatory properties. Thus, an experiment was conducted to understand the effects of dietary Aloe vera on survival, growth performance, protein utilization, gastrosomatic index, and gut histomorphological studies in common carp in laboratory conditions. Aloe vera leaves were collected, washed, shade-dried, and homogenized to get a filtrate, which was extracted in ethanol (70%) using the Soxhlet apparatus. The carp with an average weight of 1.73 ± 0.14 g was divided randomly into 5 treatments (control and other 4 treated groups) with the extract of 0.0%, 0.2%, 0.4%, 0.8%, and 1.6% in the diet with 3 replicates and the stocking density was 25 fish per each replicate. Sampling was done on the 30th, 60th, and 90th days, and the results show that percent weight gain, specific growth rate, protein efficiency ratio, and feed conversion efficiency were significantly high in the treated diet compared to the control (0.0%). Gastrosomatic index, condition factors, and gut histology found better performance in common carp group fed 0.4% and 0.8% of Aloe vera after 90 days. In conclusion, it was found that Aloe vera extract between the amount of 0.4% and 0.8% is better for fish growth for common carp.
