Effects of dietary leaf ethanolic extract of Apium graveolens L. on growth performance, serum biochemical indices, bacterial resistance and lysozyme activity in Labeo chrysophekadion (Bleeker, 1849)

This research was conducted to evaluate the effects of Apium graveolens leaf extract on Labeo chrysophekadion. The fish were fed 0, 0.25, 0.50 and 0.75 g kg−1 leaf extract to supplement their diets for 150 days. The results revealed that the highest weigh gain and average daily gain being observed in fish that were fed 0.75 g kg−1. Furthermore, a lower feed conversion rate was observed in fish fed 0.50 and 0.75 g kg−1. Biochemical indices, the highest cholesterol level was found in a group fed 0.75 g kg−1, while glucose was found to be significantly higher in groups fed 0.25 and 0.50 g kg−1. Total protein, albumin and globulin levels were shown to have significantly (p < 0.05) increased alongside an increase in the concentration of the extract and higher levels were found in groups fed 0.50 and 0.75 g kg−1. After pathogenic challenge test, the highest level of lysozyme activity was observed in a group fed 0.25 g kg−1. The lowest cumulative mortality was observed in a group fed 0.75 g kg−1 when compared with other groups. These results suggest that 0.75 g kg−1 of A. graveolens this can promote growth performance, enhance some biochemical indices, disease resistance and non-specific immune response.