The effect of fresh leaf Ocimum gratissimum and dried buds Eugenia caryophyllata extracts on the tissues bacteriological changes of Clarias gariepinus juveniles

Abstract

The use of antibiotics has lead to antibiotic resistance and residual effects among others in fish tissue thus necessitate the advocate for alternative natural plants for antimicrobial activities in aquaculture. Effect of fresh leaf Ocimum gratissimum and dried buds Eugenia caryophyllata extracts on the tissues bacteriological changes of Clarias gariepinus juveniles were examined by dietary intake in 2016. Seven experimental diets: control (0.0%), OG1 (0.5%), OG2 (1.0%), OG3 (1.5%), EC4 (0.5%), EC5 (1.0%) and EC6 (1.5%) were formulated to 40% crude protein and fed to fish in triplicates. Fish (10.57±0.46g) were fed twice at 3% body weight for 84 days. Water and fish tissues were examined for total viable control (TVC) and total entearobactericea (TEB). The data were analysed using descriptive and ANOVA. The results revealed that fish fed control diet had higher TVC and TEB than other diet (p<0.05). The TVC and TEB also varies greatly among the organs with skin taken the lead, followed by the gill (p<0.05). It is therefore suggested that extracts of leaf Ocimum gratissimum and dried buds Eugenia caryophyllata in the diet of C. gariepinus significantly reduced TVC and TEB to acceptable values making it a promising immunostimulants candidate to promote organic aquaculture.

Keywords: Antimicrobial, aquaculture, Eugenia caryophyllata, extracts, Ocimum gratissimum