Haematological profile and growth performance of Clarias gariepinus fed diet fortified with cotton (Gossypium herbaceum) leaf extract

High reliance on synthetic antibiotics in fish production has contributed to concerns about antibiotic resistance, creating interest in natural feed additives. This study investigated the effect of cotton leaf extract (CLE) on the haematological profile and growth performance of Clarias gariepinus. A total of 270 fingerlings (0.82 ± 0.13 g) were randomly distributed into 18 rectangular tanks (15 fish per tank) in a completely randomized design comprising six treatments replicated three times. The treatments were a basal commercial diet without additive (0.0 g/kg), an Aquaceryl reference diet containing 0.15 g/kg Aquaceryl+, and diets supplemented with 0.1, 0.2, 0.3, and 0.4 g CLE/kg diet. Fish were fed twice daily to apparent satiation for 60 days. Fish growth variables and blood samples were collected from three fish per replicate at the end of the feeding trial and analysed using standard haematological procedures. Data were analysed using one-way analysis of variance (ANOVA) and Duncan’s multiple range test at P < 0.05. Dietary CLE significantly improved final weight, weight gain, and specific growth rate, with the strongest responses generally observed at 0.2 and 0.3 g CLE/kg diet. Fish fed 0.2–0.4 g CLE/kg diet had significantly higher lymphocyte counts (P < 0.05), whereas red blood cell counts did not differ significantly among treatments (P > 0.05). Haemoglobin concentration differed significantly among treatments, with the highest value recorded at 0.2 g CLE/kg diet. Cotton leaf extract at 0.2 g/kg diet is recommended based on the combined growth and haematological responses observed in this study.