Dietary Methanolic Extracts of Justicia carnea and Ocimum gratissmium on Growth Response, Haematological Indices and Serum Biochemical Profiles of Female African Catfish (Clarias gariepinus)

A total of 300 juvenile female African catfish sourced from Tolu’s Farms, Enugu State, were used in this study. Upon arrival, the fish were acclimatized for one week and then randomly allocated to four treatment groups following a 2x2 factorial arrangement in completely randomized design (CRD), with each treatment replicated four times. The fish were fed diets containing varying levels of Justicia carnea and Ocimum gratissimum leaf extracts. Fresh leaves of Justicia carnea (JC) and Ocimum gratissimum (OG) were harvested from a greenhouse farm, thoroughly cleaned, air-dried, and milled into powder. The powdered samples were subjected to methanolic extraction at the Biochemistry Laboratory of the Department of Animal Science. Twenty-five grams (25 g) of each extract were diluted in 50 cl of water. Subsequently, 1 kg of fish feed was separately and uniformly mixed with 50 ml of JC extract and 25 ml of OG extract. Data obtained were analyzed statistically using IBM SPSS statistics version 23. The results obtained showed that the inclusion of the plant extracts significantly enhanced the growth performance of the fish. Hematological parameters indicated that treatments T3 and T₄ recorded the highest packed cell volume (PCV), red blood cell (RBC) counts, and hemoglobin (Hb) concentrations, which were significantly higher (p < 0.05) than those of the control group (T₁). Similarly, serum biochemical analysis revealed significantly lower (p < 0.05) low-density lipoprotein (LDL) levels in T₃ and T₄ compared with T₁. In contrast, the control group (T₁) exhibited higher levels of aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) relative to the treatment groups. Furthermore, total cholesterol and creatinine levels were significantly reduced in fish from T₃ and T₄ compared with the control. These findings indicate that dietary supplementation with Justicia carnea and Ocimum gratissimum leaf extracts enhances growth performance and improves hematological and serum biochemical indices, thereby promoting the safety and quality of fish meat. In conclusion, these plant extracts showed considerable potential as natural dietary supplements for use in aquaculture.