Phytochemical composition of Syzygium aromaticum and its effects on growth performance and feed efficiency of Clarias gariepinus

Abstract

Nutraceuticals are natural substances that are food or part of food to provide medicinal and health benefits, and also have the potency to prevent and treat diseases. The present study evaluated phytochemical compositions of clove (Syzygium aromaticum) flower bud extract with a view to evaluating its potential as a natural dietary additive in Clarias gariepinus diet. Clove powder was incorporated at four levels (0, 5, 10 and 15%) of the experimental diets and fed to the fish in triplicate for 84 days. All analytical protocols followed standard procedure. Phytochemical screening of clove revealed the presence of primary metabolites: carbohydrates, proteins, and lipids (in trace to moderate amounts), as well as secondary metabolites: alkaloids, flavonoids, tannins, sterols, saponin, cardiac glycosides, and phenolic compounds. Proximate analysis of clove extract showed high levels of carbohydrates (46.65±0.006%) and lipids (21.67±0.003%), with a caloric value of 413.83 kcal/100g, while protein content was relatively low (8.05±0.006%). Mineral analysis revealed potassium (10.10±1.03 mg/100g) as the most abundant element, followed by calcium, phosphorus, iron, magnesium, and zinc. Nutrient analysis showed appreciable amounts of vitamins A, B1, B2, and C., while anti-nutritional factors such as oxalate and phytate were present in low concentrations. The catfish treated with 15% clove extract in diets had the best specific growth rate (0.46±0.67%/day), average daily growth (1.56±0.01g/day), food conversion ratio (0.131±0.00) and protein efficiency ratio (37.6±3.40). Fish condition factor and survival rates followed similar trend. The results suggested that S. aromaticum extract contained beneficial phytochemicals and essential nutrients which may be suitable for use as a natural feed supplement. These bioactive compounds enhanced fish growth and feed utilization which increased with inclusion levels in diets. Thus, the use of clove bud extract in catfish feed in hereby encouraged.