Effect of goat weed leaf meal (Ageratum conyzoides) as a partial dietary replacement for maize in the diet of African catfish (Clarias gariepinus)

Abstract

It is crucial to find ways to employ less expensive conventional materials in fish farming to lower production costs without adversely affecting the general performance of the fish. Consequently, certain neglected plants, such as goat weed leaves that have been reported to have the potential to serve as a partial substitute for maize (energy source) must be considered. Therefore, this research evaluated the effects of partially replacing maize with goat weed leaf meal (Ageratum conyzoides) (GWLM) on the growth, haematology, and serum enzyme indices of Clarias gariepinus. A 56-day feeding trial was conducted with a total of 500 juveniles with an average weight of 13.7 g. After sterilizing the fish in a mixture of potassium permanganate and water to reduce stress, a one-week acclimatisation period was ensured using commercial feed (2 mm). Subsequently, the juveniles were randomly stocked in quadruplets of 25 fish per culture tank measuring 1.2 m x 1.2 m x 0.9 m each (labelled Ai-iv, Bi-iv, Ci-iv, Di-iv, and Ei-iv) based on the number of repetition and the diet to be fed. A total of five (5) different diets with varying levels of dietary inclusion (A: 0%, B: 2%, C: 4%, D: 6%, and E: 8%) of goat weed leaf meal (GWLM) as a partial replacement for maize were formulated to contain a minimum crude protein level of 40%. The test diets were administered twice daily (7:00 hrs. and 18:00 hrs.) and the sampled fish were adequately fed (5% body weight) with proper follow-up to monitor feeding behaviour. The data collected from the research were subjected to a one-way analysis of variance (ANOVA) using the SPSS version 23 analysis package. Furthermore, a Duncan multiple-range test was employed to separate the means. There were notable (p < 0.05) variations in various parameters (proximate composition, digestibility of nutrients, growth performance, haematological and serological profiles, and water quality) observed in all treatments as the inclusion of the test ingredient in the diet increased. However, as the inclusion levels of the test ingredient increased above 4%, a steady decline was observed between treatments. At a 4% dietary inclusion level, the best performance indices (weight gained (36.52g), feed conversion ratio (2.15), specific growth rate (2.31) and survival rate (95%)), and blood profile (haematology and serum enzyme indices) were observed. Therefore, a 4% replacement of maize using goat weed leaf meal (GWLM) in the diet is suitable for an optimum performance of African catfish.