Growth performance, nutrient utilization and haematological indices of hybrid catfish fingerlings fed varying inclusion levels of toasted sword beans (Canavalia gladiata) seed meal in concrete tanks

Abstract

A feeding trial was conducted to evaluate the growth performance, nutrient utilization and haematological indices of hybrid catfish fingerlings fed varying inclusion levels of toasted sword beans (Canavalia gladiata) seed meal (TSBM) in concrete tanks. Five 40% isonitrogenous and 10% isolipid diets were formulated with five different inclusion levels of TSBM (D1-0%, D2-10%, D3-20%, D4-30% and D5-40%). 20 fishes were stocked into each of 15 net hapas (0.5m × 0.5m × 1m) suspended in outdoor concrete tanks of 40m3 total volume and the fishes were fed at 5% body weight daily for 10 weeks. At the end of the feeding trial fish fed D4 had the highest growth performance in term of final body weight (FWG), percentage weight gain (WG), specific growth rate (SGR) while fish fed D5 had the lowest significant value. The nutrient utilization in term of feed intake (FI), feed efficiency (FE), protein efficiency ratio (PER) and protein retention (PR) of the fish fed experimental diets also follow the same pattern as the growth performance. Whole-body proximate composition of fish fed all diets showed that inclusion of TSBM influenced moisture and lipid contents. The final haematological indices in contrast to the initial showed a range of elevated values in all the parameters measured PCV, WBC, RBC, Lymphocytes, Hb, MCHC, MCH, and MCV. It can be concluded that toasted sword beans (Canavalia gladiata) seed meal can be included in the diet of hybrid catfish (hetero-clarias) fingerlings up to 30% without any adverse effect on the growth and nutrient utilization.