Growth performance of Clarias gariepinus (Burchell, 1822) fed with varying substitution levels of fish meal with cattle hoof meal

Abstract

Fifteen weeks (105 days) feeding trial was conducted to determine growth response and economic benefit of replacing fishmeal with cattle hoof meal (CHM) in the diets of African catfish (Clarias gariepinus) juveniles. Five isonitrogenous diets containing 42% crude protein were formulated in which CHM replaced fishmeal at 0%, 25%, 50%, 75% and 100% (coded as D2, D3, D4, D5 and D6 respectively). A commercial feed (D1) was used as reference diet. Two hapa partitioned into six treatments of three replicates each embedded in a concrete pond of 5m by 3m by 2m was used for the experiment. The fish were fed at 3% body weight three times daily between the hour of 6.00 am and 7.00am, 2.00 pm and 3.00pm, and 10.00 pm and 11.00 pm. The feeding ration was adjusted every three weeks after weighing. The mean of the monitored physico chemical parameters of the water in the experimental tank were pH (7.12), temperature (28.25oC), oxygen (5.77mg/l), ammonia (0.04mg/l), nitrite (0.04mg/l), nitrate (0.03mg/l) and bicarbonate (5.45mg/l). The proximate composition of cattle hoofs meal were 33.75% moisture content, 66% dry matter, 58.06% crude protein, 2.75% crude fibre, 3.25% crude lipid, 0.91% ash content and 1.78% Nitrogen free extract. Feeding trials indicated that all fish consumed the experimental diets actively. Fish fed with the commercial feed had the highest mean weight gain (204g), followed by those fed with the experimental diet with 25% of CHM (D3) (181g). The fish fed with the control diet with no cattle hoofs meal (D2) had lower mean weight gain compared to the fish fed with 25% CHM. The fish fed with 50% CHM, 75% CHM and 100% CHM exhibited a decreasing weight gain (148.60g, 143.73g and 129.00g respectively) as the substitution level of the CHM meal increased. The fish fed with 25% cattle hoof meal (D3) had the best growth performance and feed utilization proficiency (specific growth rate 2.58, relative growth rate 1403, protein efficiency ratio 1.67 and feed conversion ratio 1.47) among the fish fed the formulated diets (D2, D3, D4, D5 and D6). There was no significant difference (p˃0.05) in the survival value of fish fed with all the experimental diets. The fish fed with D3 had the best net profit (₦46.53) followed by D6 (₦45.63), D1 (₦42.54), D5 (₦41.61), D4 (₦31.49) and D2 (₦20.59) in decreasing order. This study revealed that CHM can replace fishmeal at a lower cost and efficient diets for Clarias gariepinus. The best result was produced at the substitution level of 25% inclusion of CHM. It is recommended that CHM be included in the feed of Clarias gariepinus at 25% for optimum growth performance and reduced cost of production.