GROWTH AND ECONOMIC PERFORMANCE OF DEVELOPMENTAL STAGES OF THE AFRICAN CATFISH, Clarias gariepinus (BURCHELL 1822) FED WITH FARM-MADE FEEDS

Abstract

This study was carried out to evaluate the effect of farm-made aquafeeds using a combination of poultry feeds, bovine blood meal and oil seed meals on three developmental stages: fingerlings, juveniles and growers of Clarias gariepinus (Burchell 1822). For each developmental stage, three farm-made feeds were formulated and a commercial feed was used as the reference diet. For the fingerlings’ stage (Experiment I), the farm-made feeds were formulated at 45% crude protein (CP) and 8% lipid, designated as F1, F2 and F3 being toasted soybean meal, poultry feed and bovine blood meal blend, cracked-and-cooked soybean meal, poultry feed and bovine blood meal blend and autoclaved soybean meal, poultry feed and bovine blood meal blend respectively. Coppens® aquafeed of 2mm diameter grains’ size was used as fingerlings’ reference diet (FRD). For the juveniles’ stage (Experiment II), the farm-made feeds were formulated at 40% CP and 10% lipid, designated as J1, J2 and J3 which were the toasted soybean meal, poultry feed and bovine blood meal blend, cracked-and-cooked soybean meal, poultry feed and bovine blood meal blend and autoclaved soybean meal, poultry feed and bovine blood meal blend respectively. Coppens® aquafeed of 3mm diameter grains’ size was used as juveniles’ reference diet (JRD). The growers’ stage (Experiment III) was formulated at 38% CP and 12% lipid, and designated as G1, G2 and G3 which were the toasted soybean meal, poultry feed and bovine blood meal blend, cracked-and-cooked soybean meal, poultry feed and bovine blood meal blend and autoclaved soybean meal, poultry feed and bovine blood meal blend respectively. Coppens® aquafeed of 6mm diameter grains’ size was used as growers’ reference diet (GRD). These diets were used to feed the different developmental stages of Clarias gariepinus for a period of 70 days during which the growth response, nutrient utilization and economic performance were evaluated. The best values for growth and nutrient utilization parameters evaluated (final weight [FW], weight gain [WG], average daily weight gain [ADWG], specific growth rate [SGR], protein efficiency ratio [PER] and feed conversion ratio [FCR]) in each developmental stage were recorded in the fish fed the reference diets (FRD, JRD and GRD), with values as: FW: 150.97±6.25, WG: 109.60±6.97, ADWG: 1.57±0.097, SGR: 1.85±0.09, PER: 2.74±0.17 and FCR: 0.91±0.061 in Experiment I (FRD); FW: 767.23±10.79, WG: 410.53±11.90, ADWG: 5.86±0.06, SGR: 1.094±0.02, PER: 1.027±0.03 and FCR: 1.219±0.03 in Experiment II (JRD); FW: 2126.50±110.95, WG: 626.90±108.16, ADWG: 8.956±1.54, SGR: 0.498±0.08, PER: 2.299±0.57 and FCR: 1.358±0.25 in Experiment III (GRD). This was followed by that of the fish fed the toasted soybean blends (F1, J1 and G1), in all the developmental stages, that is, irrespective of the inclusion level of proteins and lipids as required and prepared for each developmental stage with values as: FW: 127.77±3.89, WG: 85.90±3.74, ADWG: 1.39±0.240, SGR: 1.59±0.06, PER: 2.15±0.09 and FCR: 1.17±0.055 in Experiment I (F1); FW: 624.40±8.36, WG: 266.50±8.76, ADWG: 3.81±0.12, SGR: 0.795±0.02, PER: 0.666±0.02 and FCR: 1.877±0.06 in Experiment II (J1); FW: 1890.10±27.14, WG: 359.23±38.47, ADWG: 5.132±0.55, SGR: 0.301±0.03, PER: 1.891±0.20 and FCR: 2.338±0.26 in Experiment III (G1). Next were the cracked and cooked blends (F2, J2 and G2), with values as: FW: 107.80±4.19, WG: 66.20±5.01, ADWG: 0.95±0.071, SGR: 1.36±0.08, PER: 1.66±0.12 and FCR: 1.51±0.123 for Experiment I (F2); FW: 573.87±25.32, WG: 215.87±25.93, ADWG: 3.08±0.37, SGR: 0.673±0.06, PER: 0.540±0.07 and FCR: 2.337±0.26 for Experiment II (J2); FW: 1840.40±41.73, WG: 299.73±50.70, ADWG: 4.282±0.73, SGR: 0.254±0.05, PER: 1.577±0.27 and FCR: 2.835±0.49 for Experiment III (G2). The least performance was recorded in the autoclaved soybean blends (F3, J3and G3) with values as: FW: 105.30±3.74g, WG: 63.97±4.14g, ADWG: 0.91±0.057g, SGR: 1.34±0.07, PER: 1.60±0.11 and FCR: 1.57±0.106 for Experiment I (F3); FW: 541.57±21.49g, WG: 183.43±20.84g, ADWG: 2.62±0.30g, SGR: 0.59±0.05, PER: 0.459±0.05 and FCR: 2.749±0.31 for Experiment II (J3); FW: 1826.37±22.74g, WG: 291.93±32.28g, ADWG: 4.170±0.46g, SGR: 0.249±0.03, PER: 1.537±0.17 and FCR: 2.879±0.32 for Experiment III (G3). Among the farm – made aquafeeds, best overall performance for the growth and nutrient utilization parameters evaluated (FW, WG, ADWG, SGR, PER and FCR) in each developmental stage were recorded in the toasted soybean meal blends (F1, J1 and G1). Although the reference diets (FRD, JRD and GRD) had the best growth and nutrient utilization, some of the indices examined were not significantly different (p>0.05) from that of the toasted soybean meal blends (F1, J1 and G1). In the economic evaluation for the fingerlings’ developmental stage, in terms of Profit Index (PI) and Incidence of Cost (IC), two of the farm-made aquafeeds (F1 [1.58, 0.51] and F2 [1.19, 0.67]) had better performance than FRD (1.10, 0.73), with F1 having the best overall performance. In the juveniles’ developmental stage, in terms of Profit Index (PI) and Incidence of Cost (IC), J1 (1.96, 0.41) had the best overall performance, followed by JRD (1.64, 0.49), next was J2 (1.55, 0.52) and lastly J3 (1.10, 0.73). In the growers’ developmental stage, in terms of Profit Index (PI) and Incidence of Cost (IC), the best overall performance was recorded in G1 (1.58, 0.51), followed by GRD (1.50, 0.53), then G2 (1.29, 0.62) and lastly G3 (1.04, 0.77). Among the developmental stages, the juveniles were also found to have recorded the best performance in terms of the highest PI (1.64, 1.96, 1.55, 1.10), lowest IC (0.49, 0.41, 0.52, 0.73) and 100% survival rate during the experimental period. This study therefore recommends that the toasted soybean meal blend, which has the best economic performance overall in all the developmental stages, with growth and nutrient utilization indices next to the reference diets, should be considered in feeding the different developmental stages of C.gariepinus.and the juveniles’ developmental stage should be used for stocking in order to get the best result.