Authors : O.A. Oyelese
Abstract: This study intends to promote the rearing (production) and marketing of the African giant snail (Archatina marginata) especially for the production of processed snail meal to supplement the conventional fish meal in the diets of Clarias gariepinus as used in this study. The visceral mass (entire flesh) of about 150 pieces of snail (Archatina marginata) were washed with alum and water. They were cut into pieces and dried in an oven at a temperature range of 60-70°C in an oven for about 72 h. The dried snail meat was used in compounding 6 isonitrogenous diets each with Crude Protein (C.P) of 38.25%; labeled 0% (no snail meal) (Control) 20, 40, 60, 80 and 100% snail meal diets (i.e. Treatments 1, 2, 3, 4, 5 and 6). The processed snail meal (with C.P 55.16%) was gradually being supplemented with fishmeal (C.P 65.00%) in each of the diets. The diets were fed to 90 juvenile Clarias gariepinus of average weight range from 4.35-4.63 g randomly distributed in 6 plastic bowl (15 fish per bowl). The fish were fed this 6 diets twice daily (10.00 a.m. and 5.00 p.m.) for an experimental period of 12 weeks (84 days). Proximate analysis of the feed, initial and final proximate composition of the experimental fish were also determined. Fish were weighed weekly and feed fed daily were recorded to determine growth and nutrient utilization pattern of the experimental fish. The best grow out of fish and best nutrient utilization pattern was recorded in Diet 4 (60% snail meal inclusion) with the highest Mean Weight Gain (MWG) (7.33 g), Specific Growth Rate (SGR) (1.154), Protein Efficiency Ratio (PER) (0.620) and Gross Efficiency of Food Conversion (GEFC) (0.240) but with the least Food Conversion Ratio (FCR) (0.34). The second best diet is Diet 3 (40% snail meal inclusion). While the poorest diet (Diet 6) (100% snail meal inclusion) recorded the lowest Mean Weight Gain (MWG) (2.22 g), SGR (0.500), PER (0.250), GEFC (0.017) and highest FCR of 0.84. This implies snail mean is best when used in supplementation with conventional fishmeal at a ratio of 60% snail meal to 40% fish meal. The present cost of production of 1kg of processed snail meal is put at N250.00 kg 1 compared to N300.00 kg 1 of fishmeal (i.e., just with a profit margin of 16.67%) could still further be reduced by promoting the active rearing and marketing of the African Giant snail (Archatina marginata) especially for fishmeal production, snail meat protein supply to the populace coupled with its medicinal value and liming properties of the snail shell in improving the quality of acidic (fish pond) soils.
O.A. Oyelese , 2007. Utilization of Processed Snail Meal and Supplementation with Conventional Fishmeal in the Diet of Clarias gariepinus . Journal of Fisheries International, 2: 140-146.