Response of growing snails (Archachatina marginata) to diets containing quality protein maize
The study was designed to determine the effects of inclusion of quality protein maize (QPM) as substitute for normal maize in the diet of growing snails on feed intake, weight gain and feed efficiency, shell growth, and carcass composition. A total of one hundred and twenty growing snails of relatively the same size were randomly allotted to 3 dietary treatments and each treatment was replicated 4 times with 10 snails per replicate. The experimental design was completely randomized design. Three diets were formulated to contain 3 different types of maize in equal proportion. Diet 1 (T1) which contained the normal maize (TZBP), Diet 2 (T2) contained QPM (ART/98/SW5/OB) while Diet 3 (T1) contained QPM (ART/98/SW6/OB). There was significant difference (P<0.05) in the mean feed intake of snails fed the experimental diets. The lowest feed intake of 1192.33g was recorded in the treatment containing normal maize (T1) compared to 1241.40g and 1246.72g recorded in the treatments containing QP1 (T2) and QP2 (T3). The highest weight gain of 303.34g was recorded in T3 which was relatively similar to T2 while the lowest weight gain of 258.08g was recorded in T1 (P<0.05) containing normal maize. The feed efficiency was better in the diet that contained high quality protein maize (P<0.05), the feed conversion ratio of 4.62 was recorded in snails fed normal maize while 4.10 and 4.11 was recorded in diet 2 and diet 3 containing quality protein maize. The results of the carcass evaluation revealed that the dressing percentage of the snails was significantly influenced by dietary treatments (P<0.05). The dressing percentage of 41.89% was recorded in T2 while the lowest of 38.67 was recorded in T1. There was no significant difference (P>0.05) in offal/live weight (%) and shell/live weight (%) of the snails in all the treatments. The results of chemical composition of the foot (fleshy part) show that the crude protein of the meat was relatively similar across the treatments (P>0.05). Based on the present results of the weight gain, feed efficiency, dressing percentage and chemical composition of the meat, quality protein maize is nutritionally efficient and better than normal maize in the diet of growing snails.
Key words: Dressing percentage, feed utilization, quality protein maize, shell growth, snails