Performance, proximate and mineral analyses of African giant land snail (Archachatina marginata) fed different nitrogen sources

Abstract

The effect of different nitrogen sources in the diets offered to caged African giant land snail, Archachatina marginata, was investigated in a six months experiment.  Four experimental diets I, II, III and IV containing soybean, fishmeal, poultry dropping and urea as the only nitrogen source, respectively were formulated.  Diet V (Pawpaw leaves) served as the control. Growth parameters (weight gain, feed intake, shell length gain and shell circumference gain), hemolymph and flesh minerals and proximate composition of the snails were determined.  Snails fed diet III (poultry droppings) recorded the highest weight gain while the snails fed diet IV recorded the least value.  Snail fed diet I had the highest feed conversion ratio (FCR}. The least FCR value was recorded for snails on diet V.  The feed intake of snail on diet V was significantly higher (p <0.05) than those of other diets. The highest shell length gain and shell circumference gain was recorded in snails fed diet III. Analysis of the Hemolymph mineral composition revealed that snails fed Diet I had the highest value for Ca2+ , Mg2+ and Fe2+ while the highest value in Na+ and Zn2+ was recorded in snails on diet V.  The chemical analysis of the flesh showed that snails fed diet V had highest value in Na+, K+, Zn2+ and Cl-while snails on diet III had the least value in Mg2+ and Cl-. Proximate analysis of the snails flesh revealed that crude protein value was least in snails fed diet IV and highest in snails fed diet III. Snails fed diet V had the highest ash content value closely followed by snails on diet I while those on diet IV recorded the least value.The result of the study showed that higher growth performance for Archachatina was favoured by diet III.   Key words: Snail, feed, proximate, nitrogen sources, diet.