Le calcium dans l'alimentation de l'escargot géant d'Afrique "Achatina achatina" (Linné)

Résumé

To test the effect of a calcium-based diet on growth in the snail Achatina achatina L., two experiments were carried out. In the first experiment, snails weighing a mean of 42 g at day 0 were fed with meal prepared with 15% calcium powder derived from poultry egg shell, kaolin, oyster shell or chalk. The results suggest that calcium powder from the first three sources should be used preferentially to chalk, since they are readily available, cheaper and result in better yield and growth. In a second experiment, we tested four different ways of presenting oyster shell calcium supplement to young snails. 120 one-week-old snails were weighed and equal numbers randomly assigned to the four conditions: powder mixed with cabbage and pawpaw leaves (t1); powder mixed with the litter (t2); fragments of oyster shell laid on the litter (t3) and powder alone distributed ad libitum onto a Petri dish (t4). Each treatment was replicated three times. In terms of growth (average daily gain), the highest results were obtained with t4. Digestibility coefficients for calcium from powdered oyster shell were 84%. To cover the calcium requirements of growing snails, the diet should include 15% powdered oyster shell.