Effects of dietary protein and energy levels on growth and lipid composition of juvenile snail (Semisulcospira gottschei)

A feeding trial of 5 dietary protein levels (12%, 22%, 32%, 42%, and 52%) and 2 dietary energy levels (3.3 and 3.9 kcal/g diet) factorial design with three replicates was conducted to investigate the proper dietary protein and energy levels for the growth of the snail (Semisulcospira gottschei). Snails, initial averaging 37 mg, were fed the experimental diets for 12 wk. Survival of each group was all above 80% and no significant difference among treatments. Mean weight gain of the snails was improved with increasing dietary protein level up to 22% and 32% at 3.3 and 3.9 kcal/g diets (P < 0.05), respectively, and reached a plateau above these levels (P > 0.05). Mean weight gain of snails fed the 22% protein diets with 3.3 kcal/g diet was not significantly (P > 0.05) different from that of snails fed the 32% to 52% protein diets with both energy levels. Lipid content of snails fed the 3.9 kcal/g diets showed higher values than that of the 3.3 kcal/g diet at the same protein level. Snails fed the 3.9 kcal/g diets showed a tendency toward to higher in 18:1n-9, 18:2n-6, 18:3n-3, and 22:6n-3 and lower in 20:4n-6 and 22:1n-9 than those of snails fed the 3.3 kcal/g diets energy diets. The results of this study indicate that a diet containing 22% protein and 3.3 kcal/g diet with P/E ratio of 69 mg protein/kcal was recommended for snail growth.