PROTEIN AND ENERGY REQUIREMENTS OF AFRICAN GIANT LAND SNAIL (Achatina achatina)

Thesis Abstract

A 16-week study was conducted to investigate the effect of dietary protein and energy levels on the growth performance of African giant land snail (Achatina achatina). Two hundred and forty eight weeks old African giant land snails were used for the study. The snails were randomly divided into 16 groups of 15 snails each. The groups were randomly assigned to 16 diets in a 4 x 4 factorial arrangement involving four levels ((18%, 20%, 22%, and 24%) of protein and four energy levels (2.6, 2.8, 3.0 and 3.2Mcal/kg ME). Each treatment was replicated 3 times with 5 snails per replicate. Results showed that while body weight gain, feed intake, protein efficiency ratio and carcass yield were significantly (P < 0.05) increased at the 24%CP and 3.2Mcal/Kg ME levels, FCR and cost of feed per kg weight gain were decreased(P < 0.05). There were significant (P < 0.05) interactions between protein and energy levels on final body weight, average daily weight gain, average daily feed intake, feed conversion ratio, protein efficiency ratio, shell length, shell width, feed cost per kg weight gain and carcass yield. Feed intake was significantly (P < 0.05) decreased at the 3.0 Mcal/kg ME and 18%CP levels, and at the 3.2 Mcal/kg ME and 18% CP levels; FCR values were decreased(P < 0.05) at the 3.0 Mcal/kg ME and 24 %CP levels, and at the 3.2 Mcal/kg ME and 24% CP levels; PER was enhanced (P < 0.05) at the 24 %CP level and at the 2.80 Mcal/kg, 3.0 Mcal/kg and 3.2 Mcal/kg energy levels; shell length was enhanced (P < 0.05) at the 3.0 Mcal/kg ME and 22% CP levels, and at the 24% CP and 3.2 Mcal/kg ME levels; shell width was enhanced (P < 0.05) at the 3.0 Mcal/kg ME and 24% CP levels, and at the 24% CP and 3.2 Mcal/kg ME levels. Feed cost per kg weight gain was significantly (P < 0.05) reduced at the 24% CP and 3.2 Mcal/kg ME levels. The results obtained in the present study show that the dietary protein and energy levels of 24% and 3.2Mcal/kg ME are adequate for the growth of African giant land snails (Achatina achatina) in the humid tropics.