Substitution of Golden Apple Snail Meal for Fishmeal in Giant Freshwater Prawn, Macrobrachium rosenbergii (de Man) Diets

Abstract

Substitution of golden apple snail meal for fishmeal in giant freshwater prawn, Macrobrachium rosenbergi (de Man) diets was conducted by CRD with 5 treatments and 3 replications. The study was divided into two trials. Firstly, the pepsin digestibility of raw material and snail meal substitution for fish meal diets was investigated. The results indicated that the protein digestibility of diets containing snail meal were decreased (p<0.05) by increasing percentage of snail meal ( from 0 to 100%). The percentages of digestibility were 82.86 and 74.80% for 0 and 100% substitution, respectively. Secondly, the growth performance and feed efficiency were conducted on giant freshwater prawn fed with isonitrogenous (34±1% CP) and isocalorics (3,100±100 DE kcal/kg) diets containing 0, 25, 50, 75 and 100% golden apple snail meal substitution for fish meal. The results indicated that there were no significant difference (p>0.05) on growth performances and feed efficiency during the first two month while these values were significantly different (p<0.05) in the third month. Therefore, snail meal can totally substitute for fishmeal in a short period not longer than two months. For practical diet, snail meal can substitute for 25% of protein in fishmeal or 8.75 % of snail meal by weight. Moreover, the maximum level of snail meal substitution for fishmeal in giant freshwater prawn diet should not exceed 50% of protein in fish meal or 17.5 % of snail meal by weight.