Ensiling of Golden Apple snails (Pomacea canaliculata) and growth performance of African catfish (Clarias gariepinus) fingerlings fed diets with raw and ensiled Golden Apple snails as protein source

Abstract

The influence of ensiling Golden Apple snails (GAS) on nutritional and biochemical traits, and the growth performance of African catfish (Clarias gariepinus) fingerlings fed diets where fish meal was replaced with raw or ensiled GAS as protein source was studied. Raw GAS was ensiled without (control) and with addition of citric acid or sugar cane molasses. The dry matter (DM) content in ensiled GAS decreased (P<0.05), and the pH value and ammonia nitrogen content increased (P<0.05), with time of ensiling on all treatments with the largest effects in the control and in the treatments with lowest inclusion of citric acid and sugar-cane molasses. Crude protein content decreased numerically with time of ensiling on all treatments. It was only the treatments with high addition of sugar cane molasses (>15% in DM) that maintained a brownish-yellow colour and a nice smell for the whole ensiling (28 d) period. A control diet with fish meal and three experimental diets, where fish meal was replaced with raw or ensiled GAS, were formulated and fed to African catfish fingerlings. GAS was ensiled with 5% citric acid or 20% sugar cane molasses. The growth performance and feed consumption was recorded for a period of 6 weeks. There were no differences (P>0.05) in growth performance, feed and protein utilization, and whole body composition between treatments. In conclusion, protein from raw and ensiled GAS can completely replace fish meal in diets for African catfish fingerlings under tropical conditions without negative effects on growth performance and feed utilization.