Evaluation of Channel Catfish Feeds in Long-Term Pond studies and Short term Aquarium Studies

Abstract

Responses of two sizes; 3 g and 60 g channel catfish (Ictalurus punctatus) to five commercial feeds (1, 2, 3, 4 and 5) and a negative control (contained low quality plant protein) were evaluated in earthen ponds and in glass aquaria, respectively. The commercial feeds were prepared from closed formulas but estimated to contain 32% crude protein, approximately 2.5 Kcal/g of digestible energy. Growth rate of fish fed feed 1, 2 and 3 were higher than those of fish fed feeds 4, 5 and the negative control in both ponds and aquaria (P<0.05). There were no significant differences in weight gains among fish fed feed 1, 2 and 3 or among fish fed feeds 4, 5 and the negative control in the ponds (P>0.05). However, in the aquaria, fish fed feed 2 gained more weight than fish fed the other feeds, and fish fed feed 5 and the negative control grew less than those fed feed 4 (P<0.05). Feed conversion ratios for fish fed in ponds were higher than those for fish fed in the aquaria except for the negative control. The correlation in weight gain between fish fed feeds in ponds and aquaria was 0.73 (P<0.05). The agreement in weight gain between ponds and aquarium was high for the good quality feeds but poor for the low quality feeds. There was no correlation in feed conversion ratio between fish fed in ponds and aquaria (P>0.05). The results indicate that aquarium studies are more sensitive than pond studies for evaluating nutritional qualities among practical diets. However, natural food from the pond can improve productivity of poor quality feeds.