Effects of feeding frequency, moist and dry feeds on the growth of Chrysichthys nigrodigitatus Lacépède and on pond water quality

摘要

AbstractTo examine the effects of different feeding frequencies, moist and dry feeds on the growth ofChrysichthys nigrodigitatusLacépède and on water quality of freshwater ponds, two experiments were conducted. In one experiment, fish stocked at the same densities were subjected to three different feeding regimes using equal quantities of feed. Water quality was monitored and fish growth in the different treatments was compared. To determine the effects of moist and dry feeds, fish growth and water quality in one set of ponds fed with 5 body weight of dry feed were compared to those in another set of ponds stocked at the same rate but fed with 5 body weight of moist feed. Feeding once a day produced the greatest weight gain but fish fed once on alternate days had the best feed conversion, which was associated with pond water that had the highest dissolved oxygen. This suggests that feeding once on alternate days could be adopted as a strategy for feeding fish under unfavourable conditions. Water quality of ponds holding fish fed dry feed was better than that of ponds holding fish fed moist feed, as indicated by oxygen, carbon dioxide and ammonia contents. A highly significant difference in growth (P<0.01) was found between fish fed moist and dry with feeds: fish performed better when fed with dry feed