Effects of fat-soluble vitamins on the growth performance, feed efficiency and histological changes of green catfish (Mystus nemurus Cuv. and Val.)

Qualitative effects of fat-soluble vitamin A, D, E and K) were studied in green catfish. The experiment consisted of five treatments with three replicates each. The feed of formula 1 was supplemented with complete vitamins while the feeds of formulae 2, 3, 4 and 5 were prepared using the same feed components and vitamins as in formula 1, except that they were deficient in vitamins A, D, E and K, respectively. The experiment was carried out for a period of ten weeks in 200-1 glass tanks. There was no significant difference in growth performance or feed efficiency among the groups (P0.05). The fish fed diet without vitamin A supplementation had the lowest survival rate. External abnormalities of fish were recorded such as hemorrhage at the fins, deformities of the barbells and fins, opened operculum, gill of paler coloration and swollen abdomen. Additionally, the fish showed behavioral changes including higher response to stimulus and sluggish swimming and remained at the corners of the tank and with lower feed susceptibility. Result of blood analysis showed lower plasma protein, hematocrit and hemoglobin than the fish fed other feeds. Histological examination showed pathological changes of the gill, liver and kidney tissue. Fish fed the feed without vitamin D supplementation developed similar abnormalities, though of less severity, is those recognized in fish fed the feed without vitamin A supplementation. The hepatosomatic index of fish without vitamin D supplementation was highest among all the treatments. No abnormality was noted in the fish given the feed containing all fat-soluble vitamins or in those without vitamins E and K supplementation throughout the experimental period.