Effects of Dietary Choline, Pantothenic Acid and Vitamin C on the Serum Complement Activity of Red Sea Bream

Red sea bream Pagrus major were fed on the purified diets containing different levels of choline, pantothenic acid or vitamin C for 2-6 weeks, and the effects of these vitamins on serum complement activity and natural hemagglutinin titer were examined.The dietary requirements of red sea bream for choline chloride and Ca-pantothenate were estimated to be about 50mg and 1mg per 100g diet, respectively, on the basis of growth and feed efficiency. The dose levels of 0-400mg choline chloride/100g and 0-15mg Ca-pantothenate/100g diet did not affect the complement activity in fish, but higher levels of 800mg choline chloride/100g and 28mg Ca-pantothenate/100g diet significantly enhanced the complement activity. These results indicate that dietary supplementation of 15 to 30 times the minimum requirement of choline chloride or Ca-pantothenate is necessary for the enhancement of the complement activity. There was no difference in the complement activity between fish fed on the diets with and without 100mg vitamin C per 100g diet. However, the group fed on the diet containing 100mg of vitamin C showed a significantly higher natural hemagglutinin titer.