EFFECTS OF DIETARY-LIPID ON THE HEMATOLOGY OF CHANNEL CATFISH, ICTALURUS-PUNCTATUS

Juvenile channel catfish were fed diets containing either soybean oil, menhaden oil, beef tallow, or a combination of these three lipid sour ces. After 90 days, total erythrocyte, leucocyte, and thrombocyte coun ts, hematocrit, mean corpuscular volume, plasma recalcification time, erythrocyte osmotic fragility, total serum iron, and iron-binding capa city were measured. Total erythrocyte counts, leucocyte counts, and me an corpuscular volume were not significantly different (P < 0.05) amon g dietary groups. However, fish fed the menhaden oil diet had signific antly lower (P < 0.05) hematocrits, higher thrombocyte counts, and hig her serum iron concentrations. They also had the highest concentration of n-3 fatty acids in the pronephros tissue and their erythrocytes we re the least susceptible to osmotic lysis. Catfish fed the beef tallow diet had the lowest level of n-3 fatty acids in pronephros tissue and their erythrocytes were the most susceptible to osmotic lysis. Result s suggest that dietary lipids affect several hematological factors of cultured channel catfish.