Growth, parasitic infection and hematology in Colossoma macropomum Cuvier, 1818 fed diets containing Allium sativum

The aim of this study was to investigate the effects of a dietary Allium sativum (garlic) addition on growth, parasite infestation and blood parameters in Colossoma macropomum (tambaqui) using 12 net-cages (1m(3)). There were four treatments with three replicates each (15 fish per replicate). Tambaqui of 112.4g mean weight were fed for 45days with diets containing 0, 15, 30 and 45g of fresh garlickg(-1) feed. Garlic did not affect the tambaqui survival, growth, feed conversion, body condition, plasma glucose levels, total plasma protein levels or red blood cells. Total leukocyte and lymphocyte numbers decreased in fish fed diets containing 45g garlickg(-1) feed, but neutrophils decreased in fish fed diets containing 15, 30 and 45g garlickg(-1) diet, while the number of immature leukocytes increased in fish fed 30g and 45g garlickg(-1)diet. Gills in fish fed 30 and 45gkg(-1) diet had lower infestation (52% and 63%, respectively) of Anacanthorus spathulatus (Monogenea) compared to controls. The application of garlic in diets improved the response of leukocytes and enhanced the resistance to infections by monogeneans.