Effect of soybean meal replacement by cottonseed meal and iron supplementation on growth, immune response and resistance of Channel Catfish (Ictalurus puctatus) to Edwardsiella ictaluri challenge

摘要: Abstract Three basal diets containing 0%, 27.5% and 55.0% solvent-extracted cottonseed meal (CSM) as replacements of 50% 100% soybean (SBM) on an equal nitrogen basis were each supplemented with three levels iron (40, 336 671 mg/kg) from ferrous sulfate heptahydrate (3×3 factorial experiment). Each diet was fed to juvenile channel catfish in triplicate aquaria twice daily apparent satiation for 10 weeks subsequent determination growth response, hematology, specific non-specific immune mortality following Edwardsiella ictaluri challenge. Fish CSM a replacement SBM had improved weight gain (WG) feed efficiency ratio (FER). Total by decreased WG, intake (FI) FER. cell count (TCC), red blood (RBC), hematocrit (Ht) hemoglobin (Hb) not affected dietary CSM. Iron supplementation significantly TCC RBC maximum values these parameters obtained at mg iron/kg diet. However, Ht Hb increasing supplemental iron. Values TCC, the interaction between For fish 0% (SBM-based diets), increased linearly When or higher, sufficient hematological values. Macrophage chemotaxis presence exoantigen higher compared those lower diets. Agglutinating antibody titers also CSM, but did differ Dietary iron, interactions no effect macrophage titers. Cumulative 15 days post-challenge SBM-based (0% CSM) 54.4% 35.0% 21.6% diets, respectively. No differences observed among CSM-containing supplementation, post-challenged fish.