Submitted to: Annual Eastern Fish Health Workshop
Publication Type: Abstract Only
Publication Acceptance Date: February 22, 2006
Publication Date: March 28, 2006
Citation: Pasnik, D.J., Evans, J.J., Aksoy, M., Lim, C.E., Klesius, P.H. 2006. Natural content and processing of alternative protein sources: histologic effects in fingerling channel catfish (ictalurus punctatus). 31st Annual Eastern Fish Health Workshop. Charleston, SC. March 28-30, 2006. page 54. Technical Abstract: Significant effort has been made to utilize alternative protein sources like cottonseed meal (CSM) and soybean meal (SBM) to replace fishmeal in channel catfish (Ictalurus punctatus) feed. These sources are readily available and have high nutritional value, but contain anti-nutritional factors (ANF) and toxins (ex. trypsin inhibitors in SBM and gossypol in CSM) that may be detrimental to fish. We studied the effects of these factors by evaluating histopathologic changes in fingerling catfish fed diets containing various levels of CSM, gossypol-acetic acid, or SBM for 10-12 weeks. Changes associated with ANF/toxins were variable often in a dose-dependant manner, but included hepatic glycogen deposition, pancreatic necrosis, pancreatic vacuolization, loss of enterocyte supranuclear vacuolization, and pigmentation of the spleen. Processing methods commonly used to inactivate or detoxify CSM or SBM ANF/toxins in mammalian diets were also studied; iron failed to reduce gossypol toxicity and heat-treatment failed to significantly reduce trypsin inhibitor toxicity. These studies indicate that ANF/toxins naturally present in SBM and CSM may cause histologic changes in fingerling channel catfish. Further refinement of processing techniques to inactivate or eliminate these ANF/toxins and minimize their adverse effects on fish is warranted.