Improvement of Cottonseed Meal Protein with Supplemental Lysine in Feeds for Channel Catfish

Two studies were conducted to evaluate cottonseed meal (CSM) with and without supplemental lysine as a substitute for soybean meal (SBM) in catfish feeds. One study was conducted in aquaria under controlled environmental conditions with fingerling channel catfish, and the other was conducted with fish raised in 6-m3 net pens suspended in a 1.6-ha earthen pond. In each study, solvent extracted CSM was substituted for SBM on a nitrogen basis. Supplemental lysine was added to the feeds in which CSM replaced 50 and 100% of the SBM because they were estimated to be deficient in available lysine. In the aquarium study, 0, 25, 50, and 100% of the SBM was replaced with CSM. The same feeds used in the aquarium study were used in the net pen study, except that the 25% substitution was not used. Fish raised in aquaria were fed 4% body weight divided into two equal daily feedings, and those raised in net pens were fed to station once daily. Data presented herein demonstrate that channel catfish can effectively utiliz...