Effect of adding cottonseed meal or cottonseed flour to rations for Nile tilapia (Oreochromis niloticus) broodstock

This experiment was conducted to evaluate the effect of cottonseed meal and cotton seed flour on the reproductive behavior and on the testis activity of Nile tilapia broodstock. Twenty-five fishes were fed diets containing 0, 2, 4 and 6% ground cottonseed flour and 24% cottonseed meal (CSM). The reproductive behavior of the fishes was daily observed and the nest construction, courtship and spawning were evaluated. At 90 days, the males gonads were microscopically evaluated. The control group (soybean meal) showed higher number of spawning, The fishes fed diets with cottonseed flour or cottonseed meal, despite of had not presented the same number of spawning, showed nest construction and courtship. The histology analysis of the testis indicated that the addition of 24% of cottonseed meal or 2% or higher of cottonseed flour affected the testis activity. The gossypol present in the cottonseed flour or cottonseed meal had a negative effect on the gonads of these animals.