SUBSTITUTION OF COTTONSEED MEAL FOR MARINE ANIMAL PROTEIN IN DIETS FOR PENAEUS-VANNAMEI

Solvent-extracted cottonseed meal was used in shrimp Penaeus vannamei diets at levels of 0, 13.3, 26.5, 39.8, 53.0 and 66.3%, substituting o n an equal nitrogen basis for 0, 20, 10, 60, 80 and 100% of animal pro tein mix (53% menhaden fish meal, 34% shrimp waste meal and 13% squid meal). The feeds were formulated to contain 32% crude protein and 3,10 0 kcal metabolizable energy/kg. Each diet was fed to juvenile shrimp t o satiation four times daily for 8 wk. Shrimp fed the three lowest die tary levels of cottonseed meal (0, 13.3 and 26.5%) had similar weight gain, feed consumption and survival. The performance of shrimp was adv ersely affected when diets containing more than 26.5% cottonseed meal, or 1,100 ppm free gossypol, were fed. Shrimp fed the diet with 39.8% cottonseed meal or 1,600 ppm free gossypol had depressed weight gain, reduced feed intake and high mortality. The groups receiving the two h ighest dietary levels of cottonseed meal lost weight by the end of wee k 4 and all shrimp in these treatments died within 6 to 8 wk. These ad verse effects were probably due to the toxicity of free gossypol. Shri mp appeared to accumulate gossypol in the body as evidenced by light y ellow-green coloration in shrimp fed diets containing cottonseed meal.