UTILIZATION OF CORN PROTEIN WITH YEAST AS A PROTEIN SOURCE IN PRACTICAL DIETS FOR PACIFIC WHITE SHRIMP Litopenaeus vannamei

Two growth trials were conducted to evaluate the use of corn protein with yeas (CPY,  NexPro, Flint Hills Resources, Wichita, KS) a novel co-product of the dry grind ethanol process, in practical shrimp feed formulations. In trial 1, four experimental diets were formulated with increasing levels of CPY (0, 10, 20, and 30%). Juvenile shrimp 1.24 g were stocked into 16 tanks (650L) with 30 shrimp/tank. In trial 2, five diets were formulated with inclusions of 0, 6, 12, 18, and 24% CPY. Juvenile shrimp 0.25g were stocked 10 per tank in 80 L tanks with four replicates per treatment. In both trials, CPY replaced a combination of fish meal and soybean meal using corn starch as a filler to produce iso-nitrogenous and iso-lipidic diets. Treatment diets were fed four times per day for 6 weeks. At the end of each experiment, shrimp were counted and group weighed. In trial 1, significant depressed growth of shrimp was observed when 20 and 30% CPY were incorporated in the diets. In trial 2, the treatment containing 6% CPY exhibited improved growth performance, however was only significant compared to the 24% CPY diet (P < 0.05). Based on current results an upper limit of 18% of the diet should be recommended in shrimp feed formulation. The reduced performance at high levels of inclusion could be due to a number of factors which should be investigated. Results in the present study demonstrated that CPY is a good protein source and can be applied as a protein source in practical shrimp feeds.