Evaluation of two shrimp by-product meals as protein sources in diets for Penaeus vannamei

Shrimp by-product meals from the Mexican Gulf coast (heads and hulls) (GM) and from the Pacific coast (heads) (PM) were prepared and evaluated as protein sources for juveniles of Penaeus vannamei (0.209 g average weight, 0.012 s.d.). Fish meal and soybean meal in the control diet were replaced by the shrimp by-product meals to obtain isoproteic and isolipidic diets. The shrimp by-product meals were included at dietary levels of 3, 6 and 18%. Each diet (control, PM3, GM3, PM6. GM6, PM18, GM18) was tested in three replicate groups of 15 shrimp during a 28-day ad libitum feeding study. Survival rates ranged from 96 to 98%, and growth rates of shrimp fed the diets were about 360% for the control and 3% level diets, 500% for the GM6 and PM6 diets, 590% for diet GM18 and 730% for diet PM18. A highly significant correlation between the final weights and shrimp by-products meal dietary levels ( P