EVALUATION OF 2 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 evaluat ed as protein sources for juveniles of Penaeus vannamei (0.209 g avera ge 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 dietar y 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%, an d 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 GM 1 8 and 730% for diet PM18. A highly significant correlation between t he final weights and shrimp by-products meal dietary levels (P<0.001) indicated a positive dose-response relationship. Final weights were si gnificantly higher for shrimp fed the 6% dietary levels than those fed the control and 3% diets. At the 18% level, PM performed better than GM (P<0.05), probably due to a better source or process. Feed conversi on improved from about 2.1 for the control and 3% diet groups to 1.3 f or the PM 18 fed group. The improvement in feed conversion compensated for the increase in cost of the diets due to the use of shrimp by-pro duct meal, and resulted in a 36% lower contribution of feed ingredient s in the shrimp production cost.