World aquaculture production is dominated by omnivorous fish species that live in freshwater, including various carp and catfish species. Soybean meal is a prominent ingredient used in prepared diets for these species, often constituting 50 to 60% of the total formulation. Such levels of incorporation are possible due to adequate palatability of soybean meal and its excellent nutritional value for these species, including high levels of crude protein, complementary amino acid profile and relatively high nutrient digestibility. For many omnivorous freshwater species cultured throughout the world, soybean meal has largely replaced more costly protein feedstuffs in diet formulations, such as fish meal, while maintaining optimal fish production. As a result, the cost of fish production has been reduced substantially. While aquacultural production continues to expand worldwide to meet the growing demand for seafood, the use of soybean products will play an even more important role in providing high-quality protein for various fish species.
A feeding demonstration was conducted at Thirumaniari, Tiruvaroor District, Tamil Nadu, India to compare the growth of rohu carp (Labeo rohita) grown using two different production and feeding methodologies in six 0.11-ha earthen ponds. Rohu carp of size 16 g were stocked in three ponds at 1,430 fish per pond and cultured using the ASA feed-based technology with soy-maximized, extruded feed. In the other three ponds, 12-g rohu (Labeo rohita), 12-g catla (Catlacatla), and 24-g mrigal (Cirrihinus mrigala) carp were stocked at 330, 132 and 198 fish per pond, respectively, and cultured using the traditional India National Package (NP) methodology. The NP methodology uses low density culture with nutrient addition through animal manure and low quality supplemental feeds. Rohu carp cultured using the feed-based ASA technology grew from 16 g to 477 g in 221 days and yielded an average of 6,721 kg/ha. Rohu carp cultured using the NP methodology grew from 12 g to 404 g in 264 days. Total combined yield for rohu, catla and mrigal carps from the NP ponds averaged 2,160 kg/ha. Fish grown with the ASA technology and feed yielded significantly better weight gain, health, production, FCR and economic return than fish cultured using the NP methodology. Taste tests found no discernable difference in the taste of fish produced using either culture method.