Soybean Meal-Aquaculture

Japanese research also addressed the environmental problems of phosphorus and nitrogen levels in aquaculture operations. A commercial fishmeal-based diet with 1.87% total phosphorus and 0.82% available phosphorus was used as a reference diet. Five experimental diets were formulated containing 5-15% fishmeal, 10-20% soy protein concentrate, 2-8.5% defatted soybean meal and 3-5% corn gluten meal. These diets contained total phosphorus levels between 1.04-1.29% and 0.62-0.63% available phosphorus. The diets were fed to 3.4-gram carp for ten weeks. The feed utilization efficiencies were not different between the control diet and diets containing 10-15% fishmeal. Protein efficiency ratio, phosphorus absorption and retention were higher for the experimental diets. Total phosphorus and nitrogen loading (kg/ton production) for the experimental diets ranged from 7.1-8.9 and 36.1-41.3, respectively; compared to values of 15.2-48.1 for the control diet. These results indicate that formulating diets to meet the nutritional requirements of fish without wasteful excesses will support commercial production and feed utilization efficiencies, while minimizing environmental concerns of phosphorus and nitrogen loading.

Jahn, P. and co-workers. 2003. Improved carp diets based on plant protein sources reduce environmental phosphorus loading. Fisheries Sci. 69(2):219-225.