Alternative Ingredients to Fish Meal in Aquatic Feed
Fish meal has been used as a main ingredient in aquatic diets, poultry and swine feed. High quality fish meal can supply a good part of the protein, amino acids and energy requirements for fish. With the steady growth in aquaculture, the captured fish will not be able to sustain the current usage level of fish meal.
For many countries, the availability of high quality fish meal and its high cost have encouraged the search for alternative ingredients.
According to Dr. Mavromichalis in his article published in the following link, the price of fish meal has increased from about $480 per metric ton in 2001 to over $2,000 dollars currently, with no sign of leveling off. Click the following to see the full article: Fish meal prices to remain prohibitively high for pig, poultry feeds.
The United States Soybean Export Council (USSEC) has published several papers on the potential for using soy products, such as soy protein concentrate, solvent extracted soybean meal and full fat soy, as a partial or total replacement of fish meal (www.soyaqua.org). Supplementing the diet with fish oil may enhance the palatability of the diet.
Soy protein is an excellent source for the required amino acids in aquatic feed, however, it is deficient in Methionine and Cystine, and to some degree Lysine, as compared with fish meal. For this reason, supplementation with the above mentioned amino acids is needed. The defatted soy products lack the necessary fatty acids and lecithin required by fish. Extruded full fat soy and partially defatted soybean meal (ExPress® soybean meal) may fill that void by not only providing the protein and energy but with lecithin and essential fatty acids
On the other hand, co-extruding the soy product with secondary resources such as fish, poultry, swine or ruminant by products will complement the soy protein nutritional profile and provide a substantially cheaper source of complimentary protein and energy.
High shear extrusion has been used to achieve this goal with huge success. The extrusion technology of secondary resources from the animal and the food industry will provide many producers with the means of providing high quality extruded feed ingredients alternative to fish meal for aquatic and terrestrial animals.
The reference below contains more information on alternative ingredients through co-extrusion.
“Extrusion of Alternative Ingredients: An Environmental and a Nutritional Solution”. 1996 J. Appl. Poultry Res. 5:395-407