February 15-18, 2009 Washington State Convention Center Seattle ...

NOVEL COMPOUNDS AND OPPORTUNITIES FOR RENDERED ANIMAL PROTEINS IN
AQUACULTURE FEEDS
Sergio F. Nates, PhD. and Dominique P. Bureau, PhD
Fats and Proteins Research Foundation, Inc.
Alexandria, Virginia USA
Alternative sources for diets for aquaculture species are by-products produced by the inedible rendering industry, such as poultry
meal, blood meal, meat and bone meal, hydrolyzed feathers and many others. Rendered animal proteins are especially valuable
in the context of fishmeal replacement. Formulating low fish meal feeds requires the use of combinations of economical
ingredients since most feedstuffs have been shown to have significant limitations and cannot be used individually at very high
levels in the diet of most fish species. Rendered proteins are consequently very valuable for the formulation of cost-effective,
low fish meal aquaculture feeds. A large number of studies have shown that the quality of these ingredients has considerably
improved over the past two or three decades. Today, rendered animal proteins often prove to be the most cost-effective feedstuffs
when comparison is done on a level playing field, for example, on a digestible protein basis. The high nutrient density
(high protein, high fat, low carbohydrate) of “modern” shrimp and fish feeds leaves very little room for economical ingredients
with low protein and digestible energy contents (e.g., cereal grains, field pea, canola meal, soybean meal, etc.). The high
digestible protein and energy contents of most rendered animal protein ingredients makes them useful for the formulation of
low fishmeal, high nutrient density fish feeds.
Small peptides play numerous roles in the biology of aquatic species and hydrolyzed, rendered proteins seem to have opportunities
in the currently hot area of bioactive peptides. Numerous researchers have discovered that when certain proteins are
hydrolyzed in just the right way, the products will include one of these small peptides that have powerful physiological effects.
Recently, the research group of Chen (2007), a member of the Animal Co-Products Research and Education Center (ACREC),
a research center funded by the Fats and Proteins Research Foundation has attempted to produce bioactive peptides from rendered
protein such as collagen. In the preliminary research, some bioactive peptides have been screened and identified using
various chromatographic techniques and confirmed with different in vitro antioxidant bioassays. The solid data suggests that
one of these peptides could compete as a natural alternative to the popular synthetic antioxidants BHA and BHT, widely used
in the aquaculture feed manufacturing industry. In another study, we have quantified the nucleotide content of several rendered
animal protein ingredients. The idea is to identify how rendered animal proteins can be useful in improving the nucleotide
content of diets for first-feeding Atlantic salmon. Diets can then be used to enhance the growth and gut development of Atlantic
salmon larvae.
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