TALKING POINT
DDGS Already a Proven Ingredient in Aquafeeds By Kurt A. Rosentrater
In recent months, the buzz has been about using various fractions from DDGS as protein ingredients in feeds for the aquaculture industry. Indeed, there are some very interesting value-added ingredients coming down the pipeline. Unbeknownst to many, however, traditional DDGS has already been proven time and again as working very well as a protein source in a variety of aquafeeds. As with any feed ingredient, though, it must be used at the proper level, and in proper combination with other ingredients as part of a complete, balanced diet. Formulations vary, depending upon the species and the age of the fish—similar to any other livestock species. A broad look at the industry and a bit of history are in order. Aquaculture is the fastest growing animal food-producing sector globally. The industry has been growing by nearly 7 percent per year for almost 40 years. In fact, it has been the only food producing sector growing at a rate greater than human population growth. Most of this growth has been outside the U.S. and, although there is considerable potential here in the U.S. for fish production, it has been slow to DDGS Inclusion in Fish Diets Landmark Studies Species Tilapia
Catfish
Rainbow Trout Prawns
DDGS (%)
Citation
19 – 29
Tudor et al., 1996
30
Coyle et al., 2004
0 – 49
Wu et al., 1996
0 – 82.23
Wu et al., 1997
100 (distillery solubles)
Kohler and Pagan-Font, 1978
100%
Tidwell et al., 2000
35
Webster et al., 1992
0 – 30
Webster et al., 1993
0 – 70
Webster et al., 1991
3.3 – 6.6 (thin stillage - wheat)
Thiessen et al., 2003
40
Tidwell et al., 1993
40
Tidwell et al., 1998
100
Coyle et al., 2003
100
Coyle et al., 2004
50 | Ethanol Producer Magazine | OCTOBER 2014
materialize. China has by far been the world’s leader in aquaculture production, but other countries around the world have also become large players, including Indonesia, Vietnam, Bangladesh and several South American countries. Even though many countries have rapidly increased production during the past decade, China is still the largest producer of fish. For a typical fish production operation, in the U.S. or abroad, feed costs represent between 40 and 70 percent of all operating costs, depending on the specific farm. Historically, fish meal has been one of the most important ingredients in aquatic diets, supplying essential proteins, amino acids, fatty acids, minerals and other nutrients. In recent years, as the demand for fish meal has grown in tandem with the growth of aquaculture, the price of fish meal has skyrocketed, hovering between $1,500 and $2,000 per metric ton for the past four years. The increases in both demand and price have propelled the search for wild marine and fisheries stocks, even though wild capture has not increased significantly for many years. A logical solution to this dilemma is to use plant-based cereal and oilseed ingredients. There are many to choose from. There are also challenges with many of these alternatives, however, including unwanted nutrients and antinutritional factors (e.g., trypsin inhibitors,
Cost vs Inclusion Rate