Ethanol byproduct can hurt pork quality: U.S. experts
Published:May 7, 2007
Source :Reuters
Hogs that are fed high amounts of an ethanol byproduct that is a cheap alternative to corn could have excessive fat levels and the quality of certain pork products could be lowered, university scientists said.
Demand for distillers grain as a feed alternative has picked up following the rise in corn prices to 10-year highs this year, which has been fueled by the ethanol industry's voracious appetite for the grain.
Dry distillers' grains with solubles, or DDGS, can be used as livestock feed and has been touted as a potentially inexpensive option for producers who are being priced out of the corn market by companies that use corn to make ethanol.
But the scientists said replacing large amounts of corn with DDGS in swine diets adds excessive unsaturated fatty acids. Although, adding some DDGS, which is produced in making ethanol, could be acceptable, they said.
"What we've found is that replacing 10 to 12 percent of the corn with DDGS in pig diets is doable," said Mickey Latour, a Purdue University Extension animal scientist. "For gilts it may be more in the range of 6 to 8 percent, because gilts tend to have softer fat relative to barrows."
But they said adding too much DDGS could be undesirable.
High levels of unsaturated fatty acids affect the appearance of bacon and sausage, and could affect taste, Latour said.
In addition, the balance of Omega-6 to Omega-3 fatty acids in the pork products are likely to be tipped toward unhealthy dietary levels, he added.
While beef cattle can consume up to 30 percent DDGS without meat degradation, the same is not true of swine. There were about 61 million head of hogs on U.S. farms as of March 30, according to the U.S. Agriculture Department.
Research by Latour and fellow Purdue animal scientists finds that the pig's unique body composition turns DDGS into soft fat at rates higher than when the pig is fed a straight corn-soybean diet.
Bacon produced from pigs fed little or no DDGS is very firm, ideal for slicing, and creates well-defined lean and fat lines. Bacon from pigs fed high levels of DDGS is flabby -- commonly shown as "bending" -- and exhibits smeared-looking fat and lean lines.
Non-DDGS sausage has a richer color and texture, while pigs fed large quantities of DDGS produce sausage that appears pale and undesirable, they said.
DDGS also affects the nutritional value of pork products, Latour said. As the percentage of DDGS fed to a pig goes up, so, too, does the ratio of Omega-6 to Omega-3 fatty acids.
Although Omega-6, or n-6, fatty acids are a necessary part of the human diet, excessive levels are believed to increase the risk of cardiovascular diseases. Omega-3, or n-3, fatty acids are known to be healthy fatty acids.
"Dietitians would recommend we consume foods with a n-6 to n-3 ratio of between 4-to-1 and 6-to-1," Latour said.
