Light test weight grain may fit well in swine feeding programs
Contact: Bob Thaler
Phone: (605) 688-5345
Wednesday, September 24, 2008
Light test weight corn and grain sorghum can still work well in swine feeding programs.
In the past, producers have saved money using grains with lower test weights, said South Dakota State University Cooperative Extension Swine Specialist Bob Thaler.
"If the corn price is decreased, say by 15 percent, and feeding efficiency drops by about five percent, a producer will still spend fewer total dollars using light test weight grain," Thaler said. "The lower feed cost offsets the reduced efficiency, and if you can buy light grains at harvest when the dockage is greatest, you have the best chance at saving money using this feed."
As an example, Thaler said if producers can lower corn costs by 50 cents a bushel buying low test weight corn, they would lower the average swine diet cost by $14.30 per ton of feed. "The lower cost offsets the lost efficiency," he said.
Late spring planting and a cool fall may lead to lighter test weights for corn and milo this harvest season, but these feed options can still provide a viable feedstuff for swine herds.
"Mold and mycotoxin are the first concern when purchasing weather-stressed corn or milo, as they could found in these grains," said Thaler. "If they are found, use that feed only for grow-finish pigs, and at low levels. If light test weight grain is mycotoxin-free, it can be fed to all classes of swine."
Thaler said in terms of nutrition, light test weight grains would have less energy, due to lower concentrations of starch and fat. "Canadian research shows there's a 13.9 kcal/kg decrease in metabolizable energy for every pound-per-bushel decrease in corn test weight," he said. "And while light test weight grains are higher in protein, they do not necessarily have increased lysine levels."
If test weight is reduced by 25 percent or less, swine daily gain will not suffer.
"Research here at South Dakota State University, along with work done at the University of Minnesota, Michigan State University, and in Canada has shown test weight can drop as much as 50 pounds per bushel without affecting feed efficiency," said Thaler. "But once that threshold is crossed, pigs may compensate for lower energy intake by eating more feed, thus potentially impacting feed efficiency negatively."
Thaler said adding fat in the current price climate does not make economic sense. "Like any lower-energy feed, the best places to use low test weight grains are in finishing and gestation diets," he said. "But with gestating diets, it's important to be ready to increase the amount fed per day if sows are starting to lose body condition."
Another key consideration with light test weight grains is adding them to diets based on weight. "If producers do not have scales on their grinders, they may have problems adding the correct amounts of light grains," Thaler said. "Also, light test weight grains have less bulk density, so mixers may become full before the desired weight of gain added is reached."
For more information on the use of light test weight grains in swine feeding programs, ask for information at your county Extension office, or call Thaler at (605) 688-5345.
AgBio Communications Unit
South Dakota State University
ACC, Box 2231, Rm 200
Brookings, SD 57007
Telephone: (605) 688-4642
Jarett.Bies@sdstate.edu