Does distiller’s dried grains with solubles improve your pigs’ gut health? The final jury is still out, but there are some positive signs as University of Minnesota researchers are working to find out what compounds in DDGS are helping provide such benefits. More specifically, they are focusing on the solubles fraction of DDGS. A research team led by Jerry Shurson, animal scientist, at Minnesota, showed that adding 10 percent DDGS to typical corn/soybean meal, grow/finish diets is effective in reducing the length, severity and prevalence of lesions caused by ileitis in a moderate disease challenge.
As a result of the positive grow/finish response, the researchers started another project to test solubles fractions of DDGS in weaned-pig diets. Distiller’s dried grains with solubles is made up of a grain fraction and a solubles fraction. The researchers want to determine whether the compounds that provide the gut-health benefits are found in these fractions.
“We focused on the solubles fraction and further separated it into a high-fat, ‘yeast-cream’ fraction, and a residule-solubles fraction,” says Shurson.
During the study, researchers utilized 560 crossbred barrows weaned at 17 days of age for a six-week trial. They were split into pens with 10 pigs each.
Researchers fed the various pig groups a diet containing one of three new distiller’s byproducts (spray-dried distiller’s solubles, spray-dried yeast-cream and spray-dried residual solubles). Using a base control diet, researchers looked at three more diets, by adding one of the following combinations: control plus carbadox, control plus 6 percent spray-dried porcine plasma, and control plus carbadox and the plasma feed. These six diets were feed for the first 10 days after pigs were weaned. Common diets were fed during phase II (days 10 to 21) and phase II (days 21 to 42).
One pig from each pen (a total of 56 pigs) was slaughtered 10 days into the trial to identify the dietary effects on gut morphology. Measurements were taken at 25 percent, 50 percent and 75 percent of the small intestine length. Researchers also collected blood samples to measure acute-phase protein and insulin-like growth factor-1 concentrations. These results helped researchers determine the pigs’ gut health and immune-system status.
Still, the most important part of the trial was measuring pig performance, says Shurson.
Results indicate that pigs fed the spray-dried porcine plasma and carbadox diet had higher average daily gain for the first 10 days after weaning compared with pigs fed the other diets.
However, while average daily gain wasn’t affected by the dietary treatment during phase II, phase III and overall, pigs fed the distiller’s solubles and residual-solubles
diets had greater gains in growth rate during phase II and III, compared with the other diets.
Pigs fed the spray-dried residual-solubles diet and the porcine plasma and carbadox diet had longer villi and greater villi height:crypt depth ratio in the upper 25 percent of the small intestine compared with pigs fed the other diets. Shurson notes that long, healthy villi help the pigs get as much nutrition out of feed as possible. This may have contributed to increased growth rates during phase II and phase III.
The findings also suggest that feeding diets containing spray-dried distiller’s solubles, yeast cream and residual-solubles fractions provide similar performance to pigs fed diets containing carbadox and porcine plasma. These pigs did, however, have lower average daily gain and average daily feed intake compared with pigs fed diets containing porcine plasma.
Once the pigs were slaughtered, researchers found that pigs fed the residual-solubles diet had longer villi in the small intestine compared with pigs fed diets containing carbadox.
Corn condensed distiller’s solubles may contain “unidentified growth factors” that improve growth performance and stimulate feed intake, adds Shurson. However, these have not been isolated or identified.
“We also conducted a nutrient-balance trial to determine whether we compromise protein retention, energy or digestibility by adding these distiller’s solubles fractions to the nursery-pig diet,” says Shurson. “It turned out, we had no problems with these factors.”
“During the feeding trial, the diet containing plasma and carbadox beat all the others. But pigs fed spray-dried distiller’s solubles fractions did quite well,” notes Shurson. “We got positive responses for some criteria, in favor of one or more of the distiller’s products, but not for all of the criteria we measured.”
One interesting finding he points out, is that pigs fed the diet containing residual-solubles fractions did well as far as gut health. It did not, however, result in improved performance during the first 10 days after weaning.
However, pigs fed the residule-solubles diet had a carryover effect in the later nursery phases. Those pigs had a greater improvement in feed consumption and growth rate than pigs fed the plasma and plasma-plus-carbadox diets. This suggests that there must be something going on that may provide gut-health benefits after this distiller’s fraction is fed for a period of time, notes Shurson.
Overall, these studies are giving researchers more insight into DDGS and its compounds that provide performance benefits. “We know from this work that it appears there’s something in the residule solubles that supports the theory that DDGS contains some unidentified health factors,” says Shurson.
He also notes that this work is creating an an opportunity for ethanol plants to manufacture a dried-solubles product that will work effectively in nursery-pig diets.
Incorporating DDGS in Swine Diets
If you’re planning to use distiller’s dried grains solubles in any of your swine diets, there are a few things to consider, according to Bob Thaler, swine nutritionist, South Dakota State University.
Compare total versus digestible amino acid levels:
Maximum DDGS inclusion rate is 10 percent if diets are formulated on a total-amino-acids basis.
DDGS inclusion rates can be much higher if the diets are formulated on a digestible-amino-acids basis.
Consider total versus available phosphorus.
Formulating diets on an available-phosphorus basis increases economic benefit and reduces the phosphorus content of manure.
Identify your supplier of DDGS and ask him for a complete nutrient profile of the product you’re purchasing so you know what you’re getting. (Check the nutrient profile at www.ddgs.umn.edu)
200 pounds of DDGS and three pounds of limestone replaces 178 pounds of corn, 19 pounds of 46 percent soybean meal and six pounds of dicalcium phosphate.