Int’l - SDSU research: Adding field peas to swine rations could lower cost, phosphorous levels

Feeding field peas in swine diets could lower feed costs and lower the amount of phosphorous in manure. According to South Dakota State University associate professor of monogastric nutrition Hans Stein, field pea research at SDSU looks at the nutritional value in swine diets. "(One) way it will help producers is that they can lower the cost of feed by including field peas in their rations. Also, especially if you go to the west of here, producers have to drive quite a ways to get soybean meal," Stein said. "But they can grow their own field peas so they would save some trucking costs also, which can be a major problem if you are far from Brookings." Stein started his research at SDSU in 2000. A group of field pea growers came to him at that time to see if he would be willing to do some research with swine rations. "When they heard there was a new swine nutritionist here, they contacted me and told me that they had trouble selling their field peas to swine producers because nobody had done the research. They didn't know how much they could put in there," Stein said. Since the start of the field pea research, Stein and other swine researchers at SDSU have conducted eight experiments dealing with field peas. Some of those experiments looked at how field peas fit in the ration, how the nutrients are digested and what pigs get out of them as well as how phosphorous is utilized. Stein found that field peas in nursery diets tcan be at least 18 percent of the diet. In growing and finishing pig diets, field peas can account for 36 percent with no negative effects. A rule of thumb, Stein said, is if producers include 3 percent field peas into the diet, you take out 2 percent corn and 1 percent soybean meal. However, he said that they still need to balance the amino acids. "We have also measured the digestibility of all of the amino acids in field peas and found that for most amino acids the digestibility is very close to what it is in soybean meal," Stein said. "And, we measured the energy concentration and found that that was close to what is in corn. So if you take corn and soybean meal out and use field peas then you don't get less energy into the diet which is also important." Stein also found that phosphorous is a lot better utilized in field peas than in corn and soybean meal. "So, you will have less phosphorous in your waste stream if you use field peas compared to corn and soybean meal," he said. In the most recent field pea study, the focus was to look at the eating quality of pork from pigs fed field peas. The hogs for that study were harvested at the end of December so results from this portion of the study will not be available for a few months. Stein said they will measure everything they can measure in terms of backfat and loin eye area. Then, they plan to do fatty acid profiles and a taste panel will sample both the loins and bacons. Stein hopes to continue experiments with field peas, especially on phosphorous digestibility. Current SDSU research shows that phosphorous digestibility is twice as high or three times higher than corn and soybeans in the diet. The benefit to the swine producer of the phosphorous digestibility research is that they would not have to buy as much inorganic phosphorous to add to the diet and would see less phosphorous in manure. "They'll get less phosphorous into their manure and therefore they need fewer acres when they spread the manure so they don't have to haul it so far," Stein said. Starting in the summer, Stein hopes to start some research on field peas in turkey diets. He has a graduate student coming in with a background in poultry nutrition who he hopes will be doing some of that research. "I think we have a pretty good handle on what a (swine) producer might have if they ask what happens if we use field peas. There are still many more questions we could ask but at least they can get started now," Stein said. "I think the main thing is that nutritionally, we have found that pigs will perform exactly as well on field pea diets compared to corn/soy diets if they are balanced for all the amino acids." For more information on Stein's research, visit http://ars.sdstate.edu/swineext/swine.htm, or call him at (605) 688-5434.