Swine producers concerned about continuing high grain prices might want to consider using field peas as a partial substitute for soybean meal or corn in swine diets. Research coordinated by an Iowa State University (ISU) Extension swine program specialist showed this substitution is well tolerated by pigs and can be a more economical choice.

Tom Miller said the research started in 2005 after an inquiry from a southeast Iowa producer. The initial study, funded by the Leopold Center for Sustainable Agriculture at ISU and through the USDA's Sustainable Agriculture Research and Education program, included both raising field peas and using the field peas in swine diets.

Dr Miller said: "We looked at the growth of different field pea varieties in small field plots of 20 to 70 acres in southeast Iowa. We also tested the use of field peas in diets of a hog operation near Keota and at the ISU Swine Nutrition Farm. We hoped this would lead to developing an economical supply of these feedstuffs to use in pork production."

The feed trial results showed that it is possible for swine producers to increase their profits by using field peas because they provide nutrients comparable to corn and soybeans at a lower cost than those grains, according to Dr Miller.

He explained: "Field peas are a good source of lysine, and they're high in fibre with low levels of a trypsin inhibitor. Typically, they're fed raw and can be used for sows, weaned and finishing pigs."

Wider adoption of field pea use by Iowa producers hinges primarily on access to adequate quantities of the crop. The early field tests showed that field peas cannot withstand Iowa's summer heat and winter cold, Dr Miller said. And while double cropping is a possibility, planting one's own field pea crop currently does not necessarily offer an economical advantage to Iowa producers.

He added: "The next step is to find a profitable cropping system in order to be able to utilise the potential of the field pea, which includes research on modifying the peas to survive Iowa's climate."

Another option for producers who want to incorporate field peas in their swine diets is to buy the peas from locations with more conducive growing conditions such as North Dakota and Canada.

In a presentation, Dr Miller presented some early results from his work on field peas for pigs, he explained that peas are widely used in feed for pigs in Europe diets, and increasingly in Canada. Compared to soybean meal, field peas contain less fat, moderate levels of carbohydrates and protein and more fibre.

Chemical composition of two varieties of spring-planted field peas in Iowa (2005)

Nutrient profile of field peas compared to maize and soybean meal (44 per cent protein)

The amino acid profile of field peas worked extremely well with distillers dried grains with solubles (DDGS), according to Dr Miller. DDGS from an ethanol plant contains 0.76 per cent lysine, 0.85 per cent methionine plus cystine, 0.225 per cent tryptophan and 1.01 per cent threonine, he said.

Dr Miller concluded: "Ultimately, the cost of obtaining field peas, whether grown locally or imported from other locations, will be a determining factor in Iowa producer use. The positive nutrient and palatability aspects are well documented."

May 2010