New research reveals the added value of feeding wheat to pigs

Kansas State University (KSU) researchers and representatives of Kansas Wheat have published updated findings on the value of feeding wheat to pigs.

On June 14, the KSU Research and Extension news service released findings showing wheat can be used at a similar rate as corn in areas where wheat is available, without a major decrease in the diet energy density.

According to KSU Swine Specialist Joe DeRouchey, this is good news for swine producers and wheat growers.

“Our data collected from 2014-20 suggests wheat’s mean energy content is 99 percent and 98 percent of corn for digestible energy and metabolizable energy, respectively,” says DeRouchey.

“The use of wheat coproducts for the milling industry is a common practice in feeding livestock,” he continues. “For wheat, there are many different classifications of coproducts, such as wheat middlings, wheat millrun, wheat shorts and wheat red dog.”

KSU partnered with Kansas Wheat to provide an update about the nutritional value of wheat and wheat coproducts.

Aaron Harries, vice president of research and operations for Kansas Wheat, states in the press release, “Wheat milling coproducts – including bran, middlings and shorts – provide good nutritional value. In particular, these products have high phosphorus content, which results in less supplemental phosphorus in the diet and reduced costs for the producer.”

Harries notes the updated findings on feeding wheat to swine “provides valuable new information for swine feeders and allows farmers to consider swine feeding as an alternative marketplace for their wheat.”

Nutritional properties of wheat

According to the research, wheat is a major cereal grain utilized in swine diets across the world and typically serves as a main cereal grain in Canadian, European and Australian swine diets. 

Although wheat is not as prevalent in U.S. swine diets, it can still be incorporated, depending on availability and cost. 

Wheat contains higher levels of crude protein (CP) and amino acids (AA) compared to most other cereal grains which allows for less soybean meal presence in the diet to meet the pigs AA requirement, DeRouchey explains.

The report notes wheat’s standardized ileal digestibility (SID) of CP and AA is similar to corn but greater than barley and sorghum and has a particularly high tryptophan (Trp) content which results in less feed grade Trp needed to be supplemented to meet the pig’s requirements.

The research shows wheat has a lower energy density compared to corn but is higher in energy than other cereal grains and higher in phosphorus (P) and digestibility of P compared to corn.

Therefore, less supplemental P is needed in wheat-based diets compared to diets based on other cereal grains.

It was also discovered grinding wheat to a finer particle size leads to linear improvements in feed efficiency but heat particle size is generally recommended to not fall below 500 micrometers (μm) for swine diets.

Wheat tends to flour when ground too finely resulting in reduced feed intake, stomach lesions and dust accumulation, states the new research study.

Coproducts

According to DeRouchey, wheat coproducts are produced from the flour milling industry and can include wheat bran, wheat middlings, wheat millrun, wheat shorts and wheat red dog. 

Each coproduct is classified based on the combination and concentration of wheat bran, germ and residual endosperm to comprise each coproduct.

The Association of American Feed Control Officials classifies wheat bran as the coarse outer covering of the wheat kernel as separated from cleaned and scoured wheat in the usual process of milling. 

Wheat middlings, wheat millrun, wheat shorts and wheat red dog are produced when wheat bran is combined with wheat germ, flour and some offal from the “tail of the mill” and are classified based on crude fiber (CF) content and must contain no more than four percent CF, the researchers report.

They note wheat bran, middlings and millrun have a high P content, and incorporating any of these coproducts may result in less supplemental P in the diet which can help reduce diet costs. 

However, wheat shorts and red dog are lower in P than other wheat coproducts and are more similar to conventional wheat.

DeRouchey explains wheat bran has the lowest digestible energy (DE) and metabolizable energy (ME), whereas wheat red dog has the greatest DE and ME.

According to the research study, wheat coproduct inclusion in swine diets will reduce the energy density due to fiber concentration. 

The growth of nursery and finishing pigs will decrease unless other energy sources such as fat are added to the diet to maintain energy concentration.

The researchers note wheat shorts and red dog have lower fiber and higher energy due to increased starch levels and can be incorporated into diets without impacting pig growth, but in sows, wheat coproduct application may be most beneficial in gestation.

It was also discovered high fiber ingredients are gaining attention because of their ability to potentially provide gastrointestinal benefits. 

The inclusion of wheat coproducts in nursery diets was observed to improve fecal consistency, antioxidant capacity, gut morphology and reduce pathogenic bacterial populations.

Wheat coproducts have also been found to increase the abundance of bacteria involved in short-chain fatty acid production, antioxidant function, immune response and lactic acid production of growing pigs and sows.

Off-quality utilization

Off-quality wheat, which cannot be used by the flour milling industry, can be utilized in swine diets but this type of wheat is often associated with physical abnormalities or contamination affecting the nutritional value compared to regular wheat, the research team reports.

These products include sprouted wheat, low test-weight wheat and mycotoxin-contaminated wheat.

“Even if wheat is not used as the main cereal grain in a swine diet, it can be incorporated into diets as a pelleting aid,” DeRouchey says.

Pelleted wheat diets have been found to have significantly greater pellet durability index – as much as 33.1 percent compared to corn-based diets.

The two organizations have published the updated research information which is now available online at ksre.k-state.edu.

Melissa Anderson is the editor of the Wyoming Livestock Roundup. Send comments on this article to roundup@wylr.net.