Published Oct 4, 2018

Small Grains, Large Gains: Feeding Rye to Pigs

By Celize Christy

Rye is commonly known by farmers in the Midwest as a cover or green manure crop. A small amount is grown as a grain, and an even lesser amount is being fed to pigs. Across Europe, pig producers include rye in feed rations for their grow-finish pigs, gestating, and lactating sows. Rye has a mixed reputation due to its susceptibility to ergot, a fungus that negatively impacts pig health and performance. To combat the issue of ergot, new varieties, like hybrid rye have been developed with traits making it less susceptible to ergot toxins. Winter rye and hybrid rye have genetic differences, but are managed and planted the same way. Both are grown for grain production, forage, or as a cover crop to improve soil health.

“I’m more excited about hybrid rye, than I have been than any other product that we have, because of its potential on diversifying our landscape in the Midwest” – Mac Ehrhardt (Co-owner of Albert Lea Seed)

Hybrid Rye

A German company, KWS, has spent ten years developing hybrid rye. KWS has developed nine different hybrid rye varieties, three of which are sold in the U.S: Bono, Brasetto, and Progas. Bono and Brasetto are the two grain-type hybrids, while Progas is a forage-type hybrid.

Hybrid rye is just as cold hardy as winter rye, but higher yielding and more resistant to ergot. KWS, in the process of hybridizing rye, isolated the Rfp1 gene from an Iranian rye landrace. The Rfp1 gene ensures that hybrid rye produces twice as much pollen as open-pollinator varieties (OPV), which KWS labels as PollenPlus. Producing double the amount of pollen allows fertilization to occur in a short window of time – extremely reducing the chance for ergot to attach, thus minimizing fungal infection.

Hybrid rye is planted in the fall, vernalizes over the winter and is harvested in the summer as a grain. It has been proved to enhance water penetration and retention, reduce soil erosion, and reduce weed biomass by 65 to 90% (University of Minnesota). Growing hybrid rye lessens input costs since its large root system uses 20% less water and takes 20% less fertilizer than winter cereal rye.

Hybrid rye also helps to break resistant weed cycles, like ragweed and foxtail. With hybrid rye’s low input management and incorporation into the rotation of corn and soybeans, it helps to spread the workload across the year. Tom Frantzen (below), of New Hampton, Iowa, has been growing hybrid rye for the past few years and has seen how hybrid rye competes with ragweed – limiting the ragweed infestation in his organic crop fields. In the video below, Tom discusses how he has been feeding hybrid rye to his pigs.

Nutritional Quality and Health Benefits of Rye

Compared to other small grains, rye has higher energy and lysine concentration, but a lower protein proportion. Nutritionally, rye is more similar to wheat when comparing all of the cereal grains.  Compared to oats, rye has less fiber, which allows it to meet nutrient requirements across all stages of production without adding too much fiber.

Nutrient Analysis comparing Corn, Oats, and Rye (as-fed basis)

Corn Oats Rye
Crude Protein (%) 8.3 11.5 11.8
Energy (ME, kcal/kg) 3,420 2,710 3,060
Lysine (%) 0.26 0.40 0.38
NDF (%) 9.6 27.0 12.3
ADF (%) 2.8 13.5 4.6
Calcium (%) 0.03 0.07 0.06
Phosphorus (%) 0.28 0.31 0.33

Source: Iowa State Extension, 2005

Historically, farmers in Europe have fed cereal rye to pigs, but for several years now, the inclusion of hybrid rye has been increasing in grow-finish, gestating and lactating sow rations. Research by SEGES, a Danish Pig Research Center found that pig producers recognized positive benefits when feeding hybrid rye. Producers noticed lower overall feed intake, less confrontational behavior, and fewer ulcerations in the hindgut. A feed trial with gestating sows showed that microbes in the stomach of pigs when digesting rye resulted in a slow rate of passage. The slower rate of passage gives the pigs a sense of feeling full, longer, causing the pigs to eat over a longer period; which reduces overall feed intake, less fighting at the feed bunk, and lower feed costs since pigs felt satiated longer. SEGES also found no significant performance differences between the control groups receiving a wheat-only based ration and the treatment groups fed rye-based diets.

In summary, what makes rye (both winter and hybrid) unique as a feed grain are its:

  • Lower fiber and higher energy content than oats
  • A slower rate of passage, so pigs stay fuller longer
  • Ability to reduced stress behaviors like nipping, bruising and mounting

Feeding Rye in Different Production Phases

We feed much less rye compared to pig producers in Europe, which originates from rye’s variable nutritional value due to the susceptibility of ergot. Hybrid rye’s resistance to ergot helps to address this issue, which is reflected in the inclusion rates below.

Rye is not recommended as a feed grain for starter pigs due to its lower palatability. In grow-finish pigs, it is recommended that rye grain replace no more than half of the corn in the diet. Lactating sow’s have a crucial need to meet their maximum feed intake and energy for milk production, therefore no more than 10% rye inclusion is recommended.

Grain Starters (less than 60 lbs.) Grow-Finish (below 125 lbs.) Grow-Finish (above 125 lbs.) Gestating Sows Lactating Sows
Winter Rye 0% <25% <35% 25% 10%
Hybrid Rye 0% <25% 50% 30% 30%

Compiled from the Tri-State Swine Nutrition GuideIowa State University ExtensionUniversity of Wisconsin-Platteville (Lammers, 2017), and SEGES

The majority of rye grain being produced in the Midwest is being grown and sold for distilling and milling purposes, with small amounts of it being marketed as a livestock feed ingredient. Because of limited supply, farmers are growing their own rye in order to include in pig rations.

Claus Nymand project manager for North America KWS, in a field of hybrid rye at Jude Becker’s farm in Dyersville, Iowa, in June 2018.

What are the seed costs for rye?

Typically, winter rye yields 30-60 bushels per acre, and hybrid rye varieties yield greater than 50% more compared to the open pollinated varieties. The University of Minnesota conducted field crop trials including two KWS hybrid rye varieties. A statewide, three-year average (2015-2017) showed the Bono variety produced about 187 bushels an acre and Brasetto produced 167 bushels an acre.

What is the cost of winter rye? This should be offered as a comparison to hybrid rye costs. Albert Lea Seed in Minnesota carries Bono and Brasetto, both $33 per 50-pound bag. Yankton Seed House in South Dakota carries these varieties for $30.50 per 50-pound bag. A recommended seeding rate is 75 pounds per acre, therefore costing between $46 and $50 per acre.

Although the current market for rye is scarce, there are elevators in Minnesota and Nebraska that will buy conventional and organic rye. Scoular Company out of Nebraska is currently buying organic rye at $6.00 per bushel. Several farmers are interested in growing hybrid rye for its yield and weed control benefits, but markets are scarce. Feeding rye to pigs provides a market solution – while diversifying our landscape. For more information on selling rye grain, check Albert Lea Seeds’, Who’s Buying Rye? Grain Market Buyers for Rye.

Sometime late November or early December, Albert Lea Seed will be hosting an open house with a session entirely on hybrid rye. The session will include preliminary research results that KWS and the University of Illinois are conducting to evaluate pig growth and reproductive performance on hybrid rye rations. Check Albert Lea Seed’s news page for open house date.

Currently, PFI on-farm cooperators are conducting hybrid rye variety trials and feeding trials on replacing corn with hybrid rye in grow-finish pig rations.

Stay tuned for our next blog in this series – Small Grains, Large Gains: Feeding Barley to Pigs.