How farmers improve pig fattening with rye

Successful pig fattening and happy animals – Andreas von Felde believes they are not mutually exclusive goals. This Northern German farmer plants rye and uses it for feed. He needs less fertilizer, and a recent study backs him up.

Andreas von Felde knows precisely how to measure how happy his pigs are. The 52-year-old leans against the brick wall of his fodder silo, just around the corner from the sty. And listens. “We’re about 20 meters away from 500 porkers,” says the farmer from Harmelingen in the Lüneburg Heath, south of Hamburg. “And you can hear a pin drop.”

The silence in his herd isn’t just a momentary thing, as von Felde can attest. His bedroom is within earshot of his animals, and he has been able to sleep soundly for years. “But that wasn’t always the case,” he says. Pigs can easily become restless and then even begin biting each other’s tails off. Many fattening farms remove these curly tails to stop other pigs from biting them. Yet the main reason for that is not aggression, but hunger. And rye can satisfy that.

Natural satiation thanks to rye

The cereal contains complex carbohydrate compounds that are steadily and slowly broken down into glucose in the animal’s small intestine. The natural consequence is a lasting feeling of satiation. That and other effects of rye in pig fattening are described in a recent study conducted by the Foundation of the University of Veterinary Medicine in Hanover (TiHo) together with KWS and the Walsrode Livestock Marketing Cooperative. “There are indications that rye can have a favorable influence on animal behavior,” says Josef Kamphues, Professor at the Institute for Animal Nutrition at TiHo and the study’s lead author. The 18 farms that took part, including ten that rear boars, fattened more than 45,000 animals in the course of the study. They were fed with a mix in which rye accounted for a ratio of five percent in the pre-fattening period, 25 percent in the middle fattening stage, and finally 40 percent in the grow-finish stage.

That’s an unusually high figure – farmers often use far less rye in pig fattening. Yet the study’s results suggest that there are good reasons to reverse that trend. And not just because the pigs are more satiated. “We simply can’t continue using so much fertilizer as in past decades,” says Kamphues. “And rye helps agriculture take new approaches.”

  • There are some indications that rye can have a positive effect on animal behavior.

    Josef Kamphues, Veterinary College Hannover

Less nitrate with rye cultivation

Hybrid rye seed from KWS needs 100 liters less water per kilogram than wheat, for example, according to the seed breeder. And it requires half a kilogram less nitrogen per 100 kilograms of cereal. This ultimately means rye ensures there is less nitrate in the soil. And it makes it far easier for farmers to comply with the new German Fertilizer Ordinance that has been in force since 2017.

The veterinarian expert Kamphues also identified major differences compared to other types of feed for the pigs in the study: “Rye has a large amount of carbohydrates that are not digested in the small intestine. Put simply, they feed the microorganisms in the small intestine and the microflora there.” That produces butyric acid, which very likely has a positive influence on the behavior of animals when they are being fattened. Butyric acid is also very efficient at killing bacteria such as salmonella. And the problem of boar taint, which hangs like a sword of Damocles over the breeding of non-castrated male animals, might be significantly mitigated with a higher rye content in fodder. “We might well see a renaissance in rye,” says Kamphues. “That’s because the conditions for the plant and animal husbandry have changed – in favor of rye.”

Rye: resistant even in arid conditions

Strong plants swaying in the wind carry the secret to keeping pigs quiet and content during fattening. The extremely dry spring in 2018 apparently had only little effect on rye on the around 30 hectares of land not far from the farm. Andreas von Felde’s hybrid rye plants stand upright in the frugal, sandy heath that has additionally suffered from the lack of rain. “Resistance to drought is very advantageous for all of us here,” says von Felde. “In addition, the plants don’t snap in severe storms, and they deliver high yields on our difficult soils. And I hardly have any problem with diseases like rust or mildew.”

After all, modern breeding has virtually eliminated rye’s former weakness: susceptibility to ergot fungi. “I can largely prevent that by using the right variety and Pollen Plus technology. Many years of research by KWS have helped achieve advancements here. That process is just as complex as developing a new car.”

The long-established cereal is a key component of the philosophy for the von Felde family on its farm, namely a commitment to upholding tradition, but using state-of-the-art technology. The fact that von Felde himself works as a Product Manager at the seed producer gives added substance to his convictions.

Ryes: traditionally high-yielding

The farm has been family-owned for many generations – but even von Felde doesn’t know precisely how long. However, he can prove without a doubt that a lot of rye has been grown in his fields for decades. Just recently the farmer found a letter from his grandmother, who ran the farm in the 1940s. She remarked about the harvest: “We’ve again got good rye in the cellar.”

Von Felde, who holds a doctorate in animal breeding, inherited the farm in the year 2000. “Back then, animal welfare wasn’t as prominent a cause as it is today,” says the father of three. Yet that issue is very dear to von Felde’s heart: His pigs are bedded on straw, soccer balls dangle from the ceiling, and salt blocks and chew sticks offer them diversion. The animals have much more space and light in their open sty than elsewhere.

Animal welfare in pig fattening

He understands why some colleagues can’t or won’t adopt his principles in pig fattening – and urges them all the more to opt for his preferred cereal. After all, nothing has been the same since he significantly increased the rye content. “You can make a quick contribution to animal welfare by using rye as fodder,” he says. “By contrast, changing how you keep animals as a whole takes a lot longer.”

von Felde can hear that his pigs are doing well – and he feels that in the midst of his herd. The farmer regularly mingles with his animals to check that everything is as it should be: “You have to spend a lot of time with your animals. Then you notice a lot of things.” And von Felde has numbers to prove that rye does more than improve animal welfare: The lean meat proportion has soared from 58 to 62 percent and the gain in weight has increased from 810 to 900 grams a day.

“Stand firm, look far ahead and keep moving” – that was a slogan that used to adorn one of his farm buildings, says von Felde. The combination of tradition and modern methods, of animal welfare and efficient farming is now his trademark. This unpretentious farmer is even a little proud that TV teams visit his farm as a result: “I’m very grateful for that!”

Research on pig feed: greater animal welfare thanks to rye

Rye could radically redefine and improve pig feeding. A joint research project between the scientific and business communities aims to make a contribution to that. The German Ministry of Food and Agriculture is supporting the project* with funds from a government innovation program.

“Pig farmers are looking for new methods to feed their animals in a healthy and sustainable way. Rye and rapeseed could be part of the solution,” says Dr. Henning Ehlers, Chief Executive of the German Raiffeisen Federation (DRV).

Rye has specific advantages over other cereals: The plants need less water, less pesticide is required, and rye has the highest nitrogen and phosphorus use efficiency. “Rye therefore gains in importance when the aim is to use less fertilizer,” says Dr. Andreas von Felde, Head of International Product Management at KWS. It also copes with low-yielding sandy soils and at arid locations in Northern Europe.

Special constituents of the grain that are not recognized in traditional feed analysis are responsible for the positive effects of rye in pig feeding. “They are certain carbohydrates that are not starch in the actual sense. These substances – such as fructans – are termed non-starch polysaccharides and are broken down only by the gut flora and finally used by the organism. That means rye – and not barley or oats – is the most fiber-rich cereal there is,” states Professor Josef Kamphues, Director of the Institute for Animal Nutrition at the University of Veterinary Medicine in Hanover.

Non-starch polysaccharides are a particularly suitable foundation for intestinal flora to produce butyric acid. The project’s initiators hope that the butyric acid formed in the intestine will help promote the health of pigs in various ways. The scientists are investigating the hypothesis that increased butyric acid levels help protect against salmonella and reduce boar taint.

The parties involved in the project, which will run until 2021, are responsible for specific tasks:

  • KWS – together with the Walsrode Livestock Marketing Cooperative and the feed compounder Raiffeisen Mittelweser – is conducting practical trials with defined rye qualities.
  • The right feed mix is being developed at the Institute for Animal Nutrition at the University of Veterinary Medicine in Hanover.
  • Animal nutrition experts at the Free University of Berlin are examining, among other things, the effects of compound feed with a high rye content on the intestinal mucosa and inflammations.
  • Animal nutrition experts from the Rheinische Friedrich Wilhelm University in Bonn are looking at the special carbohydrates in detail. For example, they are investigating which constituents of rye actually reach the small intestine and which produce a feeling of satiation among pregnant sows so that they are calmed down.

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