Using rye in swine feed

Friday, November 26, 2021

New hybrid rye lowers risk of ergot in feed rations.

By Michelle Jones

Rye isn't used a lot in pig rations, mostly because there isn't a lot of it grown in Canada due to its susceptibility to ergot. While other grains such as wheat and barley are also prone to the disease, ergot seems to affect rye more often, so farmers have been hesitant to grow it or use it as feed because of the risk involved. However, research was still conducted on the nutritional value of rye, even if it wasn't widely used as feed.

"If you look back in the literature, there was a lot of research done with looking at rye in pig feed, and they found it could be used quite well," Dr. Denise Beaulieu tells Better Pork.

Beaulieu is an assistant professor, monogastric nutrition, at the University of Saskatchewan.

"If you look at rye and you measure the nutrient content by doing some simple chemistry analyses, you realize it's a lot like wheat. So, you can feed it like wheat," she says.

But, because of the risk of ergot, rye isn't typically used in feed. However, that could change.

Less susceptible to ergot

There is now a hybrid rye that was developed in Europe making its way into Canada, and it's shown to be less susceptible to ergot, making it safer to include in swine feed.

"The hybrid rye that was developed in Europe apparently yields very well and is less susceptible to ergot. So, now producers would have confidence that it would not be contaminated with ergot and can safely feed it to their pigs," says Beaulieu.

Dr. Laura Eastwood agrees. She is a swine specialist with the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA).

"Out of Europe, we've seen this new hybrid rye being grown on the Prairies and some here in Ontario. It's less susceptible to ergot contamination. I don't know all the details of how, but it has something to do with the amount of pollen that forms. They still can be contaminated, but at lower levels," she tells Better Pork.

"We may see more inclusion into pig rations if growing it takes off in Canada, depending how much of it goes into the distillery market," says Eastwood.

She also says that from a cropping perspective, this new hybrid has higher yields than wheat, barley and regular rye, so growing it in Canada has benefits.

Producers across Canada are now looking at adding it to their crop rotations to sell to distilleries. This means that any rye that doesn't grade high enough for the distillery market can then be sold as feed, according to Beaulieu.

Rye in feed rations

Beaulieu is currently doing this research on rye in pig diets so pork producers will be comfortable using it in their feed rations. She recommends that producers still have the rye tested for ergot before purchasing, and if ergot isn't an issue, they can feel confident in using it as nutritious swine feed.

When adding rye, she suggests that you can include it by replacing wheat or other cereal grains.

"In an older animal, 50- 60 per cent of their diet can be rye and the pigs will grow fine. Most producers wouldn't do that, but that's only because of supply and cost. Because the hybrid rye is relatively new to Canada, there isn't much supply yet," she says.

In Ontario, there has also been research done on replacing a portion of the corn with rye in diets and doing so successfully, according to Eastwood.

"As far as performance with the hybrid rye, by substituting grains or corn, as long as the rations are balanced, we aren't seeing any negative impact on the growth of the pigs as long as the energy level in the feed is maintained. And maintaining the energy level is very important.

"If the energy level isn't met when including rye, the fibre in the rye essentially creates a viscous material in the intestinal tract. So, in a low-energy diet, they're just not getting as many nutrients as you may think they're getting, and it can impact their growth performance," she says.

Feeding rye to piglets

Eastwood says it's safe to feed rye to piglets in small amounts, as with any cereal grain.

"We've had several studies and producers feeding it to piglets with success, but you want to keep inclusion levels low right after they're weaned, just to get their digestive system up and running with those types of products," she says. "They're going from milk to a solid food, and that's pretty abrupt, so there's no problem with including it; it just needs to be included at a low level for the first while and as they get bigger, you can ramp that up."

Beaulieu agrees.

"You would include it in lower amounts. Producers want to be very careful with their newly weaned piglets, and just until there is more information out there, they may not include a lot. But recent studies show it's acceptable for newly weaned piglets to have rye included in a high-protein diet," she says.

Feeding rye to lactating or gestating sows

Eastwood does not recommend feeding rye to lactating sows because of the ergot risk.

"Even if you test and it comes back negative, it doesn't take much, so even if you have one contaminated grain in a one-tonne barrel, you might still have a problem. So, it's not worth that risk with your lactating sows," she says.

Rye is still perfectly safe to feed to the rest of the pigs, though, including pregnant sows. In fact, the fibre source seems to be good for them.

"We like to have diets that have a good fibre source for gestating sows to make them feel as full as we can while they're being restricted-fed, and that viscus fibre is known to have a better satiation effect than some of the others," says Eastwood.

Beaulieu is currently looking at the fibre in rye and its effect on satiety and making the pig feel fuller, especially in gestating sows.

"Sometimes, a sow that's pregnant, we limit-feed her so she doesn't get too fat. Too much weight gain can cause problems at farrowing when she has her babies.

"So, at the end of the day, she feels hungry. We're looking at ways to make her feel fuller, but that's an area we're still looking at," she says.

This area would be the fibre and the specific chemical constituents of the fibre itself. Beaulieu thinks it affects the gut microbes, or that feedback signals to the brain might be different. While they don't have any scientific evidence as of yet, she says it appears the grain chemistry has a satiating effect on her pigs, helping them feel fuller quicker. This is something they are going to begin testing.

"There hasn't been a lot of work done on that because we're just starting to look at feed-rye now, and we're looking at these different aspects of it. But, that would certainly be a positive, where it could have these non-nutritional benefits that it creates a satiating effect. We've got some evidence for it, but not from studies that were really done, but we have noticed some very interesting characteristics (by feeding pigs rye)." BP