Tansy control | Goats devour invasive weeds to allow grass to grow in cattle pastures
Lynn Colyn spent more than a week last month living in a pasture alongside her goat herd — and she says she’d do it again.
For the commercial goat producer, it was an extreme form of intensive management she regularly employs on her ranch near Naicam, Sask.
Colyn manages 200 meat and dairy animals, regularly rounding up and moving goats, building temporary fencing and employing both a guardian dog and a watchful eye.
So it wasn’t a stretch for Colyn to temporarily relocate 120 of her meat goats to a bushy pasture near Melfort, Sask., owned by the Western Beef Development Centre.
“Overall it was a good experience,” she said of her participation in a demonstration project that used goats to mow problematic paddocks infested with a noxious weed.
The goats arrived July 9 and were used to clear areas inhospitable to cattle because of excessive growth of common tansy.
The invasive plant is unpalatable to cattle and can be toxic because of the chemical thujone.
The extreme infestation and difficult-to-access area made spraying weeds problematic, said Nadia Mori, a regional forage specialist with Sask-atchewan Agriculture who oversaw the project.
“Where the tansy actually is, there is very little actual forage left because it’s so thick,” said Mori.
The goal is to provide a model that’s a win for both cattle and goat producers, offering sustainable, cheaper weed control and improved stocking rates for one and forage for the other.
The project, which is funded through the Agriculture Demonstration of Practices and Technologies initiative, builds off a previous multi-species grazing demonstration at the Wolverine community pasture in 2012.
That project saw goats provide 80 to 100 percent defoliation on shrubs in targeted areas.
Colyn said the goats, which regularly graze bushes and ditches, were familiar with tansy but had never grazed so much of the plant.
Colyn shepherded the animals 1.5 kilometres every day to the pasture, where they fed on the tansy for up to nine hours before being corralled and walked back to camp for nighttime protection from predators. The animals foraged on the way to and from and had access to hay and water at night.
“It wasn’t like they were eating solely tansy,” said Colyn, who has raised goats since 2007.
“But when they got into a paddock, they went after the tansy tops first and then they’d go after other stuff and then they’d come back and finish off the tansy.”
The goats proved to be an effective control.
Mori said they cleaned up eight 90 by 100 foot paddocks in eight days, although she added that the area would have to be grazed three or for years in a row to get a kill.
“I was almost concerned that they were eating too much of it because it does have some chemical compounds in there that we were concerned about for neurotoxicity.”
Colyn said the animals showed no negative effects from the tansy. A handful of animals were removed during the demonstration, but she suspects that was for other reasons.
Mori and Colyn were surprised by how well the animals took to the pastures. Despite their reputation, goats can be picky eaters, said Colyn.
“It didn’t set the herd back.”
Mori said an analysis of common tansy found it is a surprisingly high quality forage, albeit one challenged by thujone. The analysis found a crude protein content of 24 percent.
“What we’re missing for a lot of the plants is the chemical assay to know what’s in there,” she said.
“Nobody is really looking at these plants because they’re not a feed source, usually.”
Colyn suspects the tansy would affect the quality of milk produced from her dairy herd. She has no concerns about her meat animals, although she is taking precautions and will be holding onto them into the fall.
“They’ll be on hay and regular grasses and everything until they get shipped, so I don’t have any concerns,” she said. “I think that flavour will be gone by the time I ship them.”
Obstacles to continuing this type of collaboration include the small size of the Canadian goat industry and difficulties placing a value on the service. However, Mori believes there is room for producers to work together or use multi-species grazing practices.
“I know we’re dealing with a lot of perception issues. I’ve certainly talked to many cattle producers who feel that working with goats is below their level. I just think it’s a very big untapped potential. We do import so much goat meat. We have nowhere nearly enough to satisfy our Canadian market,” said Mori.
“There’s a lot of hurdles, yes, I see that, but there’s also a lot of potential.”
Colyn said she’s happy to educate others about the animals.
“Anytime I can do that, I find it a benefit. It’s a benefit to the species, it’s a benefit to me in the operation.”