Toxins are a concern, but they generally do no harm under managed grazing and when a variety of forages is available
FORT MACLEOD, Alta. — Cattle can learn to eat new forages and teach others to follow suit, said grazing specialist Kathy Voth.
She runs Livestock for Landscapes out of Arizona and works with ranchers to train their cattle to get rid of a variety of troublesome plants like leafy spurge, knapweed, Canada thistle, pigweed and a long menu of other weeds.
Many of these plants provide good forage with high levels of protein, she said at a recent session sponsored by the Foothills Forage Association in Fort Macleod, Alta.
“A cow chooses what to eat based on what her body needs,” she said.
“A cow eats what her mom eats.”
Concern over toxins in some of these plants is real, but they generally do no harm when grazing is managed carefully and cattle have a variety of other forages in the pasture.
When a toxin in a food disagrees with an animal it eats less. Animals do not avoid food because it tastes bad, but will avoid it if it makes them feel sick, she said.
“As long as they can mix leafy spurge with a variety of other forages, they will do just fine. It is very high in protein and is very nutritious,” she said.
Her program starts with a few healthy animals from a herd.
“They have to be healthy animals. They can’t be starving. Starving animals can’t deal with toxins, can’t deal with new things quite as well,” she said.
She starts the program by arriving in her truck and honking the horn so the animals will associate her with food. She offers different treats in a feed tub that have a variety of textures, flavours, shapes and smells. Range cubes, wheat bran, alfalfa pellets, corn or barley may be new to the animals but they know it is good to eat. Weeds are slowly added to the mix.
“What the training does is shows them something new could be good to eat,” she said.
Within seven or eight days they can be given straight weeds and they will try them. Once they are on pasture they will try the weeds and others follow.
They do not have to learn to eat every weed. They will also try prickly plants like thistle.
Grazing management is important.
“If you would like more grass, then you have to focus your animals on weedy pastures at a time when weeds are going to be most susceptible,” she said.
Plants are most vulnerable just before blooming. The plant may reflower but the seed is less viable. The cattle are less likely to try the weeds when seeds are setting.