Occasionally a cow loses a calf at birth or a calf loses its mother, and you need to “graft” the orphan or a substitute calf onto another cow. Or, a cow might have twins and can’t raise both and you want to put the extra calf onto a cow that lost her own. Sometimes it’s prudent to graft an old cow’s calf (so the old cow can be fattened and sold) and put her calf onto a younger cow that lost a calf.
It can be sometimes challenging to convince a cow to adopt the substitute calf. There are many tricks a person can try, according to Dr. Mark Hilton, beef production medicine, Purdue University. He says the most reliable way is to skin the dead calf and put the hide on the substitute.
“You don’t need the entire hide,” says Hilton. “About half to three-quarters of it will do. The important thing is to leave the tail on, since the cow will spend a lot of time licking that end of the calf.”
The cow knows the smell of her own calf (even if it was dead at birth — if you gave her a chance to first smell and lick the body). This “smell bonding” can trick the cow into thinking the substitute is her calf.
Grafting works best when a cow loses her calf while it is very young. Her mothering instinct, due to hormonal changes during the birth process, is strongest soon after she calves, and she can be more readily convinced to accept another young calf in place of her own. If her own calf dies after it is a few days or weeks old, it is harder to trick her into taking a different calf.
“Make holes in the hide so you can attach strings or baling twine,” says Hilton. “I generally put holes in front and back of the front legs and in front of the hind legs, to tie the hide onto the calf. Leave the hide on for three to four days; generally that’s enough time to convince the cow it’s her calf — and the hide starts stinking by then and you’ll want to take it off.”
Bring the “new” calf to the cow when the calf is hungry and eager to nurse. The sooner the calf nurses, the better, if she lost her own calf at birth. Nursing triggers release of oxytocin in the cow, which stimulates motherly behaviour. You want the cow to accept the calf before she becomes suspicious. Once the substitute calf has nursed a few times and the cow is accepting him, it is usually safe to take off the old skin.
From the Canadian Cattlemen website: Late weaning
He says using hobbles on the cow’s hind legs to keep her from kicking the calf has proved to be the best method to get the cow to accept the graft calf when no hide is available. “After about a week the cow usually gives up and lets the calf nurse,” he says.
Hilton says always introduce the calf when it is hungry. Put the cow in a chute if the cow does not let the calf nurse right away and let the calf nurse while the cow is restrained.
“You can also pen the calf separately and supervise the nursing two or three times a day,” he says. “A short gate or panel separating them is best, so the cow can reach over and nuzzle the calf if she wants.”