When fostering or “grafting” an orphan calf or twin onto a cow that lost her own calf at birth, some producers skin the dead calf and tie the hide onto the substitute calf. If the cow had a chance to lick and smell her dead calf before it was taken away, tieing its hide over the substitute calf can often trick her. Cows recognize their calves by smell; the hide of her own calf may make her think the newcomer is hers.
Other producers put various products on a calf to encourage the cow to lick it.
“There are many tricks, like using molasses or a product that smells like licorice,” says Andy Acton, a veterinarian with Deep South Animal Clinic in Ogema, Sask. “Some guys swear by certain products, and these might work in some cases.”
“One thing that works is a tip I learned from Dr. Joe Stookey at the Western College of Veterinary Medicine,” Acton says. “Stookey suggests putting birth fluid over the calf. The amniotic fluid that surrounds the fetus in the uterus is very salty and tangy, and cows are usually interested in smelling and licking it off their newborn calf, which starts them licking and cleaning up the calf. If the cow/heifer has just calved, smear birth fluids onto the substitute before you bring him to her.”
Producers probably aren’t present for every birth, but if the circumstances work out they can collect the amniotic fluid when possible and then freeze it for later use. “If you are present during a normal birth or need to help a cow or heifer calve, have a clean towel handy, and when there’s a lot of birth fluid, soak the towel in that fluid,” Acton says. “ Put the towel in something waterproof like a plastic bag, and freeze it.”
If you are later getting a cow to accept a substitute calf, thaw out that towel and rub the fluid onto the calf. This is useful if you need to foster a calf that might be several days old onto a heifer or cow that loses her own calf at birth. “The birth fluid doesn’t have to be hers,” Acton says. “She doesn’t know the smell of her own calf at first until she’s bonded with it and knows its smell.”
If you use this fluid/towel trick, remove the dead newborn before the cow or heifer has a chance to smell and lick it, and she’s more apt to think the substitute is hers because it smells and tastes like birth fluid.
“As long as everything is healthy and clean when you collect fluid from a calving cow or heifer, just soak a towel or two and have them frozen and ready to grab out of the freezer,” Acton says. “Then you can simply thaw one out and use it to smear up another calf if you need to foster one.”
If the calf is too lively
If the calf being grafted is particularly lively, this may startle or confuse the prospective mother. The bouncing baby might scare a heifer or make a cow suspicious that this lively youngster is not her newborn. Acton suggests tying the calf to the side of the stall/pen so it can’t run around, or laying it on the ground and tying its legs together so it can’t get up. This gives the cow/heifer a chance to sniff and start to lick it without becoming alarmed or suspicious by overactivity. Once she starts licking the calf and mooing and mothering it, the calf can be untied.
Also as part of this grafting process, it’s best to bring the calf to the mother when the calf is hungry. The calf will seek out the udder as soon as it is brought to the cow. The sooner it nurses, the better. Nursing triggers release of oxytocin in the cow, which stimulates motherly behavioUr. If she does not let the calf nurse right away, you might have to put her in a head catch and let the calf nurse while she’s restrained. Usually once the calf nurses, and if the calf smells and tastes like birth fluid, she will accept him as her own.