That's your opinion, and it depends on whether you are referring to dairy production, weaning as separating like that in beef herds, or another reason that requires a calf to be separated from its dam or vice versa.
As far as dairy production is concerned, it may seem cruel to separate a calf from a cow that has just bonded with it, like after a day or two, but it's necessary because it's not a great idea nor is it productive to have a whole pile of calves loose in the barn or having to contend with being separated from their mothers for a short time twice a day when their mothers are being milked. The cows only bawl for their calves for a few days, then soon forget them and settle down to regular routine.
It is not cruel to separate a cow from it's calf during a time when calves MUST be weaned from their dams, especially when they don't need their mother's milk anymore. You may consider it cruel if the weaning process involves separating cow and calf into separate pastures where they can't hear, see or smell each other, but not if they are only separated by a fence or the Eezy-Wean nose ring is used for a short period before the calves are actually separated from their dams.
It is not cruel if you have to separate a cow from her calf if the cow cannot care for that calf for whatever reason: either she died from a complications, cannot get up after a difficult delivery, doesn't have enough milk to feed her calf and the calf needs to be orphaned onto another cow, the cow won't accept her calf despite everything a producer tries to do and has to bottle-feed or put the calf on a nurse cow, the calf has to be kept in a protected area because it is sick or injured or otherwise too weak to be able to keep up and suckle from its mother, etc. in these cases, mom and calf have to be separated, and, if and when necessary reunited only briefly to feed the calf its mother's milk.
A cow and calf should not be separated unless you are weaning them. Thus, if you are asking about weaning a cow from her calf and vice versa, you should keep them separate for at least 6 to 8 weeks, longer if the calf tries to go back to suckling his momma again when you put them back together.
The name of a baby cow is a Calf
The baby is called a calf and mother is a cow. Together they are called a cow-calf pair, or "mom and baby."
Cow. Calf came after.
A "calf".
A newborn calf, a baby calf or just a calf.
No. She will continuously produce colostrum for the calf even after the calf is born. But separate her from the rest of the herd so the calf does have a chance to suckle his momma and not get pushed away by a milk thief. Better yet, see if you can catch the milk thief suckling on that preg cow. If it's another calf, separate that calf with his momma in another pen. If it's another cow, put the cow through a catch chute, put a temporary spiked nose ring in her nose, and let her back with the herd. That nose ring should stop her from suckling milk from another cow.
The best thing you can do is to skin the dead calf of that beef cow's, and drape it over the orphan calf's body so that you trick the cow into thinking that that calf is hers. But this will only work if you have that cow's dead calf on hand and not if that cow doesn't have a calf or if you're wanting to put another calf on that cow. Other tricks include smearing cod liver oil or perfume or some other strong-smelling solution that's not poisonous to the cow nor calf over the cow's nose and all over the back and head of the calf, putting a dog in with the cow and the calf, etc.
A young cow, in the sense of it being female, is called a heifer. Heifers remain so until they have had a calf. However in the more general sense, a young "cow" is called a calf.
The offspring of a cow is referred to as a calf. A heifer calf is a female calf, a bull calf is an intact male calf, and a steer calf is a castrated male calf (castrated after birth).
Calf, Females are heifers and males are bullocks.
The name of a baby cow is a calf (plural: calves)