Only one.
A cow has an average of 1 calf per year after 2 years of age. So, depending on how long she lives for, she may only have one calf then be sent to slaughter, or she may even have as many as 18 or 20 during her lifetime, if she's a good producing cow.
A cow can deliver one calf at a time.
That depends on the type of cow. A dairy cow is able to feed four at one time, whereas a beef cow will be only able to feed one calf at a time--two if she's a really good producer or has a significant amount of dairy influence in her.
Most of the time only one. It is very rare for a cow to have two, even so one or both usually dies do to complications. It is even more rare for a cow to have three.
A cow will only calve once a year, and only give birth to one calf (twins 1:1000 births) at a time.
Always one. I've never heard of two calves being born at the same time; if there were twins, it's always one after the other, as the cow's pelvis is only wide enough to allow one calf through at a time.
One in three pregnancies is a miscarriage.
Just one.
one
There are many jokes about a cow and a farmer. One joke is about the cow who kicked the old farmer.
An average cow will usually have one calf per pregnancy but occasionally she can have twins, and triplets very rarely.
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