A cow is a female bovine that has already had a couple calves. Therefore, I believe you are asking about how long a cow is ready to breed after giving birth, which would be, on average, 45 to 60 days, depending on her condition and nutrition. Thinner cows tend to take longer to get back into cycling and may not be able to breed until 60 to 90 days after parturition.
If you are referring to the colloquial version of a cow and this "cow" is in fact a calf, you will have to wait until at least a year (preferably at least 15 months) until this calf, turned heifer, is ready to breed.
It could mean that a cow is ready to give birth.
It takes two to five seconds for a bull to copulate with a cow.
When she goes into heat. A cow can only be bred if she's in heat. If not, then it's not worth the effort to breed her. See the related question below.
Immediately
It depends on how much this "average" cow weighs and whether you're referring to the amount of ready-to-eat meat on a cow or the hot-carcass weight of that "average" cow. It also depends on whether you're referring to a "cow" or a cow, its type and breed.
Breed her and see if she settles long enough to birth a calf.
It could mean that a cow is ready to give birth.
A Long horn cow is a cow with long horns, however Longhorns are a breed, typically referring to the Texas Longhorns.
Flehmen response.
It takes two to five seconds for a bull to copulate with a cow.
It should only be a matter of a couple hours.
One day.
When she goes into heat. A cow can only be bred if she's in heat. If not, then it's not worth the effort to breed her. See the related question below.
Normally, no. The only time a cow would have a temperature if she was fighting an infection or illness of some sort.
Immediately
It depends on how much this "average" cow weighs and whether you're referring to the amount of ready-to-eat meat on a cow or the hot-carcass weight of that "average" cow. It also depends on whether you're referring to a "cow" or a cow, its type and breed.
From nose to rump, between 5 and 8 feet in length, depending on the breed and size of the cow in question.