The average dog pregnancy lasts 63 days, which equals 9 weeks.
Wait for her to be in heat before you get her bred by AI. Or, the easier method is just to leave her with a bull for a couple of months.
Heifers getting serviced by a bull or through artificial insemination to get pregnant and give birth after 9 months of gestation.
Copulation or conception. This occurs when the bull ejaculates sperm into the cow, which encourages a series of events that allows a cow to become pregnant and give birth to a calf over 9 months later.
Elephants have one of the longest gestation period among mammals. They are pregnant for a period of around 22 months. After the 22 month gestation, they giver birth to a calf that is approximately 250 pounds heavy and stands at around 2.5 feet tall
Sometimes, if her pheromones are producing more estrogen than usual. But most pregnant cows won't have anything to do with a bull.
Yes. That's the only way you will get a calf. Breeding a cow to another male animal (except a bull bison or carabao) will not get her pregnant.
You can't, unless you make the bull a steer.
A bull calf is male with male reproductive organs, which means he cannot get pregnant. Only females (heifers, possibly heifer calves and cows) can get pregnant. Thus, your question has no merit whatsoever.
At about 10 months old.
3 months
bull shark
Around 24 to 36 months.