<P> To maintain lactation , a dairy cow must be bred and produce calves . Depending on market conditions , the cow may be bred with a `` dairy bull '' or a `` beef bull . '' Female calves ( heifers ) with dairy breeding may be kept as replacement cows for the dairy herd . If a replacement cow turns out to be a substandard producer of milk , she then goes to market and can be slaughtered for beef . Male calves can either be used later as a breeding bull or sold and used for veal or beef . Dairy farmers usually begin breeding or artificially inseminating heifers around 13 months of age . A cow 's gestation period is approximately nine months . Newborn calves are removed from their mothers quickly , usually within three days , as the mother / calf bond intensifies over time and delayed separation can cause extreme stress on both cow and calf . </P>
<P> To maintain lactation , a dairy cow must be bred and produce calves . Depending on market conditions , the cow may be bred with a `` dairy bull '' or a `` beef bull . '' Female calves ( heifers ) with dairy breeding may be kept as replacement cows for the dairy herd . If a replacement cow turns out to be a substandard producer of milk , she then goes to market and can be slaughtered for beef . Male calves can either be used later as a breeding bull or sold and used for veal or beef . Dairy farmers usually begin breeding or artificially inseminating heifers around 13 months of age . A cow 's gestation period is approximately nine months . Newborn calves are removed from their mothers quickly , usually within three days , as the mother / calf bond intensifies over time and delayed separation can cause extreme stress on both cow and calf . </P>
how do cow produce milk all the time
how do cow produce milk all the time
must be bred and produce calves
must be bred and produce calves