Milk Production: Due to Pregnancy

Cows are mammals who, like us, produce milk in their mammary glands to feed their young. They therefore must give birth to a calf in order to produce milk and must be re-impregnated every year to keep that milk supply going. Most dairy heifers are impregnated for the first time when they are between 15 and 18 months old, giving birth to their first calf nine months later. Most dairy herds in the UK are now artificially inseminated (AI) as this is much cheaper than keeping a bull and allows farmers to select the sire from a variety of breeds. AI is now in fact a very lucrative business, with the dairy farming sector split between farms which produce milk and farms which produce semen. The use of more invasive practices such as multiple ovulation therapy and embryo transfer is increasing steadily in the UK and the rest of Europe.