A cow with prominent and less muscle than is typical of beef breeds Dairy cattle also called dairy cows are cows bred for the ability to produce large quantities of , from which are made. Dairy cows generally are of the. Historically, there was little distinction between dairy cattle and , with the same stock often being used for both meat and milk production. Today, the bovine industry is more specialized and most dairy cattle have been bred to produce large volumes of milk. Cows on a dairy farm in Maryland, U. Dairy cows may be found either in or where dairy farmers own, manage, care for, and collect from them, or on commercial farms. Herd sizes vary around the world depending on landholding culture and social structure. The United States has 9 million cows in 75,000 dairy herds, with an average herd size of 120 cows. The number of small herds is falling rapidly with the 3,100 herds with over 500 cows producing 51% of U. The United Kingdom dairy herd overall has nearly 1. In New Zealand, the average herd has more than 375 cows, while in Australia, there are approximately 220 cows in the average herd. The United States dairy herd produced 84. The top breed of dairy cow within Canada's national herd category is Holstein, taking up 93% of the dairy cow population, have an annual production rate of 10,257 kilograms 22,613 pounds of milk per cow that contains 3. Dairy farming, like many other livestock raring, can be split into intensive and extensive management systems. Intensive systems focus towards maximum production per cow in the herd. This involve formulating their diet to provide ideal nutrition and housing the cows in a confinement system such as free stall or tie stall. These cows are housed indoors throughout their lactation and may be put to pasture during their 60-day dry period before ideally calving again. Free stall style barns involve cattle loosely housed where they can have free access to feed, water, and stalls but are moved to another part of the barn to be milked multiple times a day. In a tie stall system, the milking units are brought to the cows during each milking. These cattle are tethered within their stalls with free access to water and feed are provided. In extensive systems, cattle are mainly outside on pasture for most of their lives. These cattle are generally lower in milk production and are herded multiple times daily to be milked. The systems used greatly depends on the climate and available land of the region of which the farm is situated. To maintain , a dairy cow must be bred and produce calves. 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 or. Dairy farmers usually begin breeding or artificially inseminating heifers around 13 months of age. A cow's gestation period is approximately nine months. Domestic cows can live to 20 years; however, those raised for dairy rarely live that long, as the average cow is removed from the dairy herd around age four and marketed for beef. In 2014, approximately 9. These animals may be sold du
