Source: Nature: "Holy Cow"
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Cows have adapted to an incredible range of environments as they have provided people with milk, meat, leather, and draft power. As a response to the many uses and habitats of cattle, a wide variety of breeds have been developed. Breeders of beef and dairy cattle carefully select cows from known breeds that will yield the most meat and milk. In this video from Nature, learn about the most desirable traits in both beef and dairy cows.
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Cattle originally evolved over millions of years through a process of natural selection-also known as “survival of the fittest”-which made them adaptable to a wide variety of environments, including most of those inhabited by another highly adaptable species: humans. Once humans discovered how to domesticate cattle about 4,000 years ago, they began to selectively, or “artificially,” breed them for specific desired traits like meat and milk production. This resulted in animals fit less for survival in the wild than the satisfaction of human needs, but in purely genetic terms, the arrangement has proven highly successful for cattle. Cattle now thrive throughout the world in over 800 different breeds, each more or less successfully adapted to their environment and the needs of their human caretakers.
Different cattle breeds reflect a combination of where they came from and what they are intended for. By exaggerating desirable characteristics through careful selection, man has created eight hundred different breeds with shapes and sizes never before seen in nature.
WEBSTER: In the gentle plains of Southern England, or on the great plains of the states, the beef cattle have been selected by man to produce beef, that’s to say they have short legs and vast amounts of meat all around them so they have been selected by the butcher in essence.
SHOW COMMENTATOR: The Winner of the perpetual trophy is the British Simmental champion Sterling Cracker Jack. The Presenter: Wonderful animal The Winner: Thank you very much indeed. Commentator: He is nearly 1600 kilos in weight.
Beef is only half the story and now it’s the turn of the diary cattle at the Malvern show. Exhibiting his classic black and white Holstein Friesians is dairyman David Kale with his daughter Emma. What qualities will the judges be looking for this time?
KALE: They've got great udders on them is what he's gonna be looking for, their teats are in the right place, their leg set is right, the openness of rib is right, the dairyness through the front end is right, the skin is even right. It's just what I think a modern day Holstein breeder would strive to try and breed ideally. You have to try to figure out what time the cow's gonna look her best. They were milked at 4 o' clock last night so we believe that they're capable of carrying about 17 or 18 hours of milk to look their real best. Cause at the end of the day if we don't get those udders blooming like they should and if we don't get that udder filled right to the top, she won't win her class.
WEBSTER: In a dairy cow such as this, this is the factory, this is the udder, where the milk is produced. In an Ayrshire cow, in a very natural grazing environment such as this will at peak give about 50 or 60 pints a day which is about 12,000 pints in a lactation. And it is secreted in cells that live in the top part of the udder, underneath that is a cistern, which is, as the name implies, it is just a tank that holds the milk. On the bottom of that we have the teat and the teat canal which remains closed for obvious reasons, until such time as either the calf comes to drink from its mother or she goes into the milking parlor. Then a hormone, Oxytocin, is released from the brain, is carried in the blood stream to the secretary cells of the udder and causes myoepithelial specialized cells that contract and squeeze the milk out of the secretary glands, into the cistern and out through the teat canal.
In the dairy breeds, milk production is what counts.
JUDGE: Worthy winners of the last class.
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