Cattle are used for many purposes around the world. To meet the many different needs of people, more than 200 breeds have been developed. Some of the breeds have been created for meat production, while others have been selected for high milk yields. Cattle come in many colors, from solid white, black, yellow, red, or gray to spots, brindle, and roan mixtures of all colors. Coat color does not affect the quality of the beef or milk the animal produces. Contrary to what some people believe, all cows produce white, unflavored milk, even black, red and yellow ones! Colors and flavorings are added by humans during processing.
Cattle are mammals just as humans are. So, both cattle and humans are warm-blooded, have hair, give birth to live young, and produce milk to feed their young. But cattle and people differ greatly in many other ways...not the least of which is their external appearance!
For example, genetically, cattle have 30 pairs of chromosomes, while humans have only 23 pairs. Why is the chromosome number important? Because it is by matching the genes on the chromosomes of selected males and females that producers generate superior offspring.
One of the most important tools cattle farmers have to improve their herds is artificial insemination, called AI. AI lets producers mate their cows to extremely high quality bulls most farmers could never afford to buy themselves. The farmer purchases frozen semen collected from these "super" bulls and then breeds the cows with it. Many producers still buy locally-produced bulls and turn them into the pasture with the cows for natural mating, but more and more producers choose to have the best bulls in the world delivered right to their farms to breed their females using AI.
Another major difference between humans and cattle is our digestive systems. After all, cattle can live on grass and humans cannot! Cattle are ruminants which means they have a single stomach with four compartments, not just one like a human. The 4 parts of the stomach are the reticulum, rumen, omasum, and abomasum. The reticulum and rumen are a huge (40 gallon!) fermentation vat. The reticulorumen receives the grass, hay, and other feeds the animal consumes and the billions of microorganisms that live in there ferment and digest the cows all-plant diet. Only microorganisms have the enzymes to digest the cellulose in plant cell walls.
As you saw in the field trip, to study how the microorganisms in the rumen work, scientists can put a fistula (a hole into a hollow organ) in the ruminants side. A cannula (the plastic ring and stopper) is placed inside the fistula to maintain normal conditions inside the reticulorumen. With the cannula in place, the scientist can reach inside the reticulorumen to take samples or add treatments. The goal of the scientist that works with cannulated animals is to improve productivity by turning more of the feed the animal eats into meat and milk.
There are actually two different types of cattle to meet the human demand for meat and milk. Beef cattle are used to produce meat and dairy cattle are used for milk production. Both types actually produce both meat and milk, but dairy are much better at producing milk than meat and the opposite is true for beef cattle. All cattle supply the human demand for leather and provide us with many by-products for use in a wide variety of items, including pharmaceuticals, processed foods and fabrics, screws, asphalt, building materials, make-up, furniture, and even explosives.
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