Cattle are cattle of the family Bovidae.

Cows are strong animals, and both sexes have horns. There are 5 genera. Most of them are giant herbivores. These include African buffalo and American bison, yellow cattle, buffalo, yak and so on, which are very important to human beings. They are strong and not good at running. The neck, shoulders or back often have protrusions supported by the spinal dorsal spine, which are muscular; There are four toes on the foot, but the lateral toe is worse than the deer.

Cows have four stomachs, namely rumen, reticulum, double-valve stomach (commonly known as tripe) and abomasum. These four stomachs actually overlap each other, but are not connected in sequence. Only the last abomasum secretes gastric acid to digest food, while the first three stomachs are rich in bacteria and protozoa. There are a large number of microorganisms in rumen, and the fermentation process will occur after food is swallowed, so that indigestible organic substances such as cellulose are decomposed and absorbed by rumen. The gas produced by fermentation is discharged by burping. Some food in the rumen will re-enter the mouth through the contraction of the rumen, and will be swallowed again after further chewing. After that, the food will creep between the reticulum and rumen, thus mixing and grinding, and a small amount of food will return to the mouth again after this process. Double-flap stomach will absorb the water in pulp and avoid diluting gastric acid. Eventually, protein and fat in food will be digested by enzymes in abomasum. The rumen of adult cattle accounts for 80% of the whole stomach volume, but the abomasum of newborn calves is the largest, and their ability to digest fiber feed such as grass is weak. The digestive process is similar to that of animals with only one stomach, and the rumen volume will increase with age. The small intestine of cattle is about 40 meters long, and the large intestine 10 is more than 0 meters. It takes about 7 or 8 days for food to be digested and excreted.

The front teeth and canine teeth of cattle degenerated, but the lower front teeth remained and the lower canine teeth were cut. Three pairs of front teeth are inclined forward and shovel-shaped. Because they feed on hard plants, premolars and molars are high crowns, and the enamel is wrinkled. After the crown is worn, complex tooth patterns are formed on the surface, which is suitable for grazing. Four rooms in the stomach, perfect ruminant function; Adult males and females have cave horns, and the cross section of the horns is circular or triangular. It is a symmetrical bone branch originating from the frontal bone process, which is not bifurcated and hollow inside. It is covered by a separable horny sheath (horny sheath) at the center of the bone horn and expands with the growth of the bone center. There are no nerves and blood vessels on the angle, and the hole angle can not grow after resection; Generally, when it grows to a certain extent, it stops growing and the horn sheath is not replaced.

Bison are very social animals. They gather in large groups, and some groups can even be concentrated to hundreds of people. These herds usually consist of females and calves, although there are occasional bachelors in some ethnic groups. Usually, older and experienced bulls tend to act alone and only appear together during the breeding season. Men have a strict hierarchy in body shape.

Cattle are obligate herbivores, tend to live in groups and forage in open grassland habitats. As an all-herbivore, large cattle consume high-fiber vegetation and contain more cellulose and lignin than forest animals. However, all cattle animals are dedicated herbivores, so they support microbial communities (bacteria, protozoa and fungi) in rumen, which helps to decompose cellulose and lignin and convert high-fiber feed into abundant energy.