Cow

A cow is a calved female of cattle, that is, a domestic bull. Before becoming a cow, the female bull is a heifer (until the first fertilization), after fertilization until the first birth, she is called a heifer.

Cows are used to obtain offspring, as well as dairy and meat products.

Cows are also called females of some other artiodactyls, for example, bison.

In the inguinal region there is an udder - a mammary gland, which is divided by a median septum, which performs a supporting function, into right and left halves. Each half consists of two quarters — anterior and posterior, or femoral. Each quarter has a nipple from 5 to 10 cm long and 2-3 cm in diameter, cisterns and a glandular part. Milk is produced in the secretory epithelium of the smallest cavities - the alveoli located around the milk ducts, the latter open into the milk tanks. Milk retention in the udder occurs due to the capillary effect, as well as the sphincter muscles located around the large milk ducts. To produce 1 liter of milk, a cow needs to pass 500 liters of blood through the udder, so it is abundantly provided with blood. In dairy cows, the udder has a cup-shaped shape and protrudes forward, has equal symmetrically arranged lobes. Long, convoluted veins are clearly visible.

Heifers of most breeds grow up to 5-7 years, in late-maturing ones up to 6-7 years.

At the age of 7-10 months, heifers become sexually mature. The first insemination, natural (mating) or artificial, is carried out at the age of 16-18 months.

The duration of pregnancy, which in cows is called pregnancy, is 250-310 days. Before calving, during the so-called dry period of 45-60 days, cows are not milked ("run"). The duration of the lactation period (milk excretion) is 280-320 days. The largest amount of cow's milk is given during the fifth-sixth lactation. The life expectancy is about 20 years (in rare cases 35), while the period of economic use is up to 12-13 years, during this time 9-12 lactation is used. 5-10 years are used as breeding animals.