How to identify the age of dairy cows

The age of dairy cows is an important index to evaluate the economic value and breeding value of dairy cows, and it is also an important basis for feeding management and breeding. When breeders buy dairy cows from other places, in the absence of detailed cow files, the age of dairy cows can be estimated according to their appearance, angular wheels and teeth, among which the identification of teeth is more accurate.

Appearance identification

Young cattle generally have a glossy coat, moderate roughness, soft and elastic skin, full eye pelvis, bright eyes and lively manner, while old cattle have dry skin, rough coat, sunken eye pelvis, dull eyes, wrinkles on the rims and slow movement. According to these characteristics, we can roughly distinguish between old and young dairy cows, but still can not accurately judge the age of cattle.

Angle wheel identification

Due to the influence of nutrition level all the year round, the length and thickness of horns change in the degree of growth, thus forming a grain of length and thickness. In the area with four distinct seasons, when cattle graze naturally or rely on natural forage, the grass season is nutritious and the horn grows faster, while in the dry grass season, the nutrition is insufficient and the horn growth is slow. Therefore, a corner wheel is formed every year. Therefore, according to the number of angular rings, the age of the cattle can be estimated, that is, the number of angular wheels plus the growth years of the untextured tip of the horn (about 2 years), which is equal to the actual age of the cow.

Dental identification

It is usually based on the occurrence, replacement and wear of incisors. There are 32 teeth in dairy cows, including 4 pairs of incisors (no upper incisors) and 8 teeth. The first pair of incisors, the second pair of inner intermediate teeth, the third pair of outer intermediate teeth, the fourth pair of corner teeth, molars are divided into premolars and posterior molars, each side has 3 pairs of 24 teeth. Newborn calves have 1 or 2 pairs of deciduous teeth. Generally, 20 deciduous teeth grow out at the age of 3 weeks, with no posterior molars at the age of 3 ~ 4 months. The difference between deciduous teeth and permanent teeth: deciduous teeth are small and white, with pores between teeth, smooth surface, thin and meticulous teeth, with obvious neck; permanent teeth are large and thick, brown and rough.

.tab {width:100%;border:1px solid # ccc Tab td {border:1px solid # ccc} the first pair of incisors, the second pair of permanent teeth, the third pair of permanent teeth, the third pair of permanent teeth and the fourth pair of incisors at the age of 1.5 to 2.5 years old, the second pair of permanent teeth to 3.5 years old, and the third pair to 4.5 years old. The fourth pair of permanent teeth, 5 years old, the first pair of incisors, 6 years old, the second pair of incisors, 7 years old, the third pair of incisors, 8 years old, the fourth pair of incisors, 9 years old, the first pair of incisors, 10 years old, the second pair of incisors, 11 years old, the third pair of incisors, 12 years old, and the fourth pair of incisors were nearly round.

Control table of age and teeth of dairy cows