horse

English name horse

The mammal Equisetum Chiroptera is a herbivorous livestock. In ancient times, horses were the main driving force of agricultural production, transportation and military activities. With the invention and wide application of power machinery, the service value of horses has obviously declined in some industrialized countries, and almost all field operations have been replaced by tractors. Horses are mainly used for equestrian sports and milk and meat production, and the breeding quantity has been greatly reduced. However, in some developing countries and regions, horses are still mainly used for service and are an important source of service strength.

The origin and domestication of horses originated from Cenozoic and Early Tertiary 60 million years ago. Its primitive ancestor was a protohoofed animal, with a short stature, five toes on each limb and a well-developed middle toe. Shi Xinma, or ancestor horse, who lived in the early Eocene of Tertiary 58 million years ago, was about 40 cm tall. The forelimb is low and has four toes; The hind legs are high and have three toes. Simple teeth, suitable for tropical forest life. After entering the Miocene, the dry grassland replaced the wet shrub, and the function and structure of the horse changed obviously: the physique increased, the limbs became longer and became single toe; Teeth become hard and complicated. After the gradual evolution of Singapore-Malaysia, China-Singapore-Malaysia and Shanghai-Singapore-Malaysia, it was not until the Quaternary Pleistocene that a single-hoofed, tall Malaysia appeared.

Domestic horses are domesticated by wild horses. China was one of the first countries to domesticate horses. From the relics of Dawenkou culture period and Yangshao culture period in Shandong and Jiangsu in the lower reaches of the Yellow River, it is proved that several wild horse breeds have been domesticated as domestic animals around 6000 years. Horses were domesticated later than dogs and cows.

Different breeds of horses with different biological characteristics have great differences in body size. Heavy variety weight 1200 kg, height 200 cm. The small variety weighs less than 200 kg and is only 95 cm tall. The so-called pocket pony is only 60 centimeters tall. The head is straight and long and the ears are short. The limbs are long, the bones are solid, the tendons and ligaments are developed, and cicadas with palm and pillow traces (commonly known as night eyes) have hard hooves and can run quickly on hard ground. The coat color is complex, mostly dark brown, chestnut, blue and black. Take off the quilt in spring and autumn. Developed sweat glands are conducive to regulating body temperature, not afraid of cold and heat, and easy to adapt to the new environment. The chest is deep and wide, with developed heart and lungs, suitable for running and strenuous labor. Esophageal stenosis, single stomach and large intestine, especially cecum, are extremely developed, which is helpful to digest and absorb coarse grains. Without gallbladder, bile duct is developed. The chewing ability of teeth is very strong, and the gap between incisors and molars is called occlusal part, which is used to hold the occlusal body when driving. According to the number, shape and wear degree of teeth, the age can be determined (Figure 3), and the hearing and smell are keen. The distance between the eyes is large, and the overlapping part of the visual field is only 30%, so the judgment of the distance is poor; At the same time, the eye's focal length adjustment ability is weak, and it can only form a blurred image for objects 500 meters away, but it can distinguish the shape and color of nearby objects well. The head and neck are flexible, and the visual area of both eyes reaches 330 ~ 360. There is a photosensitive film on the outer layer of the fundus retina, which has strong sensitivity and can see the surrounding objects clearly at night. Horses are easy to train. Through the sense organs such as hearing, smell and vision, a firm memory can be formed. The average life expectancy is 30 ~ 35 years old, and the longest can reach more than 60 years old. The service age is 3 ~ 15 years old, and some can reach 20 years old.

There are more than 200 kinds of horses in the world, and there are more than 30 kinds in China. It can be mainly divided into local small varieties, riding type, fast-paced type, heavy-pulling type and both-pulling and riding type. Feeding management methods mainly include herd management, house feeding management and pony training and cultivation.

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