Calf breeding is one of the main bodies of animal husbandry in China, and how to improve the survival rate of calf breeding is a problem encountered in the current development. Calves generally refer to calves born in April-June. Breeders should pay special attention to the health of calves in these months. The health of calves is related to the economic benefits of the whole calf breeding industry.
With regard to the origin of other cattle breeds, Keller (1909) once thought that bos frontalis was domesticated by Javanese bison. However, according to the study of skull types and horns in modern times and the analysis that the crossbreeding between tumor cattle and ordinary cattle can produce offspring and breed new varieties, it is proved that tumor cattle also originated from the original cattle, and its domestication time in South Asia is roughly the same as or a little later than that of ordinary cattle. The characteristics of the "cow" recorded in China ancient books, that is, the modern buffalo China Buffalo, are very similar to the Indian wild buffalo in terms of coat color, skull and horn shape. Therefore, scholars previously believed that China buffalo originated from the Indian wild boxer cow-Bubalius Arn. However, recent studies on the fossils of at least 7 species of buffalo unearthed in different stages of the Pleistocene in North China, Northeast China, Inner Mongolia, Sichuan and other places have proved that at least 1 ~ 2 of them have evolved into modern domestic buffaloes. China buffalo originated in the south. This may be due to the glacier attack in northern Asia in the late Pleistocene, which made the vast area north of the Yellow River basin in the past tropical, dry and cold, and forced the ancient buffalo and other animals to migrate to the south. China yak is domesticated from wild yak.
According to the unearthed skull fossils and murals left over from ancient times, it can be proved that ordinary cattle originated from Bos primie-nius and were domesticated in the Neolithic Age (Figure 2 [original cattle]). The remains of cattle were found in West Asia, North Africa and continental Europe. Most scholars believe that ordinary cattle were domesticated in Central Asia at the earliest, and then extended to Europe, China and Asia. Asia is the habitat of bison. Up to now, many of them still live in the wild, while in Europe and North America, bison have disappeared except for a few zoos and protected areas. Fossil materials of the ancestors of China Yellow Cattle have also been found in many places in the north and south, such as the bull's head bones displayed in Datong Museum, which have been identified for 70,000 years. The bone core about 1 m in the Anhui Provincial Museum was unearthed in the late Pleistocene strata in Huaibei area. In addition, in Yushu county in the northeast, the fossils of the original cattle and the remains of bison were found ten thousand years ago.
Great changes have taken place in the appearance, biological characteristics and production performance of domestic ordinary cattle. Bison is tall (height 1.8 ~ 2. 1 m), wild, with single coat color, mostly black or white, small breasts and low milk yield, which is only enough for calves. Domestic cattle are smaller than bison (body height 1.7 meters or less), gentle in temperament, diverse in coat color, enlarged in breasts, and greatly improved in milk yield and other economic performance.