Abstract: Sheep is one of the earlier domesticated livestock, which can provide human with meat, wool, milk and other products, and occupies an important position in Chinese animal husbandry industry. Due to the differences in the natural environment and social needs in various regions, hundreds of sheep breeds have been formed in the long-term selection process, each with its own characteristics in appearance and physiological habits. As a phenotypic characteristic of sheep breeds, the horns bear the dual functions:the developed horns not only help the male sheep to improve its position in the population, have priority to mate, but also can effectively resist attacks from natural enemies and protect its population from predation. However, with the popularization of large-scale breeding, the existence of sheep horns is not conducive to the feeding management in the house, which puts forward new requirements for the breeding of sheep breeds. At present, although sheep horns have received extensive attention in actual production and breed breeding, the research on its morphological diversity and genetic regulation mechanism is still insufficient. This review focused on the number and morphology of horns, development process, genetic regulation mechanism and other aspects of current sheep breeds in China, which can not only provide a reference for identifying the mutation sites and major genes affecting sheep horns diversity in the later work, but also lay the theoretical foundation for the breeding of new sheep breeds.

Key words: sheep, horn, morphological characteristics, genetics mechanism