It is crucial for breeding farms to improve their economic efficiency. There are too many cocks in the flock, eating much, fighting each other and interfering with breeding. The fertilization rate of the eggs is not necessarily high. If the cock is too small, the feed can be saved, but the cock can hardly afford the task of mating with each hen. Because of the large number of chickens, the fertilization rate of eggs is also low. Therefore, in the case of large groups of free mating, maintaining a reasonable ratio of male and female is a problem worthy of attention. It is now generally accepted that ratio of male to female is 1:12-15, that is, for every 120 to 150 hens in the flock, 10 cocks are placed, and the ratio of male to female of medium-sized laying hens is 1:10-12, ie every 100-120. Only 10 cocks were placed in the hens to ensure a satisfactory fertilization rate. Under the condition of cage breeding and artificial insemination, the breeding burden for each rooster is 35-40 hens, ensuring that the fertilization rate of the breeding eggs is above 90%. The above ratio of male to female refers to large groups. If the number of cock is too small, although the fertility rate can be guaranteed, it is difficult to guarantee germplasm. The same chicken species, the number of chicken farms is not large, there are not many breeder cockerels, and the breeders will be produced in the future. The quality is certainly not as good as the number of chicken farms. In order to ensure that chicken breeds should have a level of production performance, it is recommended that small-scale breeder flocks be raised and that they should raise more male cocks. In order to prevent cockroaches, the same group of cocks should be changed together in accordance with a reasonable proportion of parents. Or withdraw together, can not be mixed. Although the number of matings per hen to a hen was reported to be 20 to 30 times per day, it was observed as 0 to 41 times. However, according to our observations on the bred population of Qingdao Airlines, the average time from one day to the next day is 5.8 to 7.7 times per day, with a range of 2 to 12 times. During the afternoon, the frequency of feeding and management of the eighth-chapter breeder chickens accounted for 73.7% of the total number of matings at 3-7 o'clock in the afternoon, and it was concentrated at 5-7 o'clock, accounting for 47.4% of the day. According to observations, chickens were busy eating in the early morning, and then they began to enter the nest and lay eggs. They did not like to mate and even ignored the cocks. After 3 pm, most hens had already finished laying eggs and began to accept cock mating. Two hours before sunset, the hens all went to the sports field. The sex activities of the male and female chickens were very strong. Some hens even took the initiative to attract males to mate. A total of 7 cocks were found within 5 hours to 6 hours, including 4 hens between 5:50 and 5:57 with a minimum interval of 1 minute. This phenomenon of natural mating of roosters is also consistent with the conclusion that the optimal timing of insemination after artificial insemination is after 3 pm.