Causes of non-estrus or repeated mating infertility in sows

The first is reproductive tract inflammation (70 to 80%), of which the incidence of uterine inflammation is higher. The second is the lack of vitamin A, D, E, minerals and trace elements in feed for a long time, which can cause normal estrus and non-ovulation in sows. The third is early embryo death, which is due to the lack of progesterone, which leads to the early death of fertilized eggs due to lack of nutrition and lack of implantation, mistakenly thinking that it is not registered. The fourth is that inbreeding can lead to repeated infertility. The fifth is abnormal structure of reproductive organs, resulting in congenital infertility. Sixth, when the temperature is above 35 degrees, the motility of boar sperm decreases, making it difficult to conceive.