What should I do if the sow has not been in estrus for more than 90 days after giving birth to a baby?

The problems of non-estrus, delayed estrus and low litter size of sows after weaning are difficult problems encountered by the pig industry in the world. The current solution is to inject 1000 units of pregnant horse serum into sows on the day of weaning to regulate the endocrine system. The improvement effect is obvious.

Of course, there are some reasons for this problem that must be considered: the pig breeding factor, that is, whether grown sows really grow up sows? Feed factor, whether hormone growth-promoting drugs are added to the feed? Or added drugs to treat eperythrozoonosis? And management factors and so on.