What to do when a five-month-old gilt refuses to mate in heat

    The reason for refusing to mate may be that the sow's estrus period is short and she has already entered late estrus, when her sexual desire declines, or she may have already mated. Therefore, you must constantly pay attention to the sow's every move, find sows in heat in time, and mate them at the right time. 

In China's rural areas there are four proverbs about the right time to mate a sow: (1) when the vulva is smeared with grass, insemination is just right; (2) when the expression is dazed, insemination will result in conception; (3) when she stands still, it is exactly the right time to mate; (4) when the mucus becomes thick, the timing is just right.