母猪发情的表现很多，养猪户要学会辨别。通常母猪发情时会叫唤爬墙，但也不排除有些安静的母猪。而眼泪过嘴巴的现象也有可能不是因为发情，而是舍内的空气质量不好，氨气重。
There are many manifestations of sow estrus, and pig farmers should learn to distinguish them. Sows usually call for climbing walls while estrus, but they do not exclude some quiet sows. And the phenomenon of tears over the mouth may not be due to oestrus, but the air quality inside the house is not good, ammonia is heavy.
次发情的猪在发情时通常阴户肿胀，但经产母猪则不太明显。所以，并不是所有母猪都有这类的发情行为表现，我们可以用一种简单的方法来鉴定，就是母猪的排泄。
Pigs in the first estrus usually have swelling of the vulva during estrus, but the sows are not very obvious. Therefore, not all sows have this kind of oestrus behavior, we can use a simple way to identify, that is, the excretion of sows.
一般来说母猪会定点排泄，就算是没有好的母猪，也会留一块干燥的地方让自己休息。所以，其实当母猪在圈里开始胡拉胡尿的时候，就是发情了。
In general, sows will be excreted at regular intervals. Even if there is no sowing good sow, there will be a dry place for rest. So in fact, when the sow starts to Hula Hu in the circle, it is estrus.
从猪的生物学特征上来看，野生母猪发情时，会通过排泄粪尿来散发自己的气味，吸引公猪。由于人工猪舍限制了自由，母猪发情时，就只有在狭窄的猪舍里乱拉屎尿，希望气味引起公猪的注意。
From the biological characteristics of pigs, wild sows will emit their own odors and attract boars when they are in oestrus. Because the artificial pig house restricts freedom, when the sows are in oestrus, it is only in the narrow pig house that they shit urine, hoping that the will cause the boar's attention.
