What causes foaming at the mouth?
Foaming at the mouth is a sign of sham chewing (stereotypical behaviour). The sow isn't (or wasn't) feeling well. Stereotypical behaviour is comforting to the animals due to the release of morphine-like substances.Once they start, they keep doing it.If many sows in the pen are sham chewing,look for the cause. Does the feed provide a satisfied feeling? Are they waiting to be fed at the feeding station? Is something wrong with the climate? Are the sows unable to flee from a dominant sow? Do they have enough lying space?
這是老外對這種“空嚼”現象的看法。翻譯如下：
什么原來引起嘴里這么多的泡沫呢？
嘴里泡沫是空嚼的特征（模式化機械的行為）。母豬感覺不好。這種機械的行為的產生是因為嗎啡樣物質在體內釋放的結果。一旦開始，行為就持續下去。如果有一頭母豬發生空嚼現象，就必須要找原因，是不是飼料不能滿足？是不是她們在等著喂料？是不是氣候影響的？是不是母豬沒辦法逃避具有統治地位的母豬？是不是母豬沒有足夠的地方躺下？