据1999年6月23日加拿大《环球邮报》报道，加拿大GUELGH大学研制出三头环保猪。尽管这种猪排出的粪便仍有臭味，但比普通猪的粪便含磷量低20％－50％。含高磷浓度的农家肥是农民常用的肥料，而磷又是水污染的主要因素之一，它能导致江河湖溪中大量藻类的繁殖，最终导致水和鱼失 According to June 23, 1999, Canada's “Globe and Mail” reported that Canada GUELGH University developed three green pigs. Although the stool excreted by this kind of pig is still stinky, it contains 20% -50% less phosphorus than that of ordinary pigs. Farming manure containing high levels of phosphorus is a common fertilizer used by farmers, and phosphorus is one of the major water pollution causes, which can cause large numbers of algal blooms in rivers and lakes and eventually lead to loss of water and fish