Cattle are more susceptible to this problem than pigs, because bacteria in the rumen convert nitrate to the much more dangerous nitrite. Some strains of bacteria which contaminate well water can also convert nitrate to nitrite. Nitrates and nitrites in water impair the use of vitamin A by the pig and reduce overall animal performance. However, the levels required to affect performance occur so rarely that there is little cause for concern under practical conditions. Although pork producers should be aware of the potential hazards of nitrates to livestock, they pose a greater risk to humans who consume contaminated water, especially infants.
Nitrates are often a man-made problem.
They are also persistent. Examples of barns torn down three decades earlier still causing nitrate problems have been documented. Sulphates - Sulphates are the primary cause of quality problems in well water on the prairies. Sulphates are not well tolerated in the gut of the pig, resulting in diarrhea and possibly reduced performance. Weanling pigs are most susceptible.