Cafeteria-style Research

Cafeteria-style research shows
Cows prefer water with iron levels below 8 mg/L

Research conducted at Cornell by water-quality expert Dave Beede has been published in the February Journal of Dairy Science.  In the experiment, Beede and other researchers set up a series of water tubs cafeteria-style, so they could see which tubs the cows preferred based on iron concentrations in the water. Upon first exposure to drinking water, lactating dairy cows tolerated iron concentrations up to 4 mg/L (or 4 parts per million) without a reduction in water intake; however, water intake was reduced with concentrations of 8 mg/L.

They also indicated that the direct livestock suitability water analysis used by some labs may underestimate the amount of iron in the water as some of the iron is chemically associated (bound) with other chemicals in the water and not analyzable. Therefore, what may appear as a favorable 2 mg/L level may actually be an inhibitory 8 mg/L level.

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Conventional nutritional opinion claims that animals do not have the ability to balance their nutritional needs when given the choice.  Yet, these researchers relied on the nutritional wisdom of these cows to set their own standards for acceptable levels of iron in their water by providing varying concentration of iron in water “cafeteria-Style”.

Reading between the lines, this experiment also shows that laboratory tests are not as accurate as an animal’s nutritional wisdom ---   “some of the iron is chemically associated (bound) with other chemicals in the water and not analyzable.”. However, when given the choice, the cows didn’t have any problem choosing the level of iron acceptable to them.

And taking that one more step: maybe cows really are smarter that some scientists.

Hopefully more researchers will begin to apply common sense in their research and the interpretation thereof.