This case study was handled by Lynn Davis, dairy nutritionist from Neenah, Wis. He is affiliated with Nutrition Professionals Inc.

Parts of eastern Wisconsin have a unique geological feature known as the Niagara Escarpment. It is a rock formation that begins in western New York and extends all the way to Lake Winnebago in Wisconsin. Some of the dairies located on the Niagara Escarpment have had to drill deep wells in order to reach a large underground aquifer.

It didn’t take long for nutritionist Lynn Davis to learn about this when he moved to eastern Wisconsin in the early 1980s.

One of his early clients struggled with low milkfat levels. Overall milk production wasn’t that great, either. Yet, the farm was generally well-managed and had an excellent base of forages and corn grain. Because of the excellent feed supply, Davis initially suspected that the cows were getting too much concentrate, which would explain why milkfat levels were depressed. But changing the ration did absolutely nothing to correct the problem. Obviously, his initial diagnosis was wrong.

Starting again from scratch, Davis went through all of the possible rule-outs. He ran some water tests and was surprised at the results. Among other things, the water contained extremely high levels of total dissolved solids, sulfate, chloride and sodium. “I had never in my life seen water like that before,” he says.

He was motivated to correct the problem. He talked to a well-driller, who informed him there was a source of water on the property that could be accessed at a shallow depth rather than the deep-water wells the farm was currently using. When the farm switched to the higher-quality water, production immediately began to improve: It was like a light switch had been turned on, Davis says.

That prompted him to learn more about the Niagara Escarpment and the implications it has for water quality in the area. He even brought in hydrologists to speak to farmers at educational seminars.

Much of the rock comprising the escarpment is dolomite rock, with high levels of magnesium sulfate and other minerals that leach into the groundwater over time.

Now, fast-forward to the present...

One of Davis’ current clients — a dairy with 30 times more cows than the previous client — was aware of the escarpment when it first sought a permit to build in eastern Wisconsin. But the state Department of Natural Resources (DNR) recommended that the dairy dig deep wells because of the dairy’s size and the possible impact it could have on neighboring wells if the dairy dug at a shallow depth.

The dairy dug a test well and everything looked great. Monthly reports after that were positive, as well. Then, several months after the animals arrived and production began, things changed. One test came back 3,000 parts per million of total dissolved solids, 1,200 to 1,500 parts per million of sulfate, 400 parts per million of chloride, and 200 parts per million of sodium — all way in excess of standard guidelines for good-quality water.

The farm owner was very disappointed with this turn of events, since he had done his due diligence and had complied with the DNR request.

As to why it happened, Davis said the only explanation is that the farm is large enough that it may have created enough of a draw on the aquifer that it literally moved water from one location to another, which changed the quality.

The dairy has struggled with this issue, especially involving the newly arriving animals, such as bred heifers. Dry matter intake among the heifers is very low — only about 60 percent of what would normally be expected for late-gestation heifers. Performance among the adult cows is average or maybe a little above average. So, it appears there is some sort of adaption to the water taking place once the animals have been at the farm for a while.

The dairy looked at various water-treatment options, but found them to be cost-prohibitive.

Meanwhile a well-driller found a large supply of water — at shallow depth — on a back corner of the property. That prompted the farm to run a side-by-side comparison, with one pen of 300 multiparous cows receiving water from the new well at a shallow depth and another pen receiving water from the deep wells already serving the farm. The results were remarkable, Davis says. After 67 days, the cows receiving water from the new well had higher production — 5.5 pounds of milk per cow per day, on average — and were eating about 3 pounds more dry matter per day.

The farm has received a temporary permit from the DNR to use water from the new well and is working on something more permanent. DNR has been very cooperative, Davis notes.