Did you know that milk is made up of 87 percent water?  While many people never step foot on an actual dairy farm, they do reap many benefits from the items produced there.

According to a Wisconsin dairy study, an average American consumes over 200 pounds of milk and 32 pounds of cheese a year. In order to enjoy that cold glass of milk or the cheese on our cheeseburgers, cows need a continuous supply of good quality water in order to continue to produce good quality milk.

Many dairies in Pennsylvania commonly use springs or wells to provide water for their cattle. All water sources used on a farm, especially springs and wells, should be tested annually for things such as iron, sulfates and nitrates.

While these nutrients occur in almost any water source, concentrated levels of any one can cause health issues for dairy cows so it is important to know what exactly you are dealing with.

For example, in southwestern Pennsylvania, it is common for well water to have high levels of iron. A high iron level in the water source can cause iron toxicity. Cows may also accumulate iron sources from dry matter food, but the iron found in water sources is more soluble and can accumulate much more rapidly in the blood stream posing a greater threat to the animal’s health.

Iron toxicity causes an interruption in the absorption of microminerals such as zinc and copper and can lead to abnormal appetite, decreased weight and skin and wound issues. Issues with iron toxicity can cause an increase in the occurrence of mastitis and metritis in fresh cows and affect the overall milk yield.

Other common nutrients that can cause health issues are nitrates, sulfates and manganese. Higher nitrate counts can lead to delay in periods between calving, lower first time conception rates and other reproductive dilemmas in lactating cows. Sulfates and manganese can cause an odor and distaste in the water which limits consumption and in turn again affect milk production.

Another issue common with water quality is bacteria. While a water supply with a normal bacteria count has not shown to affect adult livestock, these circumstances can be extenuated by certain favorable environments and bacteria levels can dramatically increase.

For instance, a water source that has a high iron concentration is an ideal environment for salmonella to grow. Anorexia, diarrhea and weakness occur when cattle ingest water with increased bacteria levels and in very rare cases cows may even ingest certain types of algae which results in death.

In general, these problems seem to affect mature dairy cattle though calves can be affected as well, especially since water is commonly mixed with milk replacer to feed to calves.

Simply providing a quality source of water to animals can greatly reduce health issues and improve the quality of life for the animals. So consider having your water source tested. For more details visit Water Quality for Dairy Cattle.

A dairy water testing program is currently being conducted through Penn State Extension. Results will be presented during the Water Resources Webinar Series on March, 27.

(Written By: Dana Rizzo,Water Resources Educator, Penn State Extension, Westmoreland County and reprinted from the Penn State Extension Watershed Winds newsletter.)

1/7/2013