Water has been described as the most important nutrient for dairy animals. It’s a critical element to keep animals healthy and producing efficiently. Alejandro R. Castillo, Ph.D., Extension Dairy Farm Adviser and dairy nutrition expert at the University of California, Davis explains, “Water is essential for digestion, transport of nutrients and for the elimination of wastes and excess body heat.”

 

Although sufficient, clean, high quality drinking water is critical during all seasons, it is especially important during hot weather. In the summer, cows consume much more water to control body temperature and stay cool, he says. Dr. Castillo emphasizes that cows should never be made to wait to drink water when they want it. 

There isn’t much research available on water contaminants and their effects on dairy cattle performance,but Dr. Castillo says that the National Research Council defines water quality for both humans and livestock based on the following criteria:

 

• Odor and taste

• Physiochemical properties, including pH, total dissolved solids, total dissolved oxygen and hardness

• Presence of toxic compounds, including heavy metals, toxic minerals, organophosphates and hydrocarbons

• Presence of excess minerals or compounds such as nitrates, sodium, sulfate, iron and others

• The presence of microorganisms, including bacteria, viruses, protozoa or parasites

 

Providing adequate and clean water to your animals in an uncrowded environment is a necessary animal welfare practice, says Ricardo Chebel, DVM, MPVM, a dairy veterinary expert at the University of Minnesota. “Water troughs that are extremely dirty, contain water that has a bad odor or color, or are contaminated with feces or feed is not only a welfare issue, but something that will also impact health and production,” says Dr. Chebel. Dirty water  troughs can expose cattle to bacteria. For example, coliforms Salmonella and E. coli 0157 have been isolated from livestock water in California, Dr. Chebel explains.

Dr. Castillo recommends that you try to clean water troughs weekly. He also suggests that you have your dairy’s drinking water source analyzed annually for a complete chemical composition, preferably prior to the summer season. This analysis should include salinity, total dissolved solids; total soluble salts (see Table 1), hardness,nitrates (see Table 2), sulfates, pH, and other nutrients and contaminants, such as trace minerals, arsenic, or other heavy metals. The analysis should also include a microbial analysis for coliform and other microorganisms.

 

Nutritionally, Dr. Castillo says that minerals in the water should be included in the diet for mineral balances and to reduce mineral excretion into the environment. “The new environmental regulations coming from the U.S.  Environmental Protection Agency indicates that all the nutrients should be controlled through a Nutrient Management Plan (NMP),” says Dr. Castillo.

 

While these regulations are being mandated on the federal level, individual states are responsible for developing their own NMPs. Not all states have finished developing their NMPs, but California is one dairy state that has,  according to Dr. Castillo. This plan currently regulates the amounts of nitrogen, phosphorus and potassium that can be released into the environment from livestock facilities. In the future, other minerals identified as possible  pollutants, or with potential effects on crops and the environment, may be added to the NMP.