Before I get into this week’s topic, I want to add some clarification to last week’s article concerning the infestation of New World Screwworm (NWSW) in the US. The one key point that I didn’t mention is that NWSW is not a food safety concern. This is an insect pest and not a disease or food contaminant. This is why the USDA is referring to the current situation as an “infestation” and not an “infection”.
For this week’s discussion I would like to cover the subject of water quality as it relates to the water we provide for our livestock. We understand that water is the single most important nutrient to sustain life, yet there are times we may take it for granted. After all, have you ever been standing in front of the kitchen sink, watching your neighbor get a rain shower that you wish would move a half mile to the north to help your crops out? Water is often the limiting factor for crop growth and yield. Our crops in the field don’t care about the quality of the water, as long as they get it. For our livestock, water availability is crucial, but the quality of their drinking water can be just as important to their health and performance.
There are many quality factors that affect an animal’s water intake and create production losses that may be difficult to pinpoint without testing your water sources. To avoid getting in the weeds, we will break water quality down into three main factors: chemical, bacterial, and nitrate quality. In terms of chemical quality, water pH isn’t usually a problem until you get to the extremes. Most water sources will have a pH close to 7. When pH is less than 5.5 or greater than 8.5, cows can develop mild acidosis which lowers milk yield and depresses milk fat percentage. Ground water is efficient at taking on the properties of the soil it passes through so it is common to find well water that has a high mineral content. This is usually reported as water hardness and salinity. The thresholds for total salinity (salt content) vary depending on the species and stage of production. A soluble salt concentration of 3,000 to 4,999 milligrams per liter is satisfactory for most livestock but can cause some digestive upset in poultry. A level of 5,000 to 6,999 mg/L is safe for most dairy and beef cattle, sheep, swine and horse, but should be avoided for pregnant or lactating animals and is not acceptable for poultry. Major issues can be detected in all species of livestock and poultry when concentrations reach 7,000 mg/L and levels at 10,000 or greater pose a significant risk and it is not recommended to provide this to your animals.
It is generally understood that ruminant livestock have a higher tolerance for potential bacterial water contamination, where poultry, swine and young ruminants are more susceptible to adverse water quality related health issues. Bacterial contamination is more of a concern for grazing livestock that have access to ponds and low flow streams. In confinement housing routine cleaning of waterers, buckets, and bottles reduces most microbial contamination concerns. It is recommended that the total bacteria load be less than 200 parts per million (ppm) and the total fecal coliform count be less than 1 ppm.
Ground and surface water can be a source of excess nitrates. Water testing 100 parts per million (ppm), or less for nitrates typically presents no danger to any class of livestock. The water itself should not cause any issues with nitrate values between 100 and 300 ppm, but if harvested feeds are high in nitrates, the additional nitrate from water may contribute to toxicity issues. Water testing greater than 300 ppm can result in nitrate poisoning and its use is not recommended.
You should periodically submit a water sample, from each of your water sources, for testing. You may have heard the saying that dilution is the solution to pollution. Collect samples from different times of the year as well. You should collect samples in early spring as excessive rainfall may be carrying nutrients from fertilizer and/or manure applications from nearby agricultural fields. You should also collect samples during the summer, as drought conditions can increase the salinity of the water source. In addition to sampling your well water, you should also sample any ponds, creeks, and streams that your animals will have access to. Also, don’t forget about municipal water sources. Some of our facilities are showing some age, and old piping systems can contribute to poor water quality for some.
In closing I want to mention that we will be sending out the next edition of the OSU Extension – Wayne County ANR newsletter on July 1st. We have been working to plan several programs for later this summer and into the fall. You will find a listing of our programs in this edition as well as a few timely articles. If you would like to receive a copy, or have any other questions, contact me at the OSU Extension office at 330-264-8722 or email me at yost.77@osu.edu. I hope you have a great summer.
This article was previously published in The Daily Record.