Quality and quantity of water critical for health of livestock
Drought can be a painful reminder of just how important water is. It is the most important nutrient for our livestock and for us as humans. It is also critical for plant growth and forage production. In some cases lack of water at the right time can also create management headaches. During a recent drought, some areas of North Dakota, grazing was not limited by lack of forage, but by lack of water. Grass grew, but potholes, dugouts, and sloughs that had been relied on as a source of water for cattle dried up in the 100ºF heat. Many people quickly discovered how much water a lactating beef cow and her calf can drink in a day when they were forced to haul water to them.
I realize that when you read this issue of Tri-State many of your dugouts and ponds will be covered by 12 to 18 inches of ice! However, in a few short months, cattle will be on pasture and water quality and quantity will be critically important to health and productivity.
Table 1 details the water requirements for various classes of beef cattle. Water requirements for all classes of cattle increase markedly as air temperatures increase. In addition, lactating cows have increased water requirements due to the amount of water that is transferred to the calf in the form of milk. The information in the table assumes average temperatures. Remember, hotter air temperatures will increase water requirements even further.
Animals and humans can quickly become dehydrated if water is limited. This can become a life threatening situation, especially if the animal is stressed or the air temperature is high. Symptoms of dehydration include tightening of the skin, loss of weight, and drying of mucous membranes and eyes. In cattle, the eyes will appear sunken and dull. You may not observe these symptoms until it is too late and some cattle have died. When temperatures are hot, be sure that you routinely check water sources and have an emergency backup plan ready to implement.
Total dissolved solids (TDS) is the most common method by which laboratories report water quality. It is generally expressed in parts per million (ppm). The higher the level of TDS, the greater the quantity of salts dissolved in the water. Dissolved salts may include carbonate, bicarbonates, sulfates, nitrates, chlorides, phosphates, and fluorides.
Sulfate levels are of particular concern, since excess sulfate has been linked to cases of polioencephalomalacia (PEM). In addition, excess sulfate can react with dietary copper making the copper unavailable to the animal. This can result in copper deficiency symptoms, such as reduced immunity and impaired reproduction.
Other potential water quality problems include nitrates, cyanobacteria (blue green algae) poisoning, and contamination from other chemicals. Of these, cyanobacteria poisoning is probably the most commonly reported problem in this area. Cyanobacteria blooms can happen rapidly. In some cases the only warning sign you see is dead mice, muskrats, birds, snakes, or fish near the water source.
Many different laboratories in the region can perform a complete water quality analysis. If in doubt about water quality for livestock use, be sure you have it tested. Routine water testing would include TDS, hardness, and pH. In this region, it’s also a good idea to have the lab perform a sulfate analysis. The costs for routine analyses typically range from $30 to $75 per sample. Most labs have specific instructions for submission of water samples, so it’s best to check with each individual laboratory for detailed instructions and a current price schedule.
Impacts of heat stress and high temperatures
Water requirements increase when temperatures increase. If you need to handle or transport cattle, be sure you so in the morning or later in the evening when temperatures are lower. Placing additional handling stress on cattle during periods of high temperatures will result in additional heat stress and, potentially, mortality. In this part of the world, heat stress is typically minimized because night cooling allows livestock to dissipate body heat. The situation becomes dangerous and potentially life threatening, however, when nighttime temperatures remain elevated, preventing the cattle from dissipating body heat. Lower humidity levels also help. High temperatures with high humidity levels increase heat stress dramatically.
High temperatures increase evaporation from surface water sources. This concentrates the dissolved solids, further exacerbating the problem with poor quality water.
Without adequate runoff, many of the traditional water sources you may have relied on may still be questionable in terms of quality for livestock. It’s important to remember that during drought, evaporation occurs in ponds, sloughs, and dugouts. As the water evaporates, the chemical compounds dissolved in the water become concentrated. This results in a rapid increase in water quality problems which are exacerbated since livestock require greater quantities of water as temperatures increase.
Water is a critical nutrient for livestock. Water quality and quantity can impact livestock performance and animal health. As you look to your grazing plans this summer don’t overlook the value of good quality water and the impact it can have on your bottom line.