Water is the second-most important nutrient, behind oxygen for livestock. It accounts for 98 percent of all molecules in the body and between 50 and 81 percent of an animal’s total body weight at maturity. Mammals can only lose about 10 percent of their water weight without risking extreme illness or the potential of death.
So, it’s vital to ensure livestock and poultry have access to high quality and high volumes of water to ensure their wellness and productivity.
Water is critical to many body functions, including the following:
Water also plays a role with tissue maintenance, eye development, thermal regulation, mineral homeostasis and body pressures.
Dehydration can be caused by poor management practices, such as not ensuring an adequate volume of water is flowing to water troughs and water nipples, or that water lines are plugged and not flowing properly, especially during warmer weather. Dehydration can also be caused by poor water quality, or animals not being trained on a new water source.
In the late part of the summer, water sources prone to runoff can become contaminated with blue-green algae. The algae impacts the taste of the water and animals will be less willing to drink. In the case of swine, it can actually make piglets feel sick, especially nursery pigs.
When animals are introduced to a new water supply (trough or nipple), their water intake may decrease because they are not trained to drink from the new source. To remedy this, producers can allow a small trickle of water come out of the trough or nipple so that the animal can find the water source.
Dehydration can have a negative effect on many production factors on a livestock operation. Dehydration can weaken tight junctions, gut integrity and reduce the strength of an animal’s epithelial tissue. When this happens, inflammation issues may arise for the animal as they become more susceptible to disease and infections.
Animals that become dehydrated also suffer from poor production, including lower growth rates in livestock, and reduced milk production in dairy cattle. Dehydration usually leads to a decrease in feed intake, thus reducing growth rates in cattle, swine and poultry.
Water is a critical component of milk production, since water comprises 87 percent of milk. As a result, lactating dairy cows that become dehydrated will experience near cessation of milk production.
Dehydration in swine can result in salt poisoning, which can be fatal. A normal salt concentration in swine nutrition becomes toxic in the absence of water. Pigs affected by salt poisoning will be uncoordinated and have intermittent convulsions. The worst clinical signs and fatalities occur if water is given to pigs after a period of restricted water intake or dehydration. It’s important to provide access to water sparingly until they are fully rehydrated.
Dehydration can especially be a problem for endurance animals, like racehorses, during warmer weather. When you put an animal through long endurance training or racing tactics, they can become dehydrated if they’re not drinking enough water before or after those events. Just like in human athletes, this increases gut leakage and the breakdown of tight junctions on the epithelial barrier of the gut. This allows harmful bacteria, pathogens and breakdown products of specific bacteria called endotoxins into the bloodstream, which then causes inflammation and sets off another cascade of problematic events.
There are both physical signs and behavioral signs that can indicate if an animal is dehydrated. Common signs include lethargy, tightening of the skin, weight loss and drying of mucous membranes and eyes.
When dairy and beef cattle become dehydrated, the eyes will appear sunken and dull. As mentioned earlier, dehydration in lactating dairy cows results in a near cessation of milk production.
In horses, dehydration results in a reduction in skin elasticity. You can check this by pulling the skin over the shoulder and holding it for a moment. Release the skin and count the seconds until the fold disappears. If the horse is dehydrated, the skin will stand for several seconds.
In swine, signs of dehydration include thirst, constipation, skin irritation and lack of appetite, often followed by nervousness, apparent deafness and blindness.
Some behavioral signs of potential dehydration include the following:
There are several things that livestock and poultry producers can do to ensure their animals stay hydrated, including the following: