With an ever increasing population, the global demand for agricultural products such as meat, milk, and eggs is expected to double by 2050. With increased demand comes increased livestock production and stress on limited resources such as land and water. Globally, livestock production accounts for 40% of agricultural output and is the primary use of land and freshwater.

Around the globe, 30% of the land surface is used for agriculture, and in the United States, more than 45% of the total available land is used for agriculture. According to the Council for Agricultural Science and Technology, these agricultural practices account for 70% of fresh water usage globally and 38% of freshwater withdrawals in the United States.

In the United States more than 60% of the total livestock water usage is pulled from ground water sources and only 1% comes from freshwater withdrawals. Texas, California, Oklahoma, and North Carolina collectively make up 35% of the total livestock water usage. Interestingly, USGS data shows that there was a 7% decrease in total livestock withdrawals in 2010 from 2005. This is partly a result of better regulations and on-farm water management practices, and shows how these practices can improve water usage and conservation.

Livestock Water Usage
Livestock water usage includes the animals’ daily drinking requirements, water used for growing feed, feedlots, dairy operations, and other on-farm needs. Other on-farm livestock water usage includes:
• Waste disposal systems
• Cooling of facilities that animals are housed in
• Cooling of animal products such as milk
• Wash down of facilities and dairy sanitation
• Incidental water losses

Each species of livestock has different water requirements. These requirements can vary depending on a variety of things including quality of forage, environmental temperature, water quality, age, rate of gain, pregnancy and lactation, activity level, type of diet, and overall health of the animal. The average water requirements for the different types of livestock, excluding poultry, based on the environmental temperature and level of production can be found at North Dakota State University’s 2015 publication on Livestock Water Requirements.

Factors That Affect Water Quality
Drought is the number one cause of poor water quality. With drought comes less water and dry air. Dry air causes stock ponds to evaporate and become saturated with salts and algae that can lead to livestock death. Less water also leads to more usage from ground water sources which can also cause the water to become saturated in salts and algae, especially if it is coming from a shallow ground water source.

Salt
Livestock are extremely susceptible to salt concentrations once they reach a certain level. During drought, pastures that only have stock ponds as a drinking source should be grazed early in the season before they undergo extensive evaporation. Livestock water consumption also tends to be lower early in the season as a result of the cooler temperatures.

When water quality is poor, livestock will reduce their water consumption by being less active. However, if an animal gets thirsty enough it may drink a large quantity of salty water at once, which can cause the animal to die rapidly.

Blue-green Algae
During hot and dry weather algae can multiply rapidly, and under right conditions stock ponds can become saturated in lethal concentrations of blue-green algae. Wind can also cause shorelines of larger bodies of water to become saturated with algae. Animals that drink water saturated with blue-green algae can die within a few yards of the shore or may suffer for a day before succumbing.

The cause of death in these situations can be tricky, because a change in wind directions can blow the concentrated algae away or to other shorelines, making the water safe to drink again in that particular area. Identification of blue-green algae requires identification through the use of a microscope, and will require samples to be taken in for testing.

Improving Livestock Water Productivity
Providing quality forage and fresh clean water is the number one factor for improving efficiency of water usage. Livestock not only get their water requirements from drinking, but also from the forage they eat. If livestock are forced to eat dry plant matter they will require more drinking water. Certain plants such as greasewood and salt grass are naturally high in salts and will have even higher concentrations during times of drought. If livestock are forced to eat it, their water consumption will increase, and if that water is becoming saturated with salt, it can quickly lead to salt toxicity and death.
The opposite can be said for livestock that have access to good quality forage and clean water. Livestock that are allowed to graze on pasture with a variety of plants and grasses will consume less water because they are getting more from what they eat.
Water conservation can also be improved through vegetation management. Good quality pasture results in increased infiltration and reduced evaporation and transpiration of rain water. It also results in less runoff, allowing for increased uptake of water by vegetation.

Proper management of livestock numbers and grazing has major impacts on livestock water use and pasture vegetation. For example, cattle are known to over graze areas around water resources which causes a decrease not only pasture quality, but also water quality. In large grazing pastures, quality foraging land may be underutilized because the areas are too far from water resources. In these cases the livestock water productivity and conversion rates are significantly reduced.
Livestock water productivity and land management can be improved by balancing the distribution of water and feed sources. Many livestock farmers approach this problem by drilling wells and/or diverting water to separate areas through buried water pipe. This not only balances the water resources with the amount of pasture, but also allows for better water quality and management. It also makes it so the livestock cannot wade in their drinking water.

While this may take some time and effort, in the long run livestock water productivity and pasture quality can be increased. This can result in an overall increase in livestock conversion rates, just as long as there isn’t too many livestock per acre for the region in question.

To prevent the degradation and erosion of land and the pollution and over usage of clean water resources, it is essential for ranchers and farmers alike to help create and implement a sustainable and integrated approach to livestock and feed crop production. In addition to sustainable management of water and land quality, it also includes practicing environmentally safe and sustainable manure management, nutrient application, and irrigation.