Water is one of the most valuable resources on any farm, yet poor water quality can quietly undermine both livestock and crop production.
By Roelof Bezuidenhout
If your animals, pastures or lands are not performing as expected, water quality should be one of the first things you check. Even if the water tastes acceptable, testing is essential. Some problems can be managed, but others cannot, so it’s important to understand the risks.
How Poor Water Affects Livestock
Poor-quality water can significantly slow growth in young animals and impair reproduction in adults. Borehole water in particular may contain substances that are harmful to livestock and can even be passed on to young animals through milk.
Water quality is influenced by components that affect taste as well as substances that may be hazardous or toxic. A salty or brackish taste usually indicates high levels of dissolved solids. A sulphur smell may or may not be harmful. More concerning are trace elements that have little effect on taste but can disrupt digestion, reduce feed intake and affect animal health.
Although animals can tolerate higher levels of sulphate, chloride and sodium than humans, there are limits. In some areas, borehole water contains arsenic, mercury or selenium. Even low nitrate levels, over time, can cause abortions.
Hot weather worsens the problem: Evaporation from drinking troughs concentrates toxins, increasing the dose animals ingest; and water can become extremely hot during summer – too hot to touch, let alone to drink.
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What Can Be Done
Removing toxic elements from water is generally not feasible, but there are ways to reduce the impact of poor-quality water:
Dilution: Salty borehole water can sometimes be diluted by mixing it with fresher water from a dam, river or another borehole nearby. Water quality can vary significantly over short distances due to geology.
Improve replenishing of groundwater: Building stone barriers across watercourses upstream of a borehole can slow runoff and allow more rainwater to seep into the aquifer, improving salinity levels. Avoid using old tyres, which can contaminate groundwater.
Reduce evaporation: Cover brick or concrete reservoirs with netting or corrugated-iron sheets to limit evaporation, which increases salt concentration.
Lower the temperature: Bury at least the last sections of the pipes leading to troughs, or paint the pipes white. This considerably reduces the temperature and can event prevent pipes from bursting as a result of hot water.
Managing Drinking Water For Animals
Good water management is just as important as water quality:
- Ensure sufficient water is easily accessible to all animals. Troughs should refill quickly and not force animals to compete.
- Place troughs on raised areas or stone paving to reduce mud and damage.
- Allow for adequate daily water needs. Provide 10 litres per animal per day for sheep and goats, and 60 litres for cattle. Take losses from leaks and evaporation into account.
- Reservoirs should hold enough water for several days in case supply is interrupted. Animals can survive briefly without food, but not without water.
- Clean troughs regularly. Dirty water can contain algae, parasites, droppings and urine, all of which reduce intake and performance.
- Temporarily fence off polluted open water sources such as dams and river pools when water stagnates, usually during times of drought, and quality deteriorates.
Saline Soils – Prevention Is Better Than Cure
Irrigation inevitably concentrates salts in the soil. Once salinity exceeds a certain level, yields decline – slowly at first, then to the point where cropping becomes uneconomical. Saline soils, often visible as white deposits on the surface, should not be irrigated with salty water, as this accelerates degradation.
Reclaiming saline soils is possible but extremely costly. The best option is prevention. Avoid irrigating saline land altogether, and consider drought-tolerant fodder crops such as spineless cactus pear (Opuntia ficus-indica, formerly known as prickly pear) and old man saltbush (Atriplex nummularia). These require minimal cultivation, survive on rainfall alone and provide reasonable nutrition. Cactus pear has the added advantage of a very high water content, significantly reducing animals’ drinking water requirements.
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 | Roelof Bezuidenhout is a fourth-generation wool, mohair, mutton and game farmer and freelance journalist. Attended Free State University, majoring in animal husbandry and pasture science. Other interests include agricultural extension and rural development. |
