When thinking about livestock nutrition, we often focus on animal feed. But how often do we consider the quality of drinking water for livestock? Water is arguably the most crucial nutrient for livestock. Poor water quality can significantly impact both animal health and performance. Today’s blog explores why water quality is essential for livestock and which water parameters are important to monitor.
Importance of Quality Water for Livestock
Water is the most critical nutrient for livestock. Low water intake reduces animal performance more severely than any other nutrient deficiency. Water needs vary depending on weight, age, diet, reproductive status, and weather conditions. Here are the estimated daily water intake requirements for different types of livestock:
Unfortunately, water is often an overlooked aspect of livestock nutrition, yet it is vital. While animals and humans can survive for extended periods without food, they cannot live without water for more than a few days. In livestock, water serves several critical functions, such as:
- Removing waste products from digestion and metabolism,
- Regulating body temperature and blood pressure,
- Producing milk and saliva,
- Transporting nutrients, hormones, and other chemical messages throughout the body.
As much as water intake is important, so is the quality of water for livestock. Livestock can tolerate lower-quality water better than humans. But, high concentrations of certain substances in water can harm them. Even if livestock don’t show clinical signs of illness after drinking poor-quality water, their growth, lactation, and reproduction can suffer.
Research indicates that providing high-quality water to livestock can reduce disease incidence. Also, livestock given access to clean water tend to drink more, eat more, and gain weight more quickly. For example, a study conducted in Alberta, Canada, found that calves drinking from a clean trough gained 9% more weight than those drinking directly from a pond.
Essential Parameters in Water for Livestock
Total Dissolved Solids (TDS), or salinity, is a primary indicator of water quality. It measures the concentration of dissolved inorganic salts in water. Livestock can adapt to a certain level of mineralised (salty) water, but sudden changes in TDS levels can be harmful. The main symptom of consuming saline water is diarrhoea. If TDS levels are too high, cattle might avoid drinking water for a few days. Water avoidance is followed by a period of high consumption that can lead to illness or even death (within 24 hours). In terms of TDS levels:
- Less than 1,000 mg/L is considered acceptable for all livestock.
- Between 1,000 and 7,000 mg/L may have varying effects (from no noticeable impact to temporary diarrhoea or decreased productivity).
- Between 7,000 and 10,000 mg/L can cause severe health problems and water refusal.
- Above 10,000 mg/L should never be used for livestock.
A pH level of 7 is neutral, although most water livestock consume is mildly alkaline (pH > 7). Water with a pH range of 6.0 to 8.5 is generally acceptable for most livestock, but the preferred range is between 6.8 and 7.5. Acidic water (pH < 5.5) can lead to acidosis, which can result in liver abscesses or even death. On the other hand, highly alkaline water (pH > 10) can cause digestive and physiological problems, including diarrhoea, poor feed conversion, and reduced water intake.
Water temperature can influence livestock water intake. Research has shown that cool water helps livestock maintain body temperature and increases water intake. As such, it can lead to better weight gain. Cool drinking water may be achieved by using deep dugouts or groundwater sources.
Nitrates are naturally occurring and soluble, moving with runoff water. As a result, ponds and shallow wells near heavily fertilised or manured fields are vulnerable to high nitrate levels. While nitrates themselves are not too toxic, bacteria in ruminant animals can convert them to nitrites. Nitrites can reduce the blood’s ability to carry oxygen, leading to shortness of breath and potentially suffocation.
Acute nitrate toxicity from water alone is rare but becomes a concern when combined with high nitrate forages. This combination can reach toxic levels and cause death within hours. Chronic nitrate toxicity is more common in water. This can result in reduced weight gain and increased susceptibility to infection and miscarriage.
Water analyses typically report nitrates and nitrites together. For cattle, the recommended limit is 100 mg/L as nitrogen (N) or 450 mg/L as nitrates (NO3). While these levels are uncommon in surface water, they are more frequently found in contaminated groundwater.
High concentrations of sulphates can be present in surface water from saline areas and groundwater-fed sources. High sulphate levels reduce the availability of copper, zinc, iron, and manganese in the diet. Loss of these trace minerals leads to slowed growth, infertility, and weakened immune response.
Very high sulphate levels can also cause neurological diseases. This is because sulphates in the rumen are converted to sulfides. Sulfides can kill bacteria that produce thiamine (neuroprotectant) or be directly toxic to the brain.
- 500 mg/L: May affect calves, but they usually adapt over time.
- 800 mg/L: Can cause mineral deficiencies and related health issues.
- 1,000 mg/L: May cause vitamin B1 deficiency, leading to polioencephalomalacia (PEM).
- 7,000 mg/L: Can result in death.
Water sources that collect runoff from manure are prone to bacterial contamination. E. coli, a common bacterium in water troughs, can survive for up to a year in water. Shallow wells, ponds, and other surface waters are susceptible to contamination.
E. coli, part of the faecal coliform group, is the best indicator of faecal pollution and the potential presence of pathogens. Mature cattle often have resistance to these contaminants. But, introducing an uncommon pathogen can quickly spread through the herd, causing severe diseases.
Blue-green algae, or cyanobacteria, are common in warm, nutrient-rich water (e.g. from manure and fertilisers). These algae produce toxins that can cause sudden death (neurotoxins) or death within hours or days (hepatotoxins). Preventing algal blooms involves limiting nutrient runoff into water sources and aerating water to reduce bloom formation.
How to Achieve Quality Water for Livestock
- Apply nutrients to fields only when necessary (as determined by soil tests).
- Use groundwater instead of surface water.
- If using surface water, introduce a grassed watershed or buffer to catch pollutants.
- Limit livestock access to ponds or streams using designated crossings or fencing.
- Provide fresh water via pumps or troughs rather than allowing direct access to a water body.
- Regularly test the quality of water for livestock.
Regular water testing is crucial for your livestock. Bacterial water analysis can detect harmful microorganisms to prevent disease spread. Chemical water analysis identifies mineral levels to make sure your animals aren’t at risk of deficiencies and toxicities. Drinking water for livestock should be tested annually and whenever issues are suspected.
Southern Scientific Services has accredited water testing facilities to help! With our help, farmers can ensure their livestock have access to clean, high-quality water, supporting optimal health and productivity.
