Although consumed in large quantities and a vital nutrient for all classes of livestock, water quality and its potential impact on performance is a low priority on most livestock units.

And while feed ingredients are analysed and assessed on a regular basis, water is seen as just water, yet it's quality can vary significantly with potential consequences on performance.

According to Lorna Shaw, technical support co-ordinator with Trouw Nutrition GB, dairy cows can consume at least 60 litres per day and sows around 25 litres a day, therefore, it is advisable for all producers to regularly check water quality, especially if it is sourced from a borehole.

She said there are two main areas where water quality will vary and which can have an impact on livestock performance. The first is the mineral content which can influence overall mineral intake for the animal. The second is the microbiological profile and the degree of contamination.

While the mineral content is entirely a factor of the water as extracted or delivered to the farm, the microbiology can also be influenced by the contamination of equipment on farm such as drinking lines and water troughs.

Miss Shaw says young calves and nursing piglets are the most vulnerable to high nitrate levels, particularly those being hand reared or fed supplementary feeds during nursing due to potential for nitrate toxicity if high levels are consumed over a short period of time. High levels of microbial contamination in water can impact performance of pigs and poultry resulting in poor faecal consistency, increased feed conversion ratio, reduced average daily gain and also a reduced feed intake.

Trouw Nutrition WaterWatch assesses the microbiological and mineral composition of borehole and mains water throughout the UK, providing regional comparisons.

“The latest results show that nitrate levels are elevated on average in Scottish borehole water sources with a majority of samples showing a nitrate level of 100 mg/l, which although elevated is not a level to cause concern for ruminant livestock provided the ration is not also high in nitrates.

The average water mineral levels demonstrate that concentrations of calcium and magnesium are lower in Scottish water compared to the rest of the UK, meaning the water type in Scotland is softer compared to the rest of the country. Softer water will reduce the possibility of limescale build up in the lines which is a common problem with hard water.

“In general the mineral requirement of the animal will be provided by the diet so in most units water mineral content should not be a concern unless levels are significantly increased. For example, high levels of sulphur and iron in borehole water can pose risks of copper antagonism.”

She says microbial analysis from samples submitted from pig and poultry farms results show that elevated levels of microbial contamination including Enterobacteria, yeasts and moulds can be present particularly in the drinker line which can upset the balance of the gut impacting performance.

“There are a number of signs that can indicate poor water quality on farms, particularly related to microbiological profile,” said Miss Shaw. “Reduced water flow and the presence of biofilm in drinking lines and water troughs can suggest microbial water quality is an issue.

“Reduced water intake or animals turning away water are a sure sign of a problem which can reduce feed intake having a negative impact on performance.”

She emphasises that no farm is average and recommends taking action to improve water quality, starting by having borehole water analysed regularly to monitor mineral levels closely as these may vary with season. She says best practice will be to have samples tested at least every six months.

“Where high nitrate levels in borehole water are very high, the addition of a filtration system can be considered to reduce nitrate concentration in the water. Take steps to reduce potential run off and ensure boreholes are not situated on land that receives regular manure or fertiliser applications.

“Regarding microbiological quality, microbes living in the water lines contributing to biofilm build up blocking water lines and contaminating water. Consider water treatment to combat biofilm build up in the water line and improve water quality. Water treatment can also be beneficial to support pig and poultry performance.

“Monitoring water quality and taking action to rectify any problems should be seen as a routine management task on all livestock units,” she advises.