Written by Dr. Andrew McKay
Water is an essential nutrient for livestock production, required for so many physiological functions such as absorption of nutrients, temperature regulation, tissue growth and waste excretion. Despite its importance in livestock production, water quality is often overlooked and it is no surprise that can be referred to as ‘the forgotten nutrient’.
The water requirements vary depending on environmental conditions and the life stage of the animal. Ad libitum access to clean water is essential to maintain feed intake. The more an animal drinks, the more it will eat. Even minor dehydration can result in reduced feed intake, lower daily weight gain, poorer feed conversion, reduced milk production and lower weaning weights.
The quality of water used in livestock production varies greatly depending on the water source. Water sources include civil (town) water, surface (river, dam) and underground (bore). Water can act as a vector to introduce pathogens into the animal, increasing the risk of disease.
Water quality should be assessed and monitored regularly by livestock producers to optimize animal welfare and performance.
Water contamination can be assessed as follows:
- Gross contamination: Physical appearance, odour, cloudiness or turbidity
- Chemical and mineral contamination: calcium, magnesium, sulphate, iron, manganese
- Microbiological contamination: bacterial, fungal or parasitic agents
Even seemingly “clean” water, supplied from town water sources, can contain pathogens. Town water is typically delivered on farm vi holding tanks, where water may stagnate and become contaminated, particularly in warm weather. Water can also become contaminated by the build-up of biofilm in farm waterlines.
Biofilm is a slimy layer of bacteria and other microorganisms that adhere to the inside surface of waterlines. As water flows through the waterlines parts of the biofilm can break off and contaminate the water.
Regardless of its source, farm water should therefore be tested regularly, at the start and the end of drinking lines, to monitor water quality and the impact of biofilm. Poor water quality will have a detrimental effect on animal welfare and productivity. In order to optimize animal performance, livestock producers should therefore consider strategies for removal of biofilm and ongoing treatment of drinking water.
Clean water plays an important part in Biosecurity
Contaminated water supplies have been implicated in the introduction and persistence of endemic pathogens such as Escherichia coli (E. coli), Salmonella spp., Campylobacter spp., infectious bursal disease virus (IBDV) or egg drop syndrome (EDS), and in the introduction of emergency animal diseases (EADs) such as virulent Newcastle disease virus (vNDV) or avian influenza (AI).
These pathogens can be introduced via the drinking water, cooling pads, overhead sprayers and wash down water. All water entering the farm can pose a risk in the introduction of pathogens.
It is therefore beneficial to understand the quality of the water entering the farm and treat it accordingly if the quality is not at an acceptable standard.