Water is the single most important nutrient consumed by livestock. The rumen needs water to function, as it is essentially a brewing vat that ferments feed to extract nutrients.

If an animal cannot drink enough water to meet its requirements, feed intake is reduced. This is because stock stop eating and wait for an opportunity to drink, before resuming grazing. Apart from being stressful, reduced feed intake corresponds to decreased production of milk and/or growth.

Depending on the stage of lactation, growth, or pregnancy, water requirements change. Animals get their water from drinking and eating (the water within feed).

Factors that increase water requirements are:

• Fast growth.
• Milk production: Milk is 86 to 87 percent of water and this places a large demand on the lactating animal.
• A higher dry matter diet, due to, for example, high dry matter supplements or summer pasture.
• Pregnancy.
• Hotter temperatures and/or high humidity.
• Level of activity.
• Consumption of salt, sodium bicarbonate and protein which stimulate the drive to drink.

For milking cows, LIC reported that milk production can decrease by 10 to 20 percent if the amount of water on offer does not meet demand.¹ Lactating dairy cows grazing pasture typically require more than 100 L per day in early lactation and beef cattle more than 65 L per day in the same stage of lactation. Increased milk volumes can drive this requirement even higher, as can higher dry matter feeds like PKE or summer pasture, and increased heat and humidity.

It is an animal welfare requirement that animals always have free access to fresh, clean water to meet their daily requirements. Just because a water trough has not run empty, does not mean all animals have had an equal chance to drink.

To help meet an animal’s requirements:

• Ensure there are enough troughs per paddock, with a system supplying enough water to each trough according to the mob size.
• Placing troughs along the race and entry/exit of the dairy shed helps give more submissive cows a chance to drink.
• Multiple troughs on feed pads.
• Cleaning troughs routinely is good practice and restricting access to waterways that may carry contaminants is preferable.

Designing an appropriate water system is more complex than just adding more troughs. The two most critical factors are pump capacity and water pipe size. Reduce water shortages through early leak detection systems, water tank monitoring and strategic positioning of tanks.

If you feel your stock may not be receiving enough clean, fresh water, visit your local PGG Wrightson store team who can assist you with stock water design solutions and componentry.

1 Sutton, D. (2020, November 25). Preserving and protecting water on farm this summer. LIC https://www.lic.co.nz/news/preserving-and-protecting-water-farm-summer/.