How The Dispensers Work

All PETA Dispensers are used in animal water troughs.

The treatment material, such as bloat control material, zinc or mineral supplements, is added into a container (a standard jerry can or flagon). Trough water is then added too and the dispenser is inserted.  The lid (which is part of the dispenser) is screwed closed.

The dispenser is then placed head-down in the trough and dispenses the treatment material continuously over its designed time frame. Simply by drinking water from the drinking trough, your livestock receive their required dose of treatment.

It sounds simple enough, but there is actually a lot of robust science behind the precise design of each of the dispensers.  This scientific and patented design is what makes it all possible.

The Important Per-Animal-Per-Day Principle

One of the most important principles when treating animals through drinking water is that water should always be treated on a per-animal-per-day basis, and not a per-litre basis.

The reason for this is that daily water intakes can vary dramatically. For example, the daily water intakes of cows can vary from 10 litres to as much as 70 litres per cow, depending on the temperature of the day, the dry-matter content of the feed, and other factors.

A water treatment system must compensate for these large fluctuations. Treating water on a per-litre basis would mean over-dosing on high intake days and under-dosing on low intake days.  Instead, with the clever engineering of the patented PETA Dispensers, the right amount of dosage per animal is dispensed each day, regardless of fluctuations in water intake.

Why Directly Dosing a Trough Fails

Knowing that dosage should be measured on a per-animal-per-day basis, you might wonder if the treatment solution could be added directly to the drinking trough. This however fails miserably as a treatment solution, because the treatment concentration levels in the trough varies dramatically over the drinking period.  The concentration level starts off very high decreases exponentially as the trough keeps refilling.

This means that animals who drink first get overdosed due to the high concentration, and animals who drink at the end get severely under-dosed due to the very weak concentration remaining.

Scientifically Designed to Match Drinking Patterns

The scientific research at world-renowned Ruakura Agricultural Research Centre in Waikato, New Zealand, found that if the treatment material was dispensed at a rate that matched the daily drinking pattern, and the ball-cock continued to fill the trough to normal levels, an almost uniform concentration level could be maintained in the trough.  As can be seen in the graph.

It is on this research that PETA Dispensers are grounded.

This means that no matter whether an animal drinks mainly at the start, middle or end of the drinking period, they will be drinking the same concentration as all other animals in the herd that day.

What about on low intake or high intake days?

The amazing thing about this research and PETA Dispensers is that it works even on low intake or high intake days.

On a low intake day, when the herd is not drinking much, the concentration level in the trough increases, and then remains at a fairly uniform concentration for the remainder of the drinking period.  (As seen in the graph).  Because the dosage quantity is planned on a per-animal-per-day basis, and the full treatment for the herd is still dispensed over the drinking period, your animals receive their correct dosage for the day from only drinking a little of the higher concentration.

On high intake days the opposite occurs – the concentration drops to a lower uniform level. The full treatment for your herd is dispensed over the drinking period, and your animals receive their correct dosage for the day while drinking a lot of the lower concentration.

(Note that the graphs show the trough starting with an initial low level of concentration, which is from the residue of the previous time the trough was treated.)

Matching Milking Cows Drinking Pattern for Bloat Treatment

The graphs above showed a herd’s drinking pattern over 24 hours. This works fine for treating facial eczema with zinc or when applying magnesium, trace elements and salts. It also works for controlling bloat in dry stock.

However, milking cows have a distinct drinking pattern, and bloat can attack milking cows incredibly quickly.  So to control bloat in milking cows we use a pair of 12-hour bloat dispensers (a “day” dispenser and a “night” dispenser), which closely match the unique drinking pattern.

The day dispenser gives a 6-8 hour outflow period, covering the morning drinking period.  The night dispenser has a 3-4 hour outflow period covering the much shorter evening drinking period.

This means that milking cows receive their needed dose in the timeframe needed to provide stress-free bloat control.

How do the mechanics of the dispenser work?

PETA Dispensers work through a clever use of the principles of hydraulics. The treatment solution in the container is denser than water and so gravitates downward and out through the outflow regulator into the trough.

The treatment material in the container is slowly replaced by the less dense water from the trough, via the inflow regulator nozzle giving a syphoning action inside the container.

The airspace in the container keeps it afloat in the trough.

The outflow rate has been matched to the drinking curve of animals throughout the day. This maintains a near constant concentration in the trough throughout the drinking period, for either 12 hours, 24 hours or 48 hours, depending on the model of dispenser.

PETA offer three different types of dispenser – bloat, zinc and multi-purpose – due to the large differences in density between bloat treatment, zinc and mineral supplements. The principle of how the dispensers work is the same, but the outflow rates have been fine-tuned for the density of the treatment material, to ensure correct dosage rates.  (For example, you cannot use a Multi-Purpose dispenser to dispense zinc on its own as it will dispense too quickly and overdose the livestock. Use the specific Zinc Dispenser for controlling facial eczema.)

An important feature of the PETA dispensers is that they have no moving parts, and virtually nothing to go wrong. They will last for years with no maintenance apart from an occasional clean.

Developed and manufactured in New Zealand

PETA Dispensers started manufacturing dispensers in 1976 based on scientific water studies at world-renowned Ruakura Research Centre, in Waikato, New Zealand. The dispensers continue to be developed, manufactured and serviced in Hamilton, New Zealand. You can read about the history of PETA Dispensers here.  


Each dispenser is made from high quality materials and guaranteed against all defects in construction and materials for 12 months from the purchase date. Please complete the warranty registration form within two months of purchase. For warranty needs contact us.

Available in New Zealand, Australia, UK, Japan and more.