6 November 1998

First, get chemical rates right…

By Peter Grimshaw

CUTTING costs of dairy chemicals is more difficult than getting the best results from them once in use. While many milk producers lay much score by purchase price, they are less aware of the cost of using products carelessly.

Ian Ohnstad, ADAS milking technology consultant, says ensuring the correct amount of chemical is being used should be the first priority.

"Over-use is widespread. Follow manufacturers instructions, because if you dont you are potentially pouring money down the drain," he warns.

He still sees dairies where the milker has increased the dose of cleaning chemicals to solve a hygiene problem. It is still part of popular mythology that more means better, he says.

The truth is that increasing concentration does nothing for a products sanitising properties – but it reduces the life of rubber components.

Often, those responsible for sanitising milking equipment, after milking have only a vague idea of the water volume recirculating. This makes it impossible to accurately mix the correct chemical dose.

Another common fault is to use correctly mixed solution to carry out the warm-up rinse, running away useful chemical before the target temperature is reached. "That chemical goes straight down the drain," he says.

Most plants take 4-6 litres of hot water for each milking point before reaching circulation temperature.

Start with plain warm water, then add chemical to the recirculation trough when a discharge temperature of 55C (131F) is reached. "When you add chemical earlier, you could be using 30% more chemical than needed," he estimates.

Teat dips also offer room for more effective and efficient use on-farm.

Mr Ohnstad explains that teat disinfectants have a dual role. One is to disinfect the teat surface and provide a barrier to invasion of the teat canal. The other, is to condition teat skin – keeping it soft and supple and protecting it from chapping and roughness which allows bacterial colonisation.

The bactericidal activity of most teat disinfection products is good, he says. However, the protection afforded to teat condition depends on emollient concentration.

"High quality, ready-to-use products may contain up to 10% emollient. Other products used as concentrates for dilution may contain the same amount in the concentrate, and if mixed at, say four to one, youll end up with 2.5% emollient."

Mr Ohnstad says teat conditioning capacity of dips is more important when extending the grazing season. "Be aware that requirement for emollient changes as the season changes.

"This year, animals have been outside in some pretty unpleasant weather, so sticking with a cheap teat dip may be a false economy."

One way to reinforce the emollient effect of a dip is to add glycerine from a local chemist. Care is needed, however, because such admixture can reduce bactericidal qualities of the dip.

"The organic content of glycerine can neutralise disinfectant. If you add too much, you reduce disinfectant efficacy."

Care must also be taken to ensure that a home-mixed dip is shaken after standing, because unlike factory homogenised products, the added glycerine will settle out.

He prefers dips to sprays. Although the latter ensure a completely uncontaminated application of active compound, spraying can be more hit-and-miss than dipping, and it may use more product. Submersing the teat applies positive pressure, ensuring that active agents get into the teat orifice and cover the whole teat barrel.

Over-use of dairy chemicals is widespread, wasting money,

warns ADASs Ian Ohnstad.

From teat dips to cleaning chemicals, better use could be made of most dairy chemicals, allowing cost-cutting without compromising on price.