When things go wrong on a dairy farm, they usually go wrong in the size of a milk vat – antibiotics in the milk, the milk too warm at pickup or the wash water going in.

Farm insurer FMG says on its website it gets more than 900 claims a year for milk spoilage and contamination.

At the peak of the season it says, that’s five claims a day.

One third is from antibiotic milk in the vat, and another chunk is from plant failure including power cuts.

Another sizeable percentage is from farmers forgetting to turn the chiller on before milking.

And then there is colostrum contamination, birds and other vermin causing problems.

So things do go wrong, either with plant or because tired people forget to do what they should. But it’s the next decision that really matters.

Of course, the easiest way to avoid having to dump milk is to make sure it is always the best product possible.

If you suspect your milk is contaminated act straight away – before the tanker arrives.

Milk companies screen all tanker loads of milk before processing. If a tanker load is found to have an inhibitory substance in it then all of the samples taken on the farms that tanker has collected from are tested.

If your sample is the one with the inhibitory substance in it, then you may have to pay for the whole tanker of milk.

So it’s best not to cross fingers and toes and hope the milker just thought they made a mistake. You have to make sure.

Put a vat lock on your vat first so the tanker can’t pick up the milk and then ring your milk company and tell them what happened, or what you think may have happened. They may advise you to have the milk tested to see if the milk is contaminated and at what level.

If the milk is found to contain an inhibitory substance you may have to dispose of it yourself onfarm.

There are several ways of doing this but the big thing is not to let any of it reach a waterway or enter the groundwater.

Milk is many times worse than dairy effluent and will kill aquatic life as the bacteria breaking it down will consume all oxygen available in the water. Oxygen levels will then become too low to sustain insects, fish and plants.

The easiest way to dispose of milk is to feed it either fresh to calves or pigs or soured and stored using adding citric acid or acetic acid. Yoghurt starters can also be used.

However, be careful if the milk contains antibiotics – as this cannot be fed to certain classes of stock.

You can also dispose of it by putting it through your effluent irrigator on the same land you spray the effluent.

Dilute it first with at least the same amount of water.

The more water you use, and the greater the area you apply it to, the less chance of pasture damage.

Odour can also be a problem so don’t irrigate it near dwellings, public roads and walkways. Check which way the wind is blowing before you start.

Alternatively, the milk can go into your effluent pond but it’s not ideal as mixed with effluent it can cause odour problems and create lethal and explosive gases.

The bacteria in your pond which decompose organic matter may also be affected and it could take months for them to recover.

Digging a hole above the water table and disposing of it there is another possibility. DairyNZ, your milk company and regional council can offer further advice.

Of course, the easiest way to avoid having to dump milk is to make sure it is always the best product possible.

Put systems in place so that the chiller and agitator are always turned on when the milk goes in the vat. Put signs up where you can see them to remind you and your milking staff.

There are many different types of signs to buy but sometimes handmade ones work the best. Put them in the dairy where you and your staff will see them when they are needed.

Have plans for when there is an unexpected power cut so everyone knows what to do. Know where you can get a generator and alternative water supplies if they are affected too.

Make sure there are people you can call during milking if things don’t work – your power company, your electrician and your pump specialist. Have the phone numbers on the wall in the milk room.

Have a maintenance plan so pumps keep pumping and chillers keep chilling.

Keep an eye on milk temperatures as summer approaches and be ready for hot days when volumes are still high and there is extra stress on vat chillers.

Milking earlier in the morning when the air is cooler can help and make sure the milk is entering the vat at the right temperature. It could be your primary cooler that needs some TLC.

Milk vat insulation is another option.

To keep wash water out of the vat have your wash procedures displayed in the shed in an easy-to-follow list. Include a reminder to check the taps are in the right position before putting the wash through.

Keep colostrum cows and cows being treated with antibiotics in separate mobs to the main herd and milk them last.

Colostrum cows must go through eight milkings before the milk can go in the vat – make sure you have procedures so everyone milking knows when individual cows can be added to the herd.

Identifying antibiotic cows is usually done with red spray paint on udders and red tape tied around the back legs. Make sure your staff know to watch out for it so any cows that have jumped fences to get back into the main herd are not milked into the vat.

FMG says almost all of the claims for contaminated milk occur from October to Christmas – when calving is winding down and owners and managers take a break from milking and relief staff take over.

Human error, caused by tiredness and systems that are not easy to follow, or have not been explained to new staff, are the main reasons for things going wrong.

So make sure everyone has time off and all of your staff are well trained and know how to operate the chillers and the wash, and what to do with the milk from cows having antibiotic treatments.

And never rely on crossing fingers.