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Milk disposal on your farm may become necessary after an adverse event. This page covers guidelines for various disposal methods, including applying milk directly to the land or discharging into effluent ponds. When applying to land, dilute the milk and ensure it doesn't reach waterways. Care should be taken to prevent odour issues and pasture damage. Feeding surplus milk to livestock is another option, but the milk must be fit for purpose, and you must follow specific guidelines to prevent digestive disorders in the animals. If you need assistance with milk disposal, contact your dairy company or regional council.
You may be in a position where your milk may need to be disposed of on your farm. Find out about your options below.
After an adverse event, there may be certain restrictions or changes to milk disposal rules. If you need to dispose of milk after an adverse event, contact your dairy company for advice.
Milk can be applied directly to land. The following guidelines should be followed (similar guidelines apply to the disposing of whey or any other liquid dairy products):
Do not apply milk to:
Milk can be control-fed into a pond system, though a land application is preferable to discharging to a waterway.
Odour problems may occur 5 days after milk has entered the system. Be aware that a mixture of milk and effluent can give off lethal or explosive gases. Do not mix them in confined spaces or buildings, or enter any enclosed effluent storage facility.
Properly designed 2-pond systems (adequate size and correct construction) can cope with milk from four consecutive milkings. After this, another option should be used as additional milk will cause a rapid deterioration in the quality of the discharge.
Ideally, the treated effluent from the ponds should be spread onto land as soon as possible, (e.g. using a contractor) to reduce any impact on the receiving waterway.
Here are the following recommended disposal options:
Note: in Northland, your regional council does not recommend you discharge any milk into your oxidation ponds. They would prefer that where possible you apply to land and if this is not possible you dig an appropriate ditch as described above.
If you need help, contact your dairy company, the regional council or DairyNZ for advice.
If at all possible, feed the surplus milk to livestock. Nutritionally, milk is low in dry matter content (i.e. approximately 13%), and is high in energy (i.e. 20 to 23 MJME per kg of DM), protein and fat.
Dairy cows can be fed up to 10 litres a day. The milk could be fed via water troughs or spread on silage if it is suitably contained. The milk must be fit for purpose (i.e. must not contain antibiotics).
Calves can consume between 8 and 12 litres of whole milk per day before weaning. After weaning, up to 4 litres per day can replace 1 kg of concentrate feed. However, the use of milk should be limited to minimise the risk of digestive disorders. It should be introduced to the calves slowly, and be supplemented with digestible fibre-based feed to encourage proper rumen function. Ad-lib access to hay is advisable while milk is being fed.
Milk may also be transported to neighbours with piggeries or commercial calf rearers.
Milk is best fed consistently fresh or consistently sour to dairying stock. Souring in a storage facility can be prevented for up to one week by adding citric acid or acetic acid. Commercial yoghurt starters can also be used to make a coagulated yoghurt from the milk, and the yoghurt fed to stock. If in any doubt about the feeding of milk to stock, consult a veterinarian.