New Zealand's largest family owned dairy business, Crafar Farms, has been put into receivership, Korda Mentha said in a statement.

Receivers were getting mud on their gumboots yesterday as they came to grips with problems of Crafar Farms.

Federated Farmers Dairy chair Lachlan McKenzie responds to recent controversy over the mistreatment of animals on a NZ dairy farm.

Inspectors have begun urgent checks on the welfare of livestock at farms owned by the Crafar family, amid concerns that publicity over alleged cruelty could harm New Zealand's reputation.

Agriculture Minister David Carter says 'dirty dairy farmer' Allan Crafar could do huge damage to New Zealand's reputation.

Fonterra says it won't hesitate to take action, "including refusal to collect milk" if deliberate animal mistreatment is proven.

New Zealand's biggest privately held dairying operation allowed dozens of calves to slowly dehydrate to death.

Test results due back today may point scientists towards the cause of the mystery illness or illnesses affecting dogs and wildlife in the Hauraki Gulf.