A New Zealand farmer who allowed hundreds of cattle to become severely emaciated has been ordered to pay $NZ53,000 ($A41,482.41) in costs.

Keith Thomas, from Wellsford north of Auckland, pleaded guilty in March to five charges under the Animal Welfare Act and was sentenced in Warkworth District Court on Wednesday.

As well as the costs, the court made an enforcement order for supervision of his property for two years.

The Ministry of Agriculture and Forestry (MAF) said Thomas had 622 cattle on three adjoining Topuni properties, one of which was assessed by inspectors in 2006 following a complaint by a member of the public.

The property was found to be run down, with no water or pasture for grazing and no supplementary feed, and the cattle were malnourished and having difficulty walking.

When MAF representatives visited the other farms they found more cattle in a poor condition, with evidence of deaths.

Thomas was told to urgently provide feed and water for the animals but didn't comply, forcing authorities to move the cattle and test them.

Veterinary inspections identified chronic under-feeding and found 90 per cent of animals were in an emaciated condition and some showed signs of severe malnutrition. Fifty six of them had to be put down.

The court acknowledged the offending took place at a time when Thomas was "immobilised with despair" due to personal circumstances, but Judge Barbara Morris said the farming community needed to know such conduct was unacceptable.

The $53,000 figure related to costs to others Thomas had created by his treatment of the cattle.

MAF investigations manager Greg Reid said he was surprised a farmer as experienced as Thomas could let the situation get so bad.

"I cannot accept that he didn't realise how serious the situation was and that his cattle had literally been starving to death for weeks," Mr Reid said.