Herds' hard road costs farmers dear

Cows with bad feet are costing dairy farmers thousands of dollars a year.

Up to 40 per cent of cows in some regions have been affected by lameness this season, a figure vets describe as "phenomenal".

Veterinarian Craig Tanner said his own practice based at Awapuni Veterinary had treated 1200 lame cows in the Manawatu between October and March.

That is on top of cows treated by farmers, or left untreated. Veterinarians have reported "gallons" of penicillin being sold to treat lameness.

Mr Tanner said lameness was the third most important animal health disease vets dealt with, behind mastitis and fertility problems.

The average cost for farmers was about $250 for each lameness incident, said another Awapuni vet, Jos Vermunt.

He said the risk factors varied throughout the world, but in New Zealand the main factors were thought to be dairy shed design, tracks and herd management.

Track condition and the patience of the person moving the herd were strongly linked. Mr Vermunt said a guideline for moving cows should be about 2.7km an hour.

He recommended not using a dog or motorbike and keeping herds of older and younger cows separate to prevent bullying.

High rainfall and sodden ground also contributed to lameness, because the moisture softened the hoof. Moisture also made concrete abrasive and it washed soft dirt or sand off tracks, exposing rough stones.

Nutrition could also be related to lameness - ruminal acidosis can be caused by feed that is high in carbohydrates, such as the maize silage that is increasingly popular with farmers. Feeds containing high levels of protein could also affect lameness.

Trace minerals are essential for the growth of good quality "claws", with zinc and copper being the "popular players".



Mr Vermunt said any feed changes should be made slowly - with a transition of up to three weeks before calving - and farmers should never feed a cow more than 4kg of concentrate (grain or maize silage) at a time.

Farmers could also lower the risk of lameness by selecting sires that had offspring with shorter and steeper claws, in addition to high milk yields.

The risk of a cow developing lameness also increased if they had already suffered from it, he said. It was important for farmers to keep good records of the cows treated, the treatment given and the type of lameness.

Maintenance of the milking shed and cow tracks should be carried out annually, but it was usually a low priority for farmers.

Herds were growing, there was increased use of feed concentrates without necessary precaution, and a lack of stockmanship and awareness in farmers and vets.

Mr Vermunt recommended farmers be ruthless with culling lame cows, especially those with irreparable lesions.

Asked whether there was an ideal breed for New Zealand conditions, Mr Vermunt said herds with pigmented horn were less prone to lameness.

"The friesian/jersey cross was the right cow for us."

He also recommended cowslips that were good for removing pain and helped the recovery process, but said farmers needed to know how to put them on and for which lesions they should be used.

- NZPA