28 February 1997

Research puts lameness on much firmer footing

In the second of our series taking research into practice, we asked the vet running MAFFs cattle lameness studies to help a Staffs milk producer. Jessica Buss joined them on farm

LOW-COST alterations to winter housing could reduce lameness incidence by 10% next year at Stephen Brandons New Buildings Farm, Hopton.

"Investments to reduce lameness must be justified on either cost or welfare grounds based on the likely effect of any change on lameness incidence," said Richard Murray, who co-ordinated Liverpool vet schools research into dairy cattle lameness on 37 farms.

Mr Brandons 160-cow 7400-litre herd – not in the trial – has a lameness incidence just below average with 60-65 new cases for every 100 cows a year.

Poor foot hygiene allowing cows to stand in too much slurry which softens the horn can be a major cause of lameness, causing dermatitis, sore heels and underrun soles. But on this farm poor hygiene was only responsible for 7-15% of lameness. Cows feet stay clean because the large yard provides plenty of loafing area.

"It will be uneconomic to slat passageways or install automatic scrapers to improve foot hygiene on the farm because it would have little impact on the herds lameness," advised Dr Murray.

Instead of slurry being a major lameness cause at New Buildings Farm, 39-46% of cases here are related to overloading of the outer claw (OOC) – resulting in white line lesions, ulcers and bruising.

"Overloading occurs when the horn grows faster than it wears, in response to the environment, making it more susceptible to bruising, ulcers and damage," he said. "The two risk factors identified for OOC in our studies were cows not lying down for long enough, and the concrete surfaces the cows walk on."

At the farm all cubicles measure 1.2m x 2.2m (4ft x 7ft3in) and have Newton Rigg divisions with the top rail set at 0.93m (3ft1in). Although not ideal, these divisions at 1.2m (4ft) cause no hock sores so do not need altering.

But Mr Brandon had noticed that cows disliked cubicles in the double rows, although they could put their heads forward making it easier for them to get up. The only difference was that these cubicles have a head rail to prevent cows standing too far forward.

Dr Murray advised removing the headrail and putting a new rail at 1.13m (3ft9in) between the two rows of cubicles. "To stop cows standing too far forward the lying and standing area must be 5ft10in," said Dr Murray. He suggested replacing the lower front rail with a fillet of concrete sloping up to a height of 45cm (18in).

However, modifying cubicles is complicated. His advice was to alter 40 of the 150 cubicles to check the change is acceptable before adapting them all. Cubicles have deep straw bedding with 3kg of straw added to each three times a week. When cubicles are this well bedded there is little benefit in fitting mats, concluded Dr Murray.

The Liverpool studies also found floor surfaces were often responsible for overloading the outer claw. The shear forces on the sole of a cow turning corners on a smooth surface stimulates growth more than grooved concrete when there is less movement of the sole.

Mr Brandon has grooved the concrete on parts of the yard already. But cubicle floors and some of the feed yard are smooth. Risks of bruising will be lower if these smooth surfaces were grooved, said Dr Murray. The grooving machine can be hired at relatively low cost.

The feed yard also has some deteriorating concrete that is over 25 years old and contains rough hard stones that can bruise cows feet. In the long term the worn area needed replacing, he said.

Nutrition also affects lameness incidence. Mr Brandon usually makes high dry matter silage and with wetter silage. This encourages cows to cud reducing acute laminitis risks, said Dr Murray.

Breeding cows less prone to lameness may also reduce cases, he said. He advised against breeding cows that needed extra trimming.n

Grooved concrete is better for cows feet than smooth or worn concrete.

Cubicle divisions cause no damage to cows hocks, says Richard Murray.


SHORT-TERM PLAN


&#8226 Alter one bank of cubicles to increase lying time.

&#8226 Reduce hoof shear forces by grooving concrete.

&#8226 Continue to make dry silage.


LONG-TERM PLAN


&#8226 Use data to improve breeding decisions.

&#8226 Reduce bruising by replacing worn concrete.

&#8226 Monitor progress using data.