15 September 1995

HIGH CELL COUNT, HIGH COST

Tough new hygiene rules demand super-clean milk with a cell count below 500,000/ml by 1997. Jessica Buss seeks husbandry advice on meeting this target

FINANCIAL penalties for high cell count milk will be costly for the 16% of producers who still fail to achieve levels below 500,000 cells/ml.

The warning comes from Leeds-based ADAS national milking technology specialist, John Baines.

He is conscious that milk hygiene rules preventing milk with a somatic cell count above 500,000/ml being sold for human consumption become effective in 1997. But many milk buyers are already paying a premium for milk with less than 250,000 cells/ml.

He cautions that 12 months of action will be needed before a consistent improvement is seen in problem cell count herds.

High somatic cell counts a lot of mastitis points to poor hygiene and cow management.

"But there is no relationship between cell counts levels and clinical mastitis incidence for they are caused by different pathogens," he says. However, high cell count herds are likely to have a higher mastitis infection rate, for the husbandry which controls cell counts also controls mastitis.

"Low cell counts do not signal poor resistance to mastitis, but that the cows are subject to low bacterial challenge," he says. "But low cell count cows are still at risk from mastitis so effective control measures are needed."

Control of cell counts and mastitis will be achieved when the "five-point plan" is acted upon (see box).

Mr Baines also advises that mastitis risk can be reduced by housing cows in well-ventilated buildings, and keeping cows beds clean and dry. Fresh bedding should be pulled onto the bed every day and beds dusted with lime every few days.

The fresh bedding helps keep teats clean so they require little preparation in the parlour. Dirty teats carry bacteria and are prone to developing sores which can be-come infected with mastitis bugs.

"Washing and drying dirty teats is acceptable when done properly," says Mr Baines. "Pre-dipping teats with disinfectant and drying is also an effective method of cleaning." He advises foremilk is checked for abnormalities including mastitis before the cluster is put on.

Mastitis cases should be treated with antibiotics as advised by a vet. "Cows which have more than three cases in one quarter or five in an udder in a lactation should be culled," he says.

"As for milking equipment, it needs to remove milk quickly and efficiently without over or under milking or causing damage and aggravation to the teat tissue."

Mr Baines recommends claw pieces and wide bore short milk tubes which allow quick flow of milk away from the teat.

He adds that the milking plant can transfer bugs from cow to cow. It is important therefore that the installation can be cleaned properly.

Maintenance of the plant is also essential to ensure vacuum levels and pulsation are correct. This will prevent damage to the cow which increases risk of mastitis.

"After the cluster is removed it is vital to disinfect the whole teat surface, to maintain skin condition and prevent lesions becoming infected," he says. "Teat disinfectant with 10% glycerine is likely to produce the best teat condition."

He also advises that at the end of lactation each cow is treated with dry cow therapy. "Choice of the correct antibiotic and treatment methods should be discussed with a vet," he says.