22 December 2000

Vets report mastitis rise as producers curb costs

By Hannah Velten

INCREASING cow numbers in an effort to dilute overheads, humid weather and cost cutting measures are already leading to increased cases of clinical mastitis this winter and action is needed to minimise risks.

Although NMR figures show somatic cell counts have fallen this year since September – from 181,460/ml to 170,000/ml in November – figures show an increase in cell counts compared with last Novembers 161,470/ml.

Cell counts are expected to rise further over winter, says ADAS mastitis specialist Ian Ohnstad. "More clinical cases being seen by vets will be reflected in increased cell counts. In addition, because many herds are unlikely to meet quota, high cell count cows are being kept rather than culled."

Clinical cases of environmental mastitis – mainly caused by E coli and Strep uberis bacteria – are particularly on the rise, warns independent veterinary consultant Tony Andrews.

"The unseasonably warm and wet conditions are ideal for mastitis bugs and allow them to survive in the environment."

Poor quality bedding helps spread infection and producers must be obsessive in their attention to hygiene this winter, advises Mr Ohnstad.

"Clean, dry bedding is essential and because of poor quality straw this year producers need to assess bedding stocks, take a view on how much is needed to last until turnout and then decide how much poor straw can be thrown away."

When bedding is of poor quality, Mr Ohnstad suggests using a pre-milking teat disinfectant or, in severe cases, the use of an E coli vaccine under vet guidance.

"Alternatively, it is possible to use disinfectant or antiseptic products on wet bedding to help reduce carry over and retention of infection," advises Dr Andrews.

Any dry straw should be reserved for separately housed cows in their first month of lactation, who are most susceptible to infection as their defence mechanism are reduced around calving.

Scraping slurry from cubicles two or three times a day and clearing out covered yards every four to five weeks is also an essential part of routine hygiene, adds Mr Ohnstad.

Overcrowding in housing will cause further infection and with profits down, many producers are buying in extra cows to dilute overhead costs, says Peter Edmondson of Shepton Veterinary Group, Somerset.

"Some producers are pushing up cow numbers by 10-20% and putting them into housing which cannot accommodate them."

Cattle stocking density should never be exceeded in buildings. Mr Ohnstad stresses that every cow should have her own cubicle and in covered yards, 6.5sq m (70sq ft) a cow is needed for bedded area and 2.5sq m (27sq ft) a cow of loafing area.

Dr Andrews adds that buying in extra cattle and putting pressure on the system may also lead to costs associated with disease, infertility and drops in yield, reducing profit in the long term.

Producers who feel forced to cut variable costs could be increasing mastitis infection, adds Mr Edmondson.

"Changing to a cheaper brand of teat dip or skipping routine maintenance on the milking machine may mean short-term gain, but may cost dearly in the long run when mastitis strikes."

Mr Ohnstad advises using a teat dip licensed by the Veterinary Medicines Directive to guarantee efficacy and to service milking equipment regularly.

"Poor pulsation, vacuum levels and vacuum regulation performance will cause teat damage, mastitis and reduced milking performance."

Dry cow therapy is another cost producers may be tempted to cut, but Mr Ohnstad argues that they cannot afford to disregard treatment.

"Dry cow therapy protects against new mastitis infection and clears up lingering infections from the previous lactation." &#42

ENVIRONMENTAL MASTITIS

&#8226 Attention to hygiene vital.

&#8226 Ensure clean, dry bedding.

&#8226 Stocking density important.