12 April 2002

Recoup price losses by cell count cutting

By Jessica Buss

MANY milk producers, hard hit by this months price cuts, could gain 0.5p/litre or more by reducing cell counts.

NMR figures show many producers could be missing out on milk buyers premium cell count bands as only 60% of recorded herd are achieving a bulk cell count of below 200,000/ml (see table). The number of producers in that band has also reduced in the past two years.

Cell count bands do vary according to milk buyer with some offering 0.3p for cell counts below 150,000 and 0.3p for 150,000-200,000, says Ian Ohnstad, ADAS milking technology specialist. Others can offer 0.5 or 0.6p/litre more for milk below 200,000 or 250,000.

Although some producers may find it is not worth investing to lower cell counts, most have little clue what it is costing, he adds. A 0.5p/litre bonus on a 100-cow, 6000-litre herd is worth £3000 a year in direct costs.

"But there will also be indirect costs of clinical mastitis cases and cows with sub-clinical infection have depressed milk yields and constituent quality can be reduced."

Often when cell counts run just outside the top cell count band there is no simple answer, says Neil Howie of the Nantwich Vet Group, Cheshire.

"A couple of newly infected clinical mastitis cows in a 100-cow herd can increase cell count by 100,000." High cell count cows can be identified using NMR records, a California milk test or with a new conductivity detection machine. These allow milk to be discarded and infected quarters identified for treatment, he adds.

There is currently the added problem of high cell counts cows, which should have been culled, being kept on due to foot-and-mouth, adds Mr Howie.

Mr Ohnstad adds that many producers are also increasing herd size, so are reluctant to cull persistently infected mastitis cows.

While culling these cows will help, Mr Howie stresses that is still vital to address the problem to avoid other cows taking their place. It is essential to ensure the five-point plan is followed, but there are also new ways to help combat high cell counts.

"There are now antibiotics to treat high cell count cows which can be successful alternatives to culling persistent offenders.

"Herds with increased cell counts should assume its a problem with the milking machine, until it can be ruled out. Check teats for damage and teat end condition as an indicator of the machines performance and settings – such as vacuum level."

But, according to Mr Ohnstad, the milking machine is only at fault in 15-20% of cases. "Often the problem is the milking routine, operator or inadequate accommodation."

It is also easy to assume it is an environmental problem, but bacteriology tests then prove the opposite, he adds. Bacteriology tests on bulk milk samples are now possible at a number of labs to help highlight which bugs are present, says Mr Howie.

"Finding out whether the challenge is Strep uberis from straw yards or Staph aureus from chronically infected cows in the herd helps target control efforts."

Mr Howie also believes more herds are keeping fresh calvers in straw yards, increasing risk of Strep uberis infection, but the barrier type teat dips now available can reduce infections.

When the problem is spread of mastitis during milking, he suggests trying pre-dipping or plunging clusters in a new chemical to kill bacteria. "Pre-dipping will take 20 minutes a milking in a 100-cow herd, but it can reduce E coli and Strep uberis, saving time treating mastitis cases."

"The chemical peroxyacetate which destroys cells on contact is useful for Staph aureus problems. Unlike other chemicals, it kills bacteria instantly and leaves no harmful residues." &#42


2000 2001 2002

Less than

200,000/ml 72% 70% 60%

201 – 250,000/ml 16% 17% 20%

251 – 300,000/ml 7% 8% 11%

301 – 400,000/m 4% 5% 7%

Above 401,000/ml 1% 1% 2%