Dairy NZ

Mastitis is an inflammation of the udder.  It is usually caused by bacteria that enter through the teat end and infect the udder. The terms "mastitis" and "infection" are often used interchangeably since preventing mastitis is about preventing a bacterial infection Mastitis is defined by changes in appearance of the udder, cow and/or milk. Clinical mastitis - shows changes that are VISIBLE to the naked eye Subclinical mastitis - shows changes that ARE NOT visible. New Zealand farmers and advisors now have access to the highly comprehensive technical resources of the Australian Countdown programme.

Healthy udders should be the main goal for all herds

Mastitis is a costly disease.  Each case of clinical mastitis is estimated to cost approximately $200 per case in cost of drugs and discarded milk, labour and short term production losses. Subclinical cases cost money in terms of long term milk production losses. 

Total costs for an average herd are estimated to be $54,500 per year or $180/cow.  This is for a herd that has: 

• 300 mixed age cows
• A bulk milk SCC averaging 200,000/ml
• Treats 45 cases per year (15 cases/100 cows per year)
• Payout of $6.00 per kg milksolids.

 This means:

1. Preventing mastitis through:
   1. Milking cows in a hygienic way
   2. Disinfecting teats after every milking
   3. Maintaining the milking machine so that teats remain healthy and cows are milked out well
   4. Preventing infections in the dry period and after calving through appropriate use of long-acting antibiotics at dry off
   5. Preventing heifer mastitis using an appropriate strategy for your herd
2. Finding new clinical cases and monitoring subclinical cases.
3. Treating infections effectively and cost-efficiently.  This may mean:
   1. treating clinical cases with antibiotics,
   2. treating subclinical cases in the dry period with long-acting antibiotics
   3. culling cows with chronic mastitis