Mastitis basics

What’s happening: Cows calve and start producing milk and their immune system is under stress. In the first few weeks milk production ramps up and the herd gets into a milking routine.

Common risks:

• Environmental bacteria.
• Newly calved cows and heifers.
• Colostrum cows

Why: Cows and heifers are at increased risk of mastitis around calving due to reduced immunity, udder pressure and leakage, environmental exposure during calving, and physical changes like udder oedema that make it easier for bacteria to enter and establish infection.

Focus on:

• Calving, udder and milking hygiene: clean calving area, clean shed, effective teat spraying.
• Keeping colostrum cows separate – monitor cows closely at every milking.
• Ensuring milk is safe to go into the vat.

Use:

• RMT testing to confirm mastitis and ensure milk is clear before going in the vat.

What’s happening: Peak production passes and the herd stabilises but cows still need monitoring for mastitis through individual and bulk milk somatic cell counts.

Common risks:

• Bacteria spreading during milking.
• Bacteria picked up in dirty, wet areas on farm.
• Poor milking routine.

Why: Cows can still develop mastitis during mid-lactation due to ongoing exposure to environmental and contagious bacteria, particularly if milking hygiene or teat condition declines. Factors such as poor milking practices, damaged teat ends, and undetected subclinical infections can also increase the risk and spread of infection within the herd.

Focus on:

• Consistent milking hygiene.
• Correct cup placement and removal.
• Monitoring SCC trends.
• Checking for clots on the filter sock.