The environment generally increases the risk of mastitis in one, or both, of two ways:

• An increased opportunity for teats to contact environmental sources of bacteria
• The adverse effect of weather and mud on teat skin condition, causing dry, chapped skin which harbours many more bacteria, and can also affect milking performance

Basically anytime that the teats can come into contact with contaminated environment is a mastitis risk.

However, when teat orifices are still slightly open after cups off, the risk of mastitis infections is much greater. It will usually be about an hour before most of the teat orifices have closed, and whilst the risk still exists after teat orifices have closed, it is obviously less than whilst they are still open.

Hence, the first hour after milking is generally likely to be the highest risk period for milking cows.

If milk can get out, bugs can get in!

In some circumstances - commonly due to less than ideal milking machine settings - teat orifices can be left more widely "open" after cups off.

They then remain open for a prolonged period of time - taking four times longer to close. Hence the risk of mastitis in these circumstances is far greater and for a far greater period.

Assessing the number of teat orifices left "open" after cups off is relatively simple for an experienced adviser, and this forms an important part of every Dairy Focus Mastitis Risk Assessment. An excessive number left "open" will contribute to a higher Overall Mastitis Risk Rating.

For milkers as well as springing and calving cows, if milk is dripping from teats, whether the cow has calved or not, the risk of infection from the environment is much greater.

If milk can get out, bugs can get in!