In February 2002, the Australian Dairy Herd Improvement Scheme released a new tool for dairy farmers to use to manage mastitis.

The new ABV (Australian Breeding Value) for cell counts in milk enables Australian farmers to buy semen from bulls whose daughters will be genetically more resistant to mastitis. How does it work and what are the implications for your mastitis control program?

High cell counts in milk are caused by mastitis, a bacterial infection of the udder. Most infections occur when bacteria enter the quarter through the teat end.

Anything that helps reduce the number of bacteria at the teat end, increases the health of the teat skin, or helps the cow’s immune system fight infections will assist mastitis control.

Good day-to-day management on farms has the greatest impact on the level of mastitis in dairy herds. The risk of mastitis can be increased by, for example, using a teat spray at a low concentration or having wet and muddy laneways. Both will increase the number of bacteria at the teat end and therefore the risk of mastitis. Removing teatcups roughly can force milk droplets from the outside of the teat through the teat end, and may carry bacteria into the udder. Milking machines that are not performing optimally may damage the teat end thereby making the cow more vulnerable to infection.

A cow’s natural genetic resistance also plays a part in mastitis control. For example, the mix of genes she receives from her parents may mean she has healthier teat skin than other cows, or teats of a size or shape that are less prone to damage.

The new milk cell count ABV enables farmers to improve the genetic resistance of their herd to mastitis at a low-cost.

To achieve low milk cell counts - in both short and longer timeframes -, farmers should apply good mastitis management on farm and choose semen from bulls whose daughters are more resistant to mastitis. The Countdown Downunder Guidelines for Mastitis Control give detailed recommendations of management practices that will help protect your herd against mastitis.

For more information on the somatic cell count ABV, visit the ADHIS website at www.adhis.com.au.

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