Mastitis

A significant problem...

This remains one of the most common health issue of dairy cows. Undoubtedly you are bombarded with information but lets be concerned with the here and now.

Most of the mastitis around calving is due to the environment, so as much as possible have yoru cows calving in a clean, grassy paddock.

Strep Uberis in particular is commonly isolated and this is almost invariably sensitive to penicillin. So injectable products eg Mammyzin and intramammary eg Penalone which contains straight penicillin are effective. Treatment results can be improved with the use of Oxytocin to aid complete milkout of mastitic glands and also Metacam which reduces the amount of inflammation and lowers the somatic cell count quicker.

Sometimes a longer treatment course is needed, particularly with those products that recommend 3-12 hourly treatments. Doubling the treatment course (as well as the withholding period) significantly increases the bacteriological cure as well as a clinical cure. As a very general figure, an intramammary course of treatment may resolve the clinical signs of mastitis so the milk can be put in the vat, but the causative bacteria can be isolated in at least 50% of these. Increasing the treatment length and/or the dose rate increases the bacteriological cure rate so that the causative bacteria can only be isolated from 20-30% after treatment.

From about a month after calving the frequency of contagious pathogens incrases particularly Staph Aureus. These are less sensitive to the straight penicillins and you may have to use the potentiated penicillins eg Clavulox or Rilexine. It is always a good idea to collect a milk sample before treatment and put it in the freezer so that if your treatment doesn’t work it can be tested to identify the bacteria and what drugs it is sensitive too.

Otherwise don’t forget the other SAMM recommendations. In particular your milking machine should have had a WOF over winter. Liners need to be changed regularly and cows need to be teat sprayed every milking. In regards to that make sure your disinfectant and emollient concentrations are adequate and that the entire teat is covered. One strategy particularly with heifers is to collect freshly calved heifers for milking twice a day. If you bring them into the colostrum mob in the morning for their first milking that evening, then it is possible if a heifer calves immediately after that it will be 38 hours before she is first milked. In a New Zealand trial comparing once daily removal of heifers in the morning and milking in the evening, the average time from calving to first milking was 22 hours (range 11-38 hours). With twice daily collection with immediate milking, the average time from calving to milking was 5 hours (range 2-9 hours).

In the first group of 242 heifers there were 35 cases of mastitis in the first 21 days.

Out of 239 heifers collected from the springing mob twice daily there were only 19 cases of mastitis in the first 21 days. This is a 40% reduction.

Early milking does remove bacteria from the udder before it establishes an infection. It also reduces udder oedema and allows the teat canals to close which are risk factors for mastitis.

Please contact us to talk about which treatment options are best suited to your farm.