Control of Mastitis and Somatic Cell Count is Critical in Wet Weather

The emphasis on mastitis control should be prevention. The keys are proper sanitation and management of non-infected and subclinically infected animals.

Wet, manure-laden areas in the lactating and dry cow pens and bedding areas, and poor sanitation during the milking process increase the risk of mastitis. Udders should be clean and dry when milked. Teats should be sprayed or dipped with disinfectant after milking.

Research has documented the fact that wet, muddy conditions are correlated to increases in somatic cell counts (SCC). The relationship is indirect, however. Somatic cell counts are a direct reflection of the infection status of the gland, and so when the cell count rises, it reflects an increase in the new infection rate. Exposing the teat end at milking and between milkings to huge numbers of environmental bacteria heightens the probability that more new infections will result, and this in turn increases the cell count.

The task remains to produce a clean, dry teat at milking time, and it is even more critical when the conditions are challenging. If your somatic cell count is over 600,000, then you should consider changes in management to decrease the SCC.

1. Review your facilities to see if mud or other wet areas are contributing to the high SCC. Check the vacuum and pulsation to verify that they are functioning properly.

2. Review your milking practices to verify that udders are clean and dry when being milked. Consider using individual cloth or paper towels to decrease the spread of the infection. Use latex gloves to milk if udders are dirty.

3. After cows are milked out, it takes a period of time before the teat opening completely closes tight and provides a physical barrier to prevent bacteria entry. If at all possible, keep cows on their feet for 30-45 minutes immediately after milking to allow the streak canal to close. In addition, it is critical to apply a protocol tested, post milking teat dip immediately after milking, preferably one that also provides high levels of emollient or provides a pliable, flexible film that coats the teat and teat end and resists cracking and peeling. The germicide helps kill most bacteria that may be on the teat end after the units are removed and minimizes the risk of new infections.

4. Run a SCC on the herd to determine which cows have a high SCC and milk them last. Run a culture on milk from some cows to determine the cause of the mastitis and then do a sensitivity test to determine which antibiotic(s) would be most useful in treating cows.

5. Treat selected high cows with antibiotics in conjunction with your veterinarian and monitor their response to the antibiotic. If the herd SCC does not decrease, resample the herd to determine cows with a high SCC. Follow recommended withdrawn periods for antibiotics.

6. If the SCC appears to be increasing, you should discuss the use of a vaccine for mastitis with your veterinarian. The vaccine is most recommended for use on healthy cows as it may give a temporary increase in SCC but is sometimes the only alternative left to decrease the level of SCC.

7. Dry treat all cows and discuss the possibly with your veterinarian of double treating some cows.