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As we head into winter, it is common in many parts of the country to see a significant seasonal rise in somatic cell counts. This is often associated with a rise in the rate of new subclinical infections.
One of the most effective things we can do to control this is to maintain good teat skin condition. Colder, wetter weather tends to increase the prevalence of skin condition issues. It also is the time of year when we tend to be the most aware of problems and are looking for them.
The following checklist may be helpful in reviewing whether a significant problem exists and what the options are for minimizing those risks.
It is important to make a distinction between callus formation at the teat end and chapping that leads to cracks in the teat skin. Callus formation is influenced by teat shape and size. More than anything, it is related to milking machine function. While there is some seasonal variation, callus formation tends to be there in some form year-round. Chapping and cracking of the teat skin are much more dependent on extremely cold winter weather.
Both of these conditions make the teats much harder to keep clean. However, there is some indication that cracking of the skin greatly increases the ability of bacteria to colonize and maintain themselves. This often leads to higher levels of new infection, particularly if the cracking produces open sores.
The most obvious thing you can do is minimize conditions that predispose cows to skin problems. Providing some protection from the full effects of temperature and wind can really help minimize these effects. Moisture on teat skin tends to drastically increase the effects. So make sure that teats are dry when cows leave the parlor and that they remain dry between milkings.
Minimizing additional teat stressors, primarily those associated with milking time, is important. Proper milking machine function and liner type ensure that teats are not being poorly massaged or overmilked. Remember that milking vacuum can be a problem if it is too high or too low. Pulsation can be a problem if it’s too fast or too slow.
Probably the most significant machine-related contributor to teat problems is time spent with the milking machine attached and low milk flow. This can be a problem both at the beginning and at the end of milking.
Milking procedures can also have a significant effect on things like claw time. So remember that not all machine-induced issues are fully correctable just by adjusting the milking machine.
Another "stressor" is the condition of teats and the udder at freshening. Excessive udder edema or poor environmental conditions prefresh may predispose the animal to more infections at freshening that may or may not be evident as clinical cases.
Milking procedures can help not just in maintaining skin condition but also in controlling the risk of new mastitis infections. Proper teat dipping with a product that has known germicidal activity is even more important for controlling bacteria levels at the teat end when skin condition is not as good.
One of the most costly mistakes I see is to discontinue teat dipping during extreme weather. If your herd has any level of infectious mastitis organisms present, these can literally explode if teat dipping is stopped even for a short time. The best strategy is to continue to use a teat dip that is proven to both help prevent bacterial infections and improve skin condition. Either blotting off excess dip or allowing additional time prior to letting cows out into conditions where teats might get frozen is well worth the investment.
Selecting a teat dip with extra skin conditioners make a big difference. But these additives can affect the ability of the dip to kill bacteria. Make sure your teat dip supplier has solid information to support the dip’s ability to control bacteria growth as well as to provide extra conditioning during harsh weather.
MARK WUSTENBERG, DVM, works with Tillamook County Creamery Association in Tillamook, Ore.
You can contact him at firstname.lastname@example.org.