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Cold temps no guard against dairy mastitis

Mastitis flareups occur any time mastitis organisms are given the chance to enter the teat canal. While many dairy herds have had outbreaks during hot weather, a serious mastitis problem can occur any time, including during the coldest winter months of the year.

Whether dairy cows from the milkline spend their off-milking hours in an unheated free-stall barn, outside drylot or even in a temperature controlled facility, winter conditions often creep in and tend to reverse otherwise healthy teat conditions and predispose cows to pathogens that cause udder inflammation. Fortunately, dairy producers can implement a number of preventative measures and even make some small changes to the milking ration that reduces the probability of cold weather mastitis.

These proactive measures help maintain general healthy teat skin, which normally is a very tough and pliable barrier against mastitis-causing bacteria.

Cold and dry

Cold weather associated with low humidity can quickly make teat skin dry and crack. Chapping can literary cause horizontal tears in the teat skin, which is not only painful (much like our chapped hands and lips), but allows mastitic bacteria such as staph aureus and environmental streptococci to attach to the broken skin and colonize. Cows with teat sores are also thought to be more susceptible to viral udder infections such as peseudocowspox and herpes mammalitis, which occur frequently in winter.

Keep in mind chapped teats and teat sores are not an isolated problem for cows housed only outside or in an unheated loafing barn. They can occur in cows housed in a temperature-regulated barn as well. Although, barn temperatures are significantly more moderate than those recorded outside, they still can be rather cool (ranging from 8 to 12 C) and filled with many drafts, which can easily dry teat skin, and predispose them to mastitic organisms.

From the Canadian Cattlemen website: Mastitis – To treat or not to treat

Frostbite is also a serious winter threat to dairy cows housed outside in a drylot or in an unheated facility, because teats may be exposed to freezing temperatures or high windchills for a short or extended period. Teats can freeze in temperatures close to freezing with a steady 60 km/h wind. As the temperature drops, frostbite will occur as the winds diminish to a point that teats will freeze at -18 C in still air. The degree of frostbite damage to cows’ teats ranges from a reddened and superficial skin crack, which could allow mastitis organisms to take hold or do more serious and irreversible necrotic damage to the skin, circulatory system and muscles of the teat — possibly destroying a functional teat.

Management tips

Here are a few tips to preventing chapping and more serious frostbite in cows’ during the winter as well as keeping teats in a healthy condition:

  • Limit the exposure of cows to the cold. It’s a matter of keeping the cows out of the cold temperatures and windchills. Drylots should have appropriately placed windbreaks and lots of thick dry bedding at all times. Unheated housing should also have layers of thick dry bedding and it should be cleaned to prevent a build-up of bacteria.
  • Continue with sound mastitis prevention programs. Maintain good cleaning and dipping teat protocols as well as practice sound milking procedures. Use a “winterized” commercial teat dip that contains added emollients such as glycerin or lanolin that helps keep teats soft and flexible. Once the teat dip is applied after every milking, the individual teat should be blotted dry.
  • Lower SCC with nutrition. Zinc methionine has been shown to stimulate production of keratin, the tissue that forms a protective plug in the teat canal. The recommendation for zinc methionine to lower SCC is 50 mg/kg of the total ration. Selenium fed at 0.3 mg/kg diet (6 mg/hd/d), working with 500 iu/hd/d of vitamin E during lactation and 1000 iu/hd/d during the dry period helps reduce SCC in lactating dairy cows.
  • Fight mastitis when cows are resting. Hydrated lime reduces bacteria growth in straw or wood shavings lining stalls, but this antibacterial effect lasts less than two days. Therefore, a daily application is necessary. Whether organic or inorganic bedding is used, a well-maintained stall should have adequate bedding. Up to six inches of straw, sawdust, wood shavings or sand should be put down and fill holes or bare spots. Stalls should be frequently groomed to remove wet spots and extra manure.
  • Tackle mastitis infection problems. The rate of new mastitis infections are the highest during the first two weeks of the dry period and two weeks prior to calving. It is important to work with your veterinarian in order to identify the most effective antibiotic programs tailored for your dairy farm. Research shows mastitis infections are eliminated by four means: 1) relying on the cow’s natural immune system, 20 per cent effective; 2) lactation treatments, 30-90 per cent effective; 3) dry cow therapy, 90 per cent effective and 4) culling mastitis problematic cows; 100 per cent.
  • Review the economic worth of high SCC dairy cows. Some cows are simply high SCC producers, regardless of a well-implemented mastitis prevention program. If they are high milk producers and produce a calf every year, one should evaluate her profitability to the herd and decided whether to cull her. Consider culling cows with extreme SCC counts and persistent mastitis infections.

Winter weather presents some chilling situations that compromise the teat health of milking cows on many dairy operations. Producers can overcome this challenge by implementing some pro-active steps that help reduce possible mastitis outbreaks. By eliminating even one case of winter mastitis maintains or leads to more milk revenue.

About the author

Columnist

Peter Vitti is an independent livestock nutritionist and consultant based in Winnipeg. To reach him call 204-254-7497 or by email at [email protected]

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