The person who is administering the dry cow therapy should be advised to among other things:
- Wear a clean pair of gloves for each animal. This will cut down on cross-contamination. We recommend the use of disposable nitrile gloves for this. Clean teats with clean paper towel.
- Make sure the teats are clean and dry before inserting the dry cow tube.
- Pre dip the teats. Allow for 30 seconds contact time.
- Wipe dry with clean paper towel again.
- After the teat has been thoroughly cleaned, disinfect the whole teat by scrubbing with cotton wool soaked in methylated spirits.
- Start by scrubbing the front teat furthest away from you and then the near front teat to reduce risk of contamination.
- Administer the dry cow therapy starting with the near front teat and massage into the quarter to disperse the antibiotic.
- After administering the dry cow therapy, disinfect the whole teat as before and insert the teat seal*. Then administer the sealer which should be left to sit in the canal of the teat. Allow at least 30 seconds per teat. Use methylated spirits and cotton wool until the cotton wool comes away clean.
- Clean back teats starting with teat furthest away from you with methylated spirits and cotton wool, administer dry cow therapy and massage (beginning with the near back teat)
- Disinfect the teat again to remove any contamination and administer the teat sealer. Do NOT massage. Avoid nozzle contamination.
- Spray or dip teat after tube insertion.
- Allow cow to stand in a clean environment for 30 minutes.
When drying off cows select SMALL groups and dry 15-20 cows each day. This will ensure greater attention to detail.
Dry off after morning milking.
Milk out completely, do NOT leave milk in the udder.
This information was condensed from "Drying Off the Dairy Cow" It's Your Field Magazine, Autumn 2014
Risk of Infection
The diagram above shows the periods of relative risk of acquiring a new infection while a cow is dry. The first period of risk is when the cow is initially dried off. However after 1 to 2 weeks the risk is much lower as the natural teat plug has formed and the udder contains the high levels of lactoferrins and other natural inhibitors.
The second significant risk period is just before calving when the cow is springing and also when she is calving down.
By this time the concentrations of natural inhibitors in the udder has reduced as the cow starts to bag up with colostrum/beastings and frequently the keratin plug drops out around this time. To compound this problem, the antibiotic from the dry ow treatment will have reduced to below therapeutic levels unless the cow has a particularly short dry period.
These risk periods are reflected in when mastitis occurs during the next lactation. Work done in the early 2000s showed, not unexpectedly, that many cases of mastitis that occur in the first month after calving were acquired during the dry period. More surprisingly was that some clinical cases that cropped up 8 months into the lactation, also originated from infections acquired during the dry period. Up to 60% of all clinical cases of mastitis during lactation originate from infections acquired during dry period.
Dry periods should be at least 6 to 8 weeks long.
2 weeks after drying off and a week either side of calving are the main periods for acquiring new infections.
This information was condensed from "Dry Cow Therapy" It's Your Field Magazine, Autumn 2015