|Missouri Dairy Business Update|
|Volume 4, Number 5|
Prevention of new intramammary infections during the dry period using an internal teat sealant.
Barry Steevens 04/30/04
Standard procedure for maintaining a healthy mammary gland at calving is to treat the dairy cow with a long lasting antibiotic at "dry off". This helps eliminate existing intrammammary infections and prevents new infections for the first two weeks of the dry period. It has been assumed the teat end is closed with a keratin plug to prevent further introduction of infectious bacteria. However, researchers at Kansas and Iowa reported that up to 20% of the dry cows may have an open teat end at six weeks of dry off. In addition, high producing cows at dry off can be observed leaking milk 12-24 hours after dry cow treatment, therefore some cows will have minimal protection to mastitis causing pathogens.
The use of an internal teat sealant containing 65% bismuth subnitrate in heavy liquid paraffin ( Orbeseal, Pfizer animal health) has been researched. In cows uninfected at dry off the product has been shown to be as effective as antibiotic dry cow therapy alone.
Control of contagious pathogens is an issue on most modern dairies and blanket dry cow therapy remains essential. The use of a teat sealant in conjunction with antibiotic therapy was reported on by University of Minnesota researchers. In a trial on 437cows all were quarters were infused with a commercially available long acting dry cow antibiotic. Two diagonal quarters were then infused with the teat sealant. During the dry period each cow had all four quarters treated with an antibiotic and two diagonal quarters were infused in addition with the teat sealant.
The "sealed quarters had a 30% less likelihood of developing a new intramammary infection between dry off and day 1-3 after calving. They also were 33% less likely to develop a case of clinical mastitis between dry off and 60 days in milk.
In another study of 3 commercial herds of 608 cows in Wisconsin there was a 25% decrease in somatic cell level at calving for cows treated with the teat sealant.
Udder health during the dry period sets the stage for a profitable next lactation.