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Virginia Cooperative Extension - Knowledge for the CommonWealth

Dry Cows Need Heat Stress Relief Too

Dairy Pipeline: June 2006

John F. Currin
Extension Dairy Veterinarian
(540) 231-5838; email:

Since the majority of cases of mastitis occur around the time of freshening, vaccination protocols for protecting cows against the severe sickness that often accompanies cases of coliform mastitis are designed to provide maximum protection during the first 100 days postcalving. Maximum protection from UpJohn J-5 Bacterin or J-VacŪ vaccines may only last for a limited time. Cows that are far into a lactation period may not be as well protected as those animals that are less than 100 days in milk (DIM).

In the majority of milking herds, many of the cows are past 200 DIM. During recent Klebsiella outbreak investigations through the Virginia-Maryland Regional College of Veterinary Medicine, we have observed cases of Klebsiella mastitis distributed evenly throughout lactation (see chart 1). This fact has led to the concern that a large portion of many herds are not protected as well as we would like going into the summer months. Due to a multitude of factors, coliform mastitis (caused by Klebsiella and E. coli) is a bigger problem on most farms in the summertime (See chart 2). If coliform mastitis is a problem for you, discuss with your veterinarian about the need to give all lactating cows greater than 30-60 DIM a booster of your Upjohn J-5 Bacterin, J-VacŪ or Endovac-boviŪ vaccine during the month of June.

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