Selective Dry-Cow Therapy

   Many folks in the dairy industry are beginning to question the almost universal practice of dry-cow treating all their cows with intra-mammary antibiotics.  This is done in the hope that it will cure existing cases of subclinical mastitis and to prevent new cases from occurring at calving. 


    Probably the main reason for this change in thinking is the growing evidence that antibiotics used in livestock can result in antibiotic resistant strains of bacteria that are difficult to treat in humans.

    It doesn’t take a rocket scientist to figure out that one way to reduce antibiotic exposure is to only treat the animals that need treatment. Duh!    Research has indicated that as many as 70% to 80% of quarters are not infected at dry-off, and thus may not require dry cow therapy.

   The key to selective dry cow therapy is to identify the the cows and quarters that need treatment.  There are several options recommended to accomplish this, including: The California Mastitis Test (CMT). somatic cell count (SCC) tests, veterinary lab culturing of milk samples, and using on the farm culturing labs. The sensitivity rate of these procedures varies from 50% to (90% accuracy. 

   All of this costs time and money.  The University of Minnesota has estimated that the payback for selective dry-cow therapy is $2.62 per cow.  

    For dairymen who are unable or unwilling to do this, there is a tried and true, low tech way to identify the infected cows.  When it’s dry-off time quit milking the cow. It takes five or six days for the cow’s hormonal system to switch from milk production to no milk production.  After this five or six days, sanitize the udder and milk out some secretion.  It should look like regular milk.   Any abnormal signs in this secretion - watery, clotting, bloody, snotty, off color, bad odor - is an indication of infection and that quarter should be treated.  Whether the milk if normal or not, a good practice is to milk out all quarters at this time to aid in the involution of udder tissue. 

    Conventional dairymen will probably treat affected quarters with antibiotics.  It is also recommended to infuse teat sealants into all quarters. That procedure can introduce infection into the unprotected mammary gland. 

   Holistic or organic dairymen have more choices;  colostrum-whey products, herbs, homeopathy and others.  If using these products. it is best to check the milk every four or five days and treat again if indicated.  This methods supports and enhances immune response and works with the innate physiology of the animal.  These treatments generally work well in animals whose immune system is not already greatly compromised by stress, malnutrition, or exposure to toxic ag chemical in their environment.