Is there ongoing/upcoming research that is looking at this? What are some of the options that are available to manage mastitis in dairy cows under the organic management system?

Currently the method of choice for treating cows with mastitis in conventional dairy farms is using antibiotics. However, in organically managed dairy farms, using antibiotics to treat a cow one time per year will result in a 30-day milk withdrawal. If the antibiotics or any other drug is used twice per year on a particular cow, that cow will lose its organic status and need to go through a 12-month transition period. If 35% of the herd is affected by mastitis, then, this will have devastating economic consequences on that herd. Therefore, organic dairy farmers are in search of the best potential products that are allowed to be used with no negative impact on the cow’s health and the farm itself.

Besides various oral supplements that can be used to boost immunity of cows prior to calving or plant-based cream products applied externally when cows are sick, another way to lower the incidence of mastitis is vaccination at drying off. There are several commercially available vaccines that have been approved for use in dairy cows as follows:

a) ENVIRACORTM J-5 vaccine (manufactured by Zoetis, Parsippany, New Jersey) is an Escherichia coli vaccine administered at drying off, 30 days later, and again at 14 days after calving. Results have shown an 80% decrease in the incidence of mastitis.

b) J-VAC ® Escherichia coli Bacterin-Toxoid (manufactured by Merial Ltd.) is another E. coli vaccine administered at drying off and then 2-4 weeks later for a boost. The vaccine lowers coliform mastitis by 60%.

c) ENDOVAC-Dairy® (manufactured by Immvac Inc., Columbia, Missouri) is a Salmonella typhimurium-based vaccine administered during the dry off period with a boost 2-3 weeks later. Studies have shown a 42% decrease in the rate of coliform mastitis.

d) Staphylococcus aureus vaccine (Lysigin®, Boehringer Ingelheim Vetmedica, Inc.). This is the only commercially available vaccine against aureus. The vaccine needs to be administered multiple times according to the manufacturer’s instructions. The vaccine has been shown to lower the incidence of new mastitis cases by 52%.

When making decisions about vaccination, it should be kept in mind that most cases of mastitis are caused by Escherichia coli (21%), environmental streptococcus (11%), Klebsiella (7%), Staph aureus (3%) and coagulase-negative staphylococci (3%).

– Dr. Burim Ametaj, Professor, University of Alberta