Milk Cultures

Mastitis is the number one disease behind antibiotic use in the dairy industry. Over 90% of cases are caused by bacteria. In NZ around 90% of these “bugs” can be treated with common antibiotics. So why bother finding out what, in particular, is “bugging” your cow?


Big globs of pus in a SA infected cow at post-mortem

Growing a bug(copy)Growing or culturing bugs tells us:

Where the bugs are coming from?

If we know where they are coming from then we know where to stop them. For example Staphylococcus aureus (SA) is a bug that is spread from cow to cow; CNS bugs are found on the skin of cows naturally; Streptococcus uberis (SU) is found in mud and faeces; Streptococcus dysgalactiae (SD) likes damaged teats. Control of SA is focused around management of infected carriers; CNS around teat disinfection; SU around reducing environmental contamination and SD around eliminating teat end damage.

This means you focus resources on the right area to reduce mastitis saving time and money.

What drugs are going to work?

Pseudomonas aeruginosa, E. coli and enterococci are resistant to a lot of antibiotics and 

anti-inflammatory drugs are necessary to get a good result in these cases.

How long we need to treat the cow to kill the bug?

For example CNS and SU respond well to short courses (three tubes) of most antibiotics. However SA needs extended therapy (five or more tubes) to ensure a reasonable cure rate in lactation. Getting this right at the beginning means you save money by not over treating cases that will cure quickly and you get a better outcome for cows that need extended therapy.

Who should be culled?

Bugs such as CNS, coryneforms, SU and SD will cure easily. Other bacteria such as chronic SA and Nocardia spp. are very difficult to cure. In order to safeguard the rest of the herd these will need to be culled or managed away from the main mob. 

Franklin Vets will be offering in-house bacterial cultures from the middle of August this season based at the Pukekohe clinic. Find out quickly and cost effectively what is “bugging” your herd. Get
better results and save time and money.


David Hawkins BVSc