A major study into the causes and treatment of mastitis in dairy cows has been conducted by Teagasc.

The study on 21 dairy farms across the south of Ireland was carried out in conjunction with Kerry Agribusiness and was lead by researchers Clare Gabby and Pablo Silva Bolona.

The findings suggest that the overwhelming cause of mastitis on Irish dairy farms is staph aureus infection.

Out of a total of 2,074 cows enrolled in the study over the 21 farms, 84% of cows with intra-mammary infections was caused by staph aureus only 4.1% was caused by strep uberis.

The study found that first lactation cows had a 29.3% higher rate of infection than older cows, which the authors find worrisome because the herds used in the study all had low bulk tank SCC.


The also looked at the impact of selective dry cow therapy and found that the ideal cut off for selective dry cow therapy in first lactation cows was and SCC of 61,000mg/l and 101,000mg/l for older cows.

Speaking at the Teagasc national dairy conference in early December, Pablo said that the farmers that took part in the study also completed a survey as part of the research.

The survey found that farmers who house their cows in cubicles with one, or less than one cubicle per cow had higher SCC.

The recommendation is 1.1 cubicles per cow per day and farmers that cleaned and disinfected cubicle beds twice per day had lower SCC than those that did it once.

Farmers that routinely used the Californian Milk Test and who recorded all clinical and sub-clinical mastitis cases had lower SCC than the average.