Mastitis is costing Irish dairy farmers over €100m a year, Dr Laurence Shalloo from Teagasc told an Animal Health Ireland (AHI) conference in Kilkenny on Wednesday.

In 2014, mastitis cost €80m per year at farm level and by 2023 that increased to over €100m, Shalloo explained at the conference, which focused on improving somatic cell count (SCC).

However, this increase in cost is despite a significant reduction in cell count during that period. SCC at farm level dropped from a peak of 272,000 cells/ml in 2009 to a low of 175,000 cells/ml in 2017. In 2023, cell count crept up to 190,000 cells/ml.

Increased SCC bears significant cost at farm level and while 46% of costs associated with mastitis are down to the cost of culling cows, another 40% of the costs of mastitis are due to reduced milk yield.

Farmers, Shalloo said, often focus on penalty costs (7%) from the processor and the cost of diagnostics and treatment (7%) and sometimes overlook the cost of reduced milk production. “Even at a cell count of 100,000 we’re losing about 150 litres of milk in a lactation. There is a milk yield effect when cell count goes up,” Shalloo said.

As cell count moves from less than 100,000 cells/ml to between 100,000 cells/ml and 200,000 cells/ml, the cost is 0.9c/l up to a cost of 3.6c/l for those herds that are over 400,000, Shalloo explained.

On a per-hectare basis, for herds that are over 400,000 cells/ml the costs associated are between €500/ha and €600/ha.