Concerted efforts are underway today (Thursday, June 1) to identify the source of an illness which has impacted cows chiefly in the south of the country.

A number of organisations including Teagasc, various co-ops and other bodies are currently engaged in examining reports from private veterinary practitioners about dairy cows who developed diarrhoea and experienced a sudden drop in milk yield.

For the last eight weeks Cork Regional Veterinary Laboratory (RVL) has collated reports on the illness which has been reported by various private veterinary practitioners and in herds in Co. Kerry, mid-west, north, and easy Co. Cork. 

According to Dr. Joe Patton, Head of Dairy Knowledge Transfer Department at Teagasc, the authority is aware of approximately 100 different cases todate.

He said most of these had occurred between mid-April to early-May, during times when weather was “very challenging”.

The Department of Agriculture, Food and the Marine (DAFM) has stated that it suspects it is “subacute or acute ruminal acidosis (SARA)” however Dr. Patton said that it is “not clear cut”.

He outlined that while there have been increased reports of SARA, Dr Patton said “we can’t just decide that it’s SARA, we’d need strong evidence of that”.

According to Dr Patton some members of Teagasc have been on farms to try and resolve the issue and some co-ops have also taken blood samples and are working their way through different tests to try and identify the problem.

SARA

According to DAFM SARA is a metabolic condition associated with the transition from housed diets to lush spring pasture. 

The department has highlighted that it now occurs annually in late April and May in Cork,Kerry dairy herds.

DAFM said that affected cows typically have a slight or moderate reduction in appetite, loose faecal consistency, and sometimes reduced rumination but they do not have a fever. The most consistent sign and the main concern is a sudden drop in milk yield. 

According to the department most affected cows remain clinically well and the majority make a recovery within about a week of a change of pasture with milk yield quickly returning to normal levels.

DAFM said it’s important to note that this syndrome has no implications for food safety. 

Reasons for illness in cows

According Teagasc indications from some farm visits suggest a change of diet and cooperation with vets would lead to recovery of suspected illnesses over the course of a week.

Dr. Patton said: “Grazing conditions were difficult this year. Grass intakes or the intake of pasture from the herds were under pressure or too low.

“We found that some farms were short on good quality silage and they were trying to fill the gap with meal.”

Teagasc guidelines outline that a certain amount of forage is needed in the diet to keep ruminant function correct.

They recommend at least 13 kilos of dry matter. If there is not enough grass, then silage should be added to the diet.

Dr. Patton said: “It’s not that there’s a problem with spring grass. It’s a problem with not enough spring grass.

“It sounds like SARA and that’s something that’s always been around, but the issues have deepened a lot more this year with the weather”.

However, he said that “in in the absence of hard data and in the absence of a full veterinary investigation or a diagnosis, it’s very difficult to say definitively what the underlying cause is.”

Dr. Patton advised that people make sure to have enough silage in the yard at all times, so if “challenging conditions” do occur people have the capacity to supplement fully with good quality forage to make sure cows are kept healthy.