Dairy farmers should carry out a blood test on their cows a few times a year, according to Folke Rohrssen, a vet from Cahir, Co. Tipperary.

Rohrssen was speaking at a Eurogene information meeting which took place on Thursday (January 19) in Mullingar, one of a number of these events taking place throughout the country.

A number of topics were covered at this meeting, including the significant challenges that will be faced by every dairy farmer in planning their breeding strategy for 2023 and beyond.

Minerals play an importance role on farms, with farmer very aware of the importance of feeding minerals pre-calving to reduce issues around calving.

But they are also important for ensuring that cows are in a good position to go in-calf in the breeding season.

Blood test

Rohrssen discussed the importance of checking the mineral status of cows to ensure they have a high level of fertility and to reduce sickness.

“A feed analysis will only tell you what a cow could be getting, not what she is actually metabolising,” he said.

“In order to know what is happening you need to do a blood test a couple of times/year.

“I would recommend at least three or four times/year for the first few years at least, to know what the pattern on the farm is.

“You have certain soils, which can be high in molybdenum and iron, that could come in from the ground or water.”

Rohrssen explained that iron and molybdenum interferes with or inhibits the absorption of copper.

Continuing, he said: “In order to get a full picture of what the cow has available to her we need a blood test, but we also need another jigsaw piece in that puzzle – which is what is in the feed, [and/or] do we have something interfering with, inhibiting or binding some of the trace elements.

There can be either a primary or secondary deficiency, he explained.

“Primary deficiency is [when] the cow isn’t getting enough and secondary deficiency is [when] the cow would have enough of it but it is not getting into bloodstream because it bound along the way in the rumen.”

Rohrssen explained that most of the mineral absorption takes place in small intestine, not in the rumen.

Commenting further he said: “I think it is quite important that farmers do a mineral blood test on their cows. We would recommend it pre-calving, pre-service, peak production and then pre-drying-off.

“Those are times that you can action on these results and put something into place that will balance out a deficiency or even discover an over supply of minerals.”

Rohrssen explained that selenium and copper are the two element which if they are in an over-supply they can suppress fertility in cows.