The Irish Farmers Journal visited the farm on Thursday and met with farm manager Fergal Coughlan and researcher Brian McCarthy who are running the experiment. The trial is now in its third full year comparing milk and grass production on clover and non-clover swards.

“So far this year there has been very little differences between the herds, with each having produced about 165kg of milk solids per cow. But in the last fortnight the cows on clover have really started to ramp up production and are producing an extra 0.1kg milk solids per cow at 2.04kg milk solids per day versus 1.92kg for the cows on grass only.” Fergal says.

According to Brian, this is following the trend of previous years where differences in milk production only emerge from around May onwards, when the percentage of clover in the sward increases.

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However, the percentage of clover is the sward is lower this year at about 10%, when in other years it would be 15 to 20%. He cites the colder weather in March and April as being the likely cause.

Grass growth is flying it at the moment so the cows are off all supplement and about 30% of the grazing platform is now closed up for silage.

Increase in supplement

With heavy rain and poor growth rates this spring, more supplement was fed than in previous years, to both the grass and grass plus clover cows. To date, there has been 260kg of meal fed to each group and 330kg of silage fed to the grass only cows and 470kg of silage fed to the grass plus clover cows.

So an extra 140kg of silage was fed to the cows grazing grass and clover this spring. Last year, in a more favourable spring, an extra 180kg of silage was fed to the cows on grass and clover, so the differential in extra feed required in spring between the two treatments is getting smaller.

Fergal puts this down to the way paddocks were closed last autumn; “the first paddocks we closed had low clover contents which wintered well so our opening grass cover was higher. Any paddock with a really high clover content was grazed last so we weren’t relying on these fields for early spring grass. In previous years we found that carrying over high covers of clover lead to excessive die back in the sward which meant our opening farm cover was lower than we needed so extra feed was required in spring to make up the gap.”

Last year, the cows on grass and clover produced an extra 58kg of milk solids per cow.

See next week’s Irish Farmers Journal for a full report.