Michael Fitzmaurice

Low Temperatures Limit Grass Growth on Farms

Michael Fitzmaurice

Due to the recent spate of poor weather, a number of farms have witnessed grass growth levels close to zero on some days. As a result, farmers have been forced to dip into their fodder reserves.

“This is the reality of what is going on. Farmers are hoping that the weather will improve shortly,” said Teagasc dairy specialist, George Ramsbottom.

“Due to grass shortage, dairy farmers are being forced to supplement their herd’s diet with silage and meal to try and maintain milk solids. This has resulted in on-farm costs being driven up on farms this spring.”

Varied grass regrowth levels have been recorded in parts of the country, with Teagasc’s PastureBase showing an average grass growth rate of 15kg Dry Matter per hectare per day (Kg DM/ha) on both Teagasc dairy research and commercial farms.

“Typically it would be expected to see growth rates of almost double this at 25-30kg DM/ha per day in late March so that’s half of what we’d normally expect,” George explained. “The reason for such low growth rates is the low temperatures – a key driver of grass growth in early spring. Currently temperatures are averaging 7ºC on farms which is almost 2ºC lower than normal.”

“At this stage we should be seeing grass covers on the first grazed paddocks of 1200kg DM/ha. In most cases we have only seen half of that, at 500-600kg DM/ha. Our advice to farmers is to keep Nitrogen spread in line with their annual fertiliser plan, and continue to supplement, while they wait for grass growth to catch up,” said George.

Teagasc advises farmers to go back and look at the first fields grazed to decide if action needs to be taken. Speaking at the recent series of Teagasc Spring Grazing Farm Walks, George Ramsbottom said: ‘Walk the farm. Pay particular attention to the covers on the early grazed paddocks. Firstly, maintain a rotation length over the whole of the grazing platform of at least 20 days. Supplement with silage and meal to feed the cows adequately.”

“When the recovery commences, phase out the silage feeding first and you should see an increase in grass intake by the cow and protein per cent in the milk. Then as grass covers increase, reduce the amount of meal fed. Thirdly, start to close up fields for silage. The last thing we want to do is to sacrifice body condition of the dairy cows just before the breeding season begins,” George explained.