Grass+: slow growth and falling average farm covers

The cold weather over the last seven days has caused a reduction in growth rates from previous weeks.

The average growth rate over the last seven days recorded by farms using PastureBase Ireland is 34kg DM/ha/day. Predicted growth rates from Elodie Ruelle’s MoSt Grass Growth Prediction Model (map top right) are on the rise again with a forecast for higher temperatures this weekend and into next week.

Growth falling

The slowing growth has resulted in average farm cover (AFC) falling rapidly on many farms.

In many cases concentrate feed has been increased and silage in the form of high-DMD bales is now being fed in an effort to reduce demand. By reducing the allocation of grass per day you reduce the daily demand.

During periods of low growth, matching growth and demand will hold the AFC.

Maintaining the AFC above 550kg DM/ha will help avoid running short of grass during the second round.

Grass walk

At this time of year, grass growth can accelerate in the space of a few days. A weekly grass walk will help ensure quality grass is always available.

Once growth picks up again silage should be removed from the diet and concentrate feed reduced accordingly.

Sward Watch

Caroline O’Sullivan – Teagasc Curtins Farm, Co Cork

The cows began the second round on 6 April and the first paddock had a pre-grazing cover of 1,300kgDM/ha. Our C/LU (cover per livestock unit) is 180kgDM/LU. We skipped the last paddock in the first round and took it out for bales in order to get it back into the rotation.

Cows are milking well and there is a lot of bulling activity. We plan to start breeding on Saturday 24 April. We have started reseeding and three hectares are done so far.

We are cutting paddocks for bales and once they green up we are spraying them off. The cows are being followed with one bag of ASN per acre.

Michael Ryan – Cashel, Co Tipperary

I started the second round on 2 April. I don’t like to drop the AFC any lower than 650kgDM/ha and this helps to avoid hitting a tail spin towards the end of the second round.

I increased the concentrate to 5kg and in the last week I reintroduced 76DMD baled silage to the diet. The cows are currently being allocated 8kg of grass, 5kg of silage and 5kg of concentrate.

I am following the cows with 25 units of nitrogen per acre. I have started recording pre-breeding heats and I top up the tail paint every three to four days. We plan to start breeding on 25 April.

Peter Mongey – Slane, Co Meath

We started the second round on Monday 11 April. The cows have been indoors by night since the end of March as average farm cover was low and we needed to reduce demand.

Cows are being allocated 6kg of silage and this will be taken out of the diet once growth increases.

Cows are grazing covers of 1,400kgDM/ha and graze-outs have been excellent.

We started pre breeding heat detection in early April and plan to start breeding on 24 April.

The whole farm got two bags of 18:6:12 per acre last week on top of the 60 units of nitrogen per acre that was already out.

James Strain – Burnfoot, Co Donegal

It is quickly becoming a very difficult spring for us here. Thankfully there is plenty of silage in reserve and I have more stock sold than I normally would have at this point. So far, I have just seven cows and calves out at grass. They were turned out nearly a month ago but no other stock have joined them since.

I had planned to get stock out last weekend but we ended up having snow showers so that idea was put on hold once again.

The average farm cover is low because there were lambs grazing some of the farm over winter including most of the silage ground.

I will turn stock out on to any silage ground that does need grazing from this weekend and get it grazed off before closing for first-cut.

Iarlaith Collins – Newford Herd, Athenry

All cows and calves are now out at grass. We are just starting the second rotation and one group of cows and calves is being supplemented with baled silage in order to slow the rotation slightly.

I would expect a burst of growth once the temperatures increase over the coming days and silage feeding can cease.

This week we have stitched in clover on some of the grazing ground at a rate of 2.5kg/ac. This was done directly after a tight grazing to remove as much grass as possible. The plan is to graze this area at low grass covers for the rest of the season to allow the clover plant a chance to establish.

Silage ground was closed on Monday this week with a target cutting date of 20 May.

Shaun Diver – Tullamore Farm, Co Offaly

At this point, there are over 80 cows and their calves at grass grazing in three groups. There are also almost 200 ewes and their lambs back out at grass at this point.

They are being fed meal at grass for the first 10 days at pasture and then are being given a high-magnesium bolus to try and combat any tetany issues in the ewes.

The cows have high magnesium lick buckets with them at all times and I am supplementing the water as well.

Any ground that has been grazed over the last 10 days is very slow to come back due to the colder conditions and frost at night. As a result our growth figure is well behind where it usually is in mid-April.