Growth Watch: Planning for the Last Round of Grazing Begins Now

James Fitzgerald & Séan Cummins, Teagasc GreenAcres Advisors, give advice on planning for the last round of grazing & common problems that occur at farm level when achieving the desired rotation length. They also get updates from farmers Richard Long, Co Waterford, & Martin Connolly, Co Roscommon.
The Advice
The arrival of August not only marks the transition from summer to autumn, but it forces a change in mind-set at farm level in terms of the grassland management practices employed.
Shortening day light hours, combined with cooler temperatures, will lead to reduced levels of grass growth as the housing period approaches.
To counteract this, and to both ensure the grazing season is extended and grass doesn’t run out in late September / early October, the focus must now switch to building covers at farm level.
At this point in time, second cut silage ground should be becoming available for grazing on many farms and it coincides with a period when the rotation length – or the time between each grazing in a particular paddock – should be extended.
By mid-August, the rotation length should be extended to 25 days. If you graze a field today, you will not be back here until the end of the first week of September.
By stretching the rotation length, you are giving paddocks the opportunity now to build cover to account for slower growth rates in the weeks and months ahead, with the ultimate target of achieving the peak average farm cover by mid-September.
The level of cover required will vary according to stocking rate, with 1,000-1,100kg DM/ha targeted at a stocking rate of 2.5LU/ha.
Common Problems when Achieving Desired Rotation Length
Two common problems occur at farm level when it comes to achieving the desired rotation length. The first – a relatively easy fix – is that the rotation length is too long and there is too much grass ahead of stock.
To solve this, the removal of surplus bales should be targeted. However, there is a caveat in that these paddocks should be removed during the month of August. Letting these run into September will provide an insufficient period for regrowth to achieve a grazing in the final rotation.
The second occurs where the rotation length is too quick and you find yourself re-entering paddocks in less than 25 days. To correct this, there are a number of management practices that can be implemented at farm level.
The first requires a rethink on when second cut silage was completed on farm. Was harvesting only completed in the last couple of days and is this ground struggling to come back into the grazing equation?
Where this happens year in year out, earlier harvesting of both first and second cut should be targeted to ensure that it can come back into the grazing rotation at an appropriate time, while also improving the quality of winter feed available in the yard.
This will not solve the problem this year, however, and it’s more so a change for next spring.
Alternatively, the earlier finishing of some stock may be an option. Where animals are within 60-80 days of finishing – particularly those with early-maturing genetics, the supplementation of high energy dense, cereal-based concentrates should be considered to not only move these animals off farm before a winter housing period is required but to reduce the demand for grazed grass for a group of animals.
Additionally, there’s an opportunity to top up paddocks with nitrogen in the form of protected urea now, when growth conditions are still relatively favourable. As August progresses and we move into September, the response to artificial nitrogen will reduce as soil temperatures begin to decline.
Richard Long, Ballymacarbry, Co. Waterford
- Growth: 21kg DM/ha/day
- Demand: 22kg DM/ha/day
- Average farm cover: 635kg DM/ha
- Stocking rate: 1.81LU/ha
Growth is really only starting to recover after the dry spell here. Although a growth rate of 21kg DM/ha/day was recorded, I’m expecting it to be higher over the coming week, as 20 units/ac of nitrogen were applied in recent days.
To help build farm cover, I’ve started supplementing 26 Angus and Herefords with a target of slaughtering in mid-October at an average carcass weight of 250kg.
Additionally, 6ac of reseeding was completed late last week and I hope to be back grazing this ground in approximately 40 days’ time.
Martin Connolly, Castleplunket, Co. Roscommon
- Growth: 36kg DM/ha/day
- Demand: 32kg DM/ha/day
- Average farm cover: 986kg DM/ha
- Stocking rate: 2.14LU/ha
The last round of fertiliser will be spread on the grazing ground in the coming days and will be made up of 18-6-12 or 24-2.5-10. With warmer conditions expected in the coming week I feel that it is best to spread this fertiliser now as opposed to at a later date when growth rates will be naturally reducing anyway.
The average farm cover (AFC) is strong for this day of the year at 986kg DM/ha, and so maintaining grass quality and this level of AFC is my priority for the coming weeks. One field that is going beyond grazing will be cut for surplus bales and this will mark the end of silage cutting for 2021.
The young stock are grazing aftergrass of second cut silage and seem to be thriving well. The silage ground will be grazed off late in the year and taken up from the start of 2022 in order to maximise silage quality in a naturally challenging area for spring grazing.
The Teagasc GreenAcres Programme Advisors have regular contributions here on Teagasc Daily. Find out more about the Teagasc GreenAcres Calf to Beef Programme here.