Developing effective grassland management systems for sheep was the theme recently addressed by Dr. Phil Creighton, during his presentation to the 2022 College of Agriculture, Food and Rural Enterprise (CAFRE) Virtual Sheep Conference.
According to the Athenry-based Teagasc research scientist, average mid-season stocking rates on Irish sheep farms are averaging eight ewes/ha.
However, the equivalent figure on research farms is 12 ewes/ha. And this difference is reflected across all aspects of performance.
Where 2019 figures are concerned, the net margin per hectare being achieved on commercial farms averaged €129; the equivalent figure at research level was €544.
"Grassland utilisation is a key driver of profit within all sheep enterprises,” Creighton explained.
“On commercial farms this is currently averaging 5.6t/ha, whereas on a research unit, a figure of 10t can be achieved.
“Doubling grass utilisation can improve sheep profit margins by a factor of four.”
According to Creighton growing 1t of grass dry matter (DM) per year will meet the needs of a single ewe and her lambs.
This figure is based on an 85% grass utilisation rate and the implementation of a rotational grazing system.
Grazing sheep
The Teagasc representative pointed to five key components within the grazing management jigsaw for sheep.
These are:
- Soil fertility;
- Grazing infrastructure;
- Grazing management;
- Grass budgeting
- Reseeding.
“Paddocks form the basis of all rotational systems and they must be managed with the following principle in mind - grow grass for three weeks; graze for three days," Creighton said.
“At the height of the grazing season, it takes grass plants 21 days to regrow three full leaves. In the shoulders of the season this process will take that little bit longer.
"But the principle remains that of grazing grass at those times when it will deliver the maximum return in terms of animal performance.”
Paddocks
Creighton pointed out that paddocks improve grass utilisation and production.
They act to improve animal performance while giving the farmer greater flexibility in terms of the management priorities for the business.
Paddocks can be permanent in nature or they can comprise a series of temporary divisions.
Creighton cited the example of 100 ewes and their lambs having access to a 2ha field.
Based on an initial cover of 1,200kg/DM/ha, i.e., grass at a height of 8cm, it should be possible to graze the area out in six days, using an equivalent number of temporary divisions.
Creighton added: “This approach ensures that the ewes and their lambs receive 400kg of grass dry matter per day and that the grass is being offered at a rate of one ha per day.
"This commitment fully complies with the three-day grazing rule of thumb.
“Teagasc research has confirmed that the use of additional, temporary paddocks can increase grass utilisation rates by up to 15%.”
