Over 100 farmers and industry delegates attended Tuesday’s Irish Grassland Association sheep conference and farm walk. The event, sponsored by G€N€ IR€LAND and Mullinahone Co-op, took place in Aughrim, Co Wicklow, with a farm walk taking place in the afternoon on the farm of John Pringle.

A focus running through the event was the importance of grassland management and its potential to underpin profitable enterprises. This was evident in all of the morning presentations and again in the afternoon where host farmer John Pringle’s enterprise is based on mixed grazing his 50-cow suckler-to-beef herd with a flock of 250 mature ewes and 70 yearling hoggets and their lambs.

While covered in a sheep feature in recent weeks, witnessing the farm run this number of animals in just three grazing groups showed what can be achieved at farm level and proves that rotational grazing systems can be set up to account for different flock/herd sizes and mixed grazing systems in a relatively low-cost manner.

The dynamics of mixed grazing were exactly the same in a paper presented by Tommy Boland, UCD School of Agriculture and Food Science, on mixed-species swards and their role in pasture-based sheep production systems.

Welsh experience

The concept of rotational grazing being possible no matter what type of enterprise or scale of enterprise is present was rubber-stamped by Welsh guest speaker Neil Perkins, who along with his wife Linda and family runs a flock of 2,500 ewes on Dinas Island in southwest Wales.

The farm extends to 600 acres (243ha), with two-thirds of this land classified as productive and the remainder a mixture of woodlands, coastal areas or rough grazing that contributes very little to the system.

Neil described the farm as having the potential for early grazing, but with shallow soils and exposed swards, the farm is at risk of burning off heavy covers in spring, if weather and wind direction and speed are unfavourable. At the same time there is a risk of burning up in a dry summer. Neil adds that the heavy clay nature of soil that is present limits the potential for grazing late in the year or out-wintering ewes.

The production system has therefore developed to exploit the farm’s resources of producing high quantities of dry matter during the main grazing season. Neil says there is as much emphasis placed on grass measuring and budgeting as there is on data recording in the sheep flock.

“We have focused on grassland for the last 10 years. We are now producing 30% more grass from the same area – that’s the same as having an extra 120 acres of land. It has come at a cost of £15,000 (€18,987) to set up the farm for rotational grazing but it is giving a return of £12,000 (€15,190) per year so it has more than paid for itself.”

This has been achieved in the main through close attention to soil fertility, reseeding with high-sugar grasses and mixed species such as red and white clover, plantain and chicory that have the potential for delivering high dry matter production and utilising rotational grazing to the maximum effect.

The rotational grazing system is interesting. Fields on the farm are laid out in 24- to 25-acre divisions and every field is run in its own rotational grazing system. This system is achieved by having one main fence which splits the field in half.

In spring, ewes and lambs are set stocked for a couple of weeks and as growth normally rises, each area is transformed into a rotational grazing system with six paddocks.

Square or rectangular fields are further divided into three parts in the same manner as spokes on the wheel of a bike with electric fencing, with animals tightened to one segment to begin rotational grazing.

“As soon as grass starts growing, we put ewes into one half. We then start subdividing which basically involves putting up 12 kilometres of electric fencing. Demand in each area is running on average at about 25kg DM/ha per day. Once growth hits 44kg to 45kg DM/ha, we drop out one paddock and when we hit over 60kg DM/ha we drop out another.

“We don’t want to have too many of these areas taken out as surpluses and we also have what we call a flying mob of ewes and lambs. This is basically a large group of ewes and lambs which we bring in and can graze down the area in one to two days and then move on. It keeps quality right and reduces the area taken out for haylage.”

Neil delivered a take-home message that is relevant no matter what enterprise is being run.

“You don’t have to go as technical as we did. If you can split a field in half and grow 10% more grass then the farm will be in a better position. This is the way we have gone and it’s only after we have achieved this that we move on and go to the next level”.

Examples of how paddocks are split will be detailed in next week’s sheep pages.

There is massive potential on Irish livestock farms to increase the volume of grass grown and utilised. This was the view of Micheál O’Leary, Teagasc Moorepark, in his presentation explaining PastureBase Ireland, Teagasc’s web-based grassland management tool, in operation since 2013.

There has been a steady upward trend in the number of farmers using the system over the last year to 18 months, with this growing database of information starting to return valuable insights.

Micheál showed that from drystock farms measuring regularly in 2015, there was a range in the volume of grass dry matter (DM) produced from 9.1t DM/ha to 14.7t DM/ha.

From surveys carried out, he says it quickly came to light that the farmers growing the most grass were those getting the basics right in terms of soil fertility and pH, walking paddocks regularly and taking proactive management steps and installing more paddocks to facilitate an improved rotational grazing system.

Breaking up the year into three periods of spring (1 January to 10 April), summer (11 April to 10 August) and winter (11 August to 31 December), he also showed that grass growth varies greatly in spring with a range of 0.5t DM/ha to 1.7t DM/ha. This accounts for 8% of yearly growth in a typical year, with 61% in summer and 31% in autumn.

While on the topic, Micheál described 2016 to date being far from the typical year, with grass growth running 40% behind previous years’ levels.

The drivers behind early spring grass growth were summarised into six areas as follows:

1Early closing: A balance needs to be achieved between extending the grazing season and closing a sufficient percentage of ground from October onwards to safeguard the potential for early grazing. “Every week delay in closing from 2 October reduces spring grass supply by 77kg DM/ha.”

2Closing cover: Farms with higher growth rates had a higher average closing cover, putting the farms in a strong position to capitalise on early grazing.

3Winter growth: This, according to Micheál, is influenced 50% by weather and 50% by the farmer. “If you close at too low of covers, ground will be more exposed and more at risk to poor weather which in turn will translate into lower winter growth.”

4Spring N application: The application date of spring nitrogen will have a big bearing on grass growth. This will also be influenced by the fertility status of the soil to stimulate a response and the composition of the sward (new perennial rye grass swards respond quicker).

5Spring grass management: Getting stock out early, if possible, will get covers grazed off quicker and grass growing quicker. “Farms that had stock out early and finished the first grazing rotation by 10 April grew 200kg DM/ha more spring grass and 1.1t more annual grass in 2015 (12.2t v 11.1t).

6Grass growth: Micheál says this is influenced 50% by weather and 50% by the farmer through management practices listed above.

Improving summer growth

A lot of drystock and sheep farmers are not getting enough grazing out of their paddocks, according to Micheál.

“Large fields are not producing as stock are in there too long. This affects quality and liveweight gain and also limits the volume of grass grown (grazing regrowths). Looking at PastureBase, farms who achieved seven to eight grazings from paddocks grew 12t DM/ha to 13t DM/ha in these areas. There is also likely to be a nitrogen interaction but it shows what can be done compared to set stocking with two grazings per season only delivering about 5t DM/ha to 6t DM/ha. An extra grazing on dairy farms delivers 1,385kg DM more grass. On sheep farms it could deliver up to 1t DM/ha more worth in the region of €265/t.

Take-home messages

The importance of increasing the number of paddocks and operating a rotational grazing system was highlighted as a key take-home message.

“Paddocks don’t need a massive investment to get a rotation going. The difference in a mid-season enterprise is very easy to see, even if you have three to four paddocks, compared to set stocking”.

Applying sufficient nitrogen for the stocking rate on the farm is also another important consideration. However, Micheál cautioned farmers in this area.

“There is no point spreading 200kg nitrogen over the year if your fertility is incorrect. 90% of soil samples are not at the optimum for soil fertility so the key is to start with lime and improve the pH”.

The final message delivered is that without measurement you cannot accurately identify how the farm is performing and where changes need to be made.

“I’d advise anyone interested in driving grass production to think about using PastureBase. It is free to farmers and is easy to access as long as you have access to a web connection.”