Unlocking the potential of grazed grass

When setting up the farm to achieve more from grazed grass, the principles are the same, irrespective of enterprise, with a higher number of paddocks and rotational or paddock grazing having the potential to improve grass quality while also increasing the volume of grass grown. In a sheep grazing situation, the recommendation is five to six paddocks per grazing group.

Farmlets in the Athenry demo flocks are laid out with five grazing divisions per group. These range in size from 1.5ha to 2.5ha, depending on the stocking rate of 10 ewes, 12 ewes and 14 ewes per hectare for the 60-ewe flocks.

While there are five permanent divisions, it is normal practice for these paddocks to be temporarily split during the main grazing season to manage grass quality better.

It is not always straightforward in sheep enterprises to operate a paddock grazing system due to land fragmentation. However, on many farms there is potential to reduce large field sizes, either permanently or temporarily, to manage grass better during peak growth periods.

The optimum, similar to all cattle enterprises, is to graze an area in a short time frame of three to four days to a week or, in a set stocking system, divide large areas that are grazed at a low stocking rate so that fresh grass is on offer every week, ideally, to two weeks.

Fencing is critical

The secret to operating a paddock grazing system with sheep is to have good fencing. This is critical to be able to confine sheep to certain areas; for example, having dry ewes graze out paddocks later in the year.

There is a significant cost differential between the type of fence erected. Table 1 details the costs of a range of fencing types on a per-metre basis and also a rough cost for 100m of fencing.

It should be noted that while there is a significant differential in price of permanent fences, there is also a marked difference in the quality of the fence and its expected lifetime, with PDM posts traded with a 15-year guarantee. Concrete post fences and the new Clipex fence also offer a longer lifespan.

Fences are calculated on the cost of materials excluding VAT, with posts spaced at 4m and a strainer post at both ends. With temporary grazing, roll-out fences are more expensive but greatly reduce labour.

Creep grazing delivers 2kg

Research has shown creep grazing lambs ahead of ewes has the potential to increase average weaning weights by 2kg liveweight. Offering lambs a supply of high-quality grass can deliver similar levels of performance to creep feeding.

The greatest limitation is having adjoining fields or paddocks that allow lambs to graze ahead of ewes. Good fencing is also required for the practice to work.

A number of companies are manufacturing creep gates costing in the region of €80 to €150, depending on the length of the gate. Some field gate manufacturers also have specialised gates that incorporate a creep section in the centre of the gate.

Creep grazing can be used successfully with creep feeding or supplementation of lambs, as it allows lambs to be fed in troughs and minimises excessive costs associated with ad-lib creep feeding during the main grazing season.

Meal levels can be reduced, or ideally cut out, where lambs have access to high-quality grass and reintroduced if grass supplies diminish or quality reduces.

High performance with mixed grazing

While there has been an increase in paddock grazing in suckler or beef enterprises, mixed paddock grazing has been slower to take off, with many farmers pointing to a higher cost of splitting paddocks.

Experience on mixed farms in the Teagasc/Irish Farmers Journal BETTER farm Beef Programme or the Teagasc BETTER farm Sheep Programme have shown cattle and sheep can be rotationally grazed satisfactorily with temporary fencing.

The last photo in Table 1 shows a fence erected on the farm of Charlie Crawford, Co Donegal. Charlie has divided large fields by using a combination of a number of timber stakes (to add stability) and insulated steel pigtail posts or plastic posts.

The fence works best with a timber post at each end, with a number of intermediate timber posts recommended every 50m in longer fences. Many farmers prefer pigtail posts to plastic/PVC posts, citing lower lifespans.

Plastic insulators/joiners can be used to erect two rows of polywire at a lower level, with a row of steel wire on top. This has worked well on the programme farms. The potential benefits of mixed grazing are a 7% to 8% increase in stocking rate and a 10% lift in animal performance.