The 2018 grazing season will be remembered by many as one of, if not possibly the most challenging on record. The favourable growth in recent months has provided a marginal reprieve for some of these farmers’ worst affected by a late and costly spring and drought conditions in summer, while for many farmers along the western seaboard it has been a much kinder backend to date than in previous years.

This has resulted in heavier covers developing on some farms with a change in normal grazing practices required to achieve optimum grass utilisation. This was a topic of discussion at the recent Teagasc farm walks with the advice given to farmers to put a plan in place that also ensures the farm is setup to deliver sufficient grass supplies post-lambing next spring.

Speaking at the farm walk on the farm of Terence, Richard and Tim Sheil in Wexford, Michael Gottstein of Teagasc underlined the importance of doing so. A ewe grazing at present will have a dry matter (DM) intake requirement of about 1.2kg DM to 1.5kg DM with this allocation important to meet during mating and continuing into the first month of gestation. This compares to a grass dry matter demand of 2.4kg DM for a ewe suckling twin lambs at turnout and 3.5kg DM five weeks into lactation. Therefore, while grazing available grass may prolong the grazing season in the coming weeks, it will be far more beneficial and reduce labour and feed costs next spring.

Grazing heavy covers

Getting back to satisfying current demand and grazing heavy covers, Michael advises that where ewes are grazing heavy covers or swards with a high percentage of lower-quality material at the base of the sward and given free access to a large area of grazing it can have negative consequences on performance.

“If you don’t restrict the area of grazing, it will result in ewes grazing all the green material first and then being left with poorer-quality grass.

Breeding is taking place on many farms and the last thing you want is to hamper performance now in forcing them to clean off paddocks when the ram is in”.

The approach recommended to deal with heavy covers is to split the grazing area into two- to three-day blocks. In this manner, ewes will graze the green or leafy material for the first day and a half to two days and then be forced to graze down the lower-quality material for a shorter period of time. This will not have any long-term effect on performance with intake recovering when ewes enter the next grazing section.

Table 1 details the number of grazing days for a range of grass covers based on 100 ewes grazing a one-hectare plot and offered 170kg DM/day. Michael explains that at this time of year grass utilisation is likely to be in the region of 75%, meaning an allocation of 1.7kg DM/ewe is required to deliver 1.3kg DM/ewe.

Michael Gotstein advises farmers to split heavy covers into blocks or sections to improve utilisation.

Increased divisions

Where ewes are being run in smaller grazing groups, the recommendations in Table 1 can be adjusted to suit. A barrier that is often raised to splitting paddocks into smaller sections is access to water. Michael points out however that water intake is likely to be low at this time of year, particularly with rainfall forecast and the dry matter of grass reducing. “The big challenge with such a system is generally water but at this stage of the year it’s not a major barrier. Putting a few buckets of water into the paddock will gauge demand but it’s likely you’ll find that ewes will drink very little and you’ll get away with a temporary supply.”

Grass utilisation can be maximised even further by splitting paddocks into day blocks. This works particularly well with deferred grazing but may not suit all farms with a higher labour requirement in moving fences and sheep daily. Fences will also face more pressure and need to be erected solidly with a good current in the electric wire.

This is another important aspect when getting sheep accustomed to paddock grazing split with temporary electric fencing. “The first couple of days are the most important. If sheep get bad habits and end up breaking through the fence they will be much harder to stop,” says Michael. Adding an extra row of wire and keeping posts closer together initially will pay dividends where sheep have no experience with electric fencing.

With day-block grazing, ewes graze the available grass in a short period of time. If grazed during inclement weather, paddocks can become soiled or mucky quickly but generally recover in a matter of days.

Tim Sheil says they are concentrating on boundary fencing and making the farm stockproof first and using temporary electric wire to split paddocks into smaller divisions.

Targeted closing

As touched on in recent weeks the target closing pattern for an early- to mid- March lambing flock stocked at 10 ewes to 12 ewes per hectare is to have 20% of the farm closed by late October, 40% by mid-November, 60% by late November and 80% by mid-December. This will provide a rest period of 120 days and give enough time for paddocks closed first to have a cover of grass present before growth grinds to a standstill.

Teagasc researcher Philip Creighton said that a paddock closed on 20 October will under normal grass growing conditions have a cover of 900kg DM/ha to 1,000kg DM/ha available in early March or 7.5 days grazing per hectare for 50 ewes and their lambs while a sward closed in early November will deliver six grazing days per hectare.

Swards will find it difficult to develop a cover where grazed later in the year with a sward closed on 20 November delivering 3.7 grazing days per hectare while a sward closed on 20 December will deliver three grazing days.

Where closing targets are falling behind and there are a number of heavier and lighter covers available, grazing the lighter covers first can help to bring the farm back on track. This is provided that the paddocks with the lighter covers are convenient to the yard, have good shelter and are suitable for grazing earlier in the rotation next spring.

Some farmers at the events queried leaving paddocks with a good cover of grass closed for grazing next spring. The answer depends on the lambing date and condition paddocks are currently in. Where ewes are lambing earlier and there is good-quality grass down to the base of the sward this is a good option where ewes are grazing in January or February. Where covers are heavy and swards have poor-quality or dying grass at the base of the sward they are better utilised now as quality can deteriorate even further resulting in poor feeding quality next spring.