The benefits of a spring rotation planner for beef cattle

Grazed grass is the cheapest form of nutrition for beef cattle, and it will almost certainly outperform even the highest-quality silage in terms of daily liveweight gain in growing animals.

Exceptional rainfall in November 2022 forced cattle to be housed early, resulting in heavy grass covers ahead of spring grazing.

To avoid loss of nutritional quality, the earlier the turnout, the better, says Martina Harrington, dry stock specialist at the Irish research body Teagasc.

Although turnout date will be different for each farm, depending on soil type and rainfall, Ms Harrington suggests many farmers are overly cautious when it comes to turning out stock.

See also: How to set up electric fencing to optimise grazing

“Farmers can nearly always go a week or two earlier than they think,” she says. “If cattle are only marking the ground slightly, that is OK.”

But if grazing is causing damage, this is counterproductive, as it will affect regrowth and will slow grass growth slightly. And if the same piece of land is damaged later in the year, losses of up to 40% in annual growth are likely.

Ms Harrington has advised on using a spring rotation planner (SRP) to plan the first grazing rotation and ensure grass is grazed early enough to allow time for regrowth for the second rotation.

Martina Harrington (on left) © Teagasc

Why use a spring rotation planner?

Without employing an SPR, there is a risk of grass running out before the start of the second rotation.

Once the areas available to graze are known, enough cattle must be turned out to ensure this area is grazed on schedule.

Farmers should not worry about the silage they have left – it can be fed next winter or, based on the experience of the past few years, it may be needed in the summer during our now common mini-droughts.

Silage is expensive to make and, in 2023, it is predicted to be as expensive as in 2022. Therefore, there is good justification for leaving as much of it in the pit or bale as possible by getting cattle back to grass.

Grazing targets

The SRP is based on target areas and dates. With a turnout date and targets established, it can be used to work out how much land needs to be grazed daily, weekly and monthly and the number of stock needed to achieve this.

The key grazing targets for drier farms are:

• 30% of the farm to be grazed by 1 March
• 60% by mid-March
• 100% by ‘magic day’ – the day that grass supply matches grass demand. For most farms, this is usually between 1 and 10 April.

Farms with heavier and wetter land should expect their targets to be seven to 14 days behind these dates.

Demand for grass

Grass demand also needs to be considered. For instance, demand is likely to be much lower in dairy calf-to-beef systems than for suckler beef.

When a farm has low demand with, for example, a stocking rate that delivers 100-120kg N/ha in organic manure, silage ground should be grazed last in the autumn, before applying fertiliser in late February or early March.

Silage should then be cut in the first week of May. This will produce excellent quality silage and reduce the area to be grazed in the spring or early summer.

With a reduced area to graze, the spring and early summer grass can be managed with a much heavier stocking density, making management easier.

The farm can adopt the same spring rotation planner as a more highly stocked farm and most, if not all, of the ground is back in the rotation for late June.

The farm should then have more of a buffer if there are drought conditions in July and August.

Turnout tips

• Aim for a gradual turnout of different stock classes to each graze a specific area within a set timeframe.
• Turning out earlier with a small group stimulates the grass to grow after the winter break. The longer it has to grow, the greater the cover and the earlier the second rotation can start.
• Bulling heifers are a good first group to turn out because it gets them gaining weight and settled on the grass diet, and it should mean that they bull more easily.
• These should be followed by the lighter stock, building up to the heaviest animals.
• However, flexibility can be introduced to this rule for drier farms that may want to turn out cows and calves earlier to relieve pressure on calving sheds and reduce the spread of scours and other diseases. This can be done providing no damage is being caused to pasture.

Making silage

While the main focus is on grazing grass, it is important not to overlook the requirement for producing top-quality silage to maximise weight gain at housing and minimise the need for purchased feed.

To achieve this, aim to cut silage in mid-May, after the field has been grazed to remove dead material from the base. Silage ground should be closed by 1 April at the latest, to give six weeks of growth by 15 May.

This must be planned, but a general rule of thumb is for a farm to have started grazing its silage ground by mid-March.

Falling behind or ahead of targets

For farms that fall behind their targets, more stock can be let out or lighter covers can be grazed until they are back on track.

In a situation where farmers are ahead of targets, they should graze the heaviest covers first, rehouse some stock, supplement grass with hay, silage or meal, or consider whether the silage ground can be grazed for a second time.

Even the best plans can be thrown off course by wet weather, so have a strategy for that situation, too.

Use temporary roads to move cattle, avoid moving back over grazing ground and back-fence to avoid excessive damage. If damage is too severe, rehouse.