How sheep farmers can protect spring grass covers

Grass mostly stops growing in January and early February so if sheep are not removed from fields in the autumn when swards are still active, spring grazing supply will be limited, Dr Creighton advises.

Dr Phil Creighton © Debbie James

Autumn closing dates and covers have a big influence on the ability of swards to recover and grow.

Advice

With winter grass growth of around 5kg DM/day a sward may need around 120 days to regenerate.

This may be longer for less productive fields or ones that have been over-grazed. Therefore, fields should be closed from late October onwards at a target cover of 1,200kgDM/hectare (ha).

By closing early, more grass will accumulate to give a level of cover that responds quicker when temperatures rise in the spring and will help to increase response if nitrogen is applied early.

Action

• Plan which fields to close, and when.

Dr Creighton recommends the following closing plan to provide an average farm cover of 1,800-2,000kg DM/ha at the beginning of March:

• A target for closing 100% is not included because it is often not practical to move all sheep off the grazing area.
• Spring grass availability is highest in paddocks closed in late October so these should be the first that ewes graze around lambing.
• As an example, a field closed at the end of November at 1,200 kg DM/ha (about 3cm high) and allowed to grow for 100 days when growth averages 5kg DM/ha will provide an opening cover of 1,700kg DM/ha (5-6cm) by 15 March.
• Fields closed later in the autumn may have a better recovery rate as grass growth is likely to increase during February and March – for example a field closed at 1,200kg on 30 December with the intention of grazing again on 15 April will grow at an average of 6.5kg; over 105 days this provides an opening cover of 1,882kg DM/ha.

Tips

• Close paddocks on time
• Close in order
• Do not re-graze to set up grass in the spring

It can be assumed that sheep have a daily DM intake equivalent to 2.5% of bodyweight, although this will increase if their nutrient requirement is higher, for example in lactation or for finishing lambs. Or it will be lower, as with dry ewes.

Calculating total intake and matching this to feed supply will allow farmers to plan for deficits.

Advice

AHDB senior sheep scientist Dr Liz Genever gives an example of a budget based on the flock of Ian and Rosanna Horsley, host farmers for one of the workshops. They have 169 ewes, 68 shearlings, 90 ewe lambs, 34 ram lambs and eight rams.

The daily feed intake of a single ewe weighing an average of 65kg is 1.6kg DM – 2.5% of her bodyweight. For 169 ewes that adds up to 274kg DM/day.

A shearling weighing 60kg has a daily feed demand of 1.5kg DM – totalling 102kg DM/day for 68 shearlings. Ewe lambs weigh an average of 35kg so the total daily intake for 90 is 79kg DM. The 34 ram lambs, weighing an average of 40kg, need 34kg DM/day and eight rams averaging 100kg need 20kg DM/day.

Dr Liz Genever © Debbie James

The total daily feed demand for the Horsleys’ flock is therefore 509kg DM. The flock grazes 36ha, therefore the daily demand is 14kg DM/ha.

By measuring grass weekly, having a closing plan and calculating the total feed available from conserved forage, feed deficits can be identified and action taken to supplement when it costs the least to the business.

Action

If there are gaps in the feed budget, supplement before lambing when demand is low and response is high.

Feeding silage plus concentrates costs 15p per kg DM compared with spring grass at 5p; supplementing a lactating ewe whose feed demand can be over 3% her bodyweight can cost up to 37.5p/day.

Autumn grass supply is variable across the UK, with growth continuing to struggle in drier areas such as the Midlands.

Dr Genever says some farmers in the north and Wales who benefited from the combination of rain and warm weather in September have been able to take a third cut of silage.

“Grass availability in the south-west is less than we would normally expect, with autumn availability challenging on many farms,’’ she adds.

Where grass supply is limited, decisions need to be made early so next year’s production isn’t affected, she warns.

Options to plug feed deficits

• Identify additional grazing locally – grass, cover crops or stubble turnips – but be aware there will be competition for these this year.
• Identify sources of forage extenders, such as fodder beet or waste vegetables. Compare crops based on cost/kg DM as cheap crops could contain high levels of water.
• Assess the amount of grass on farm at this point.
• Think about using more electric fencing to improve utilisation and remove stock from grazed areas to help recovery.
• Ensure that only productive stock are being taken into the winter as this will reduce overall feed demand.

Pedigree Lleyn breeders Ian and Rosanna Horsley aim to capture flock performance entirely from grass and home-grown forage, but under-performing leys in combination with a poor growing season are challenging that policy in the short term.

They started farming Baston Hall Farm near Buckley, Worcester, 12 months ago after relocating from Devon and plan to reseed half the grassland area with herbal leys.

The opportunity to reseed was missed this year because they needed to prove to Natural England that the land – in the Malvern Hills Area of Outstanding Natural Beauty – wasn’t semi-natural and secured permissions only in mid-September.

How they are reducing grazing pressure

Grass growth dipped in August and, with no grass wedge ahead, haylage was fed during August; by 1 October 45 bales had been fed.

Thinner ewes were being fed 500g/day of concentrates for the last month to achieve a body condition score (BCS) of 3-3.5 at tupping although this may change as grass availability increases and condition is gained.

To remove grazing pressure, ewe lambs won’t be tupped this year.

The Horsleys hope to off-winter sheep on a neighbouring farm and are also considering buying fodder beet to supplement haylage.

“We will use the fields we will be reseeding as sacrifice areas,’’ Mr Horsley explains.

The future

Their reseeding programme may include growing forage crops – not only for winter feed but to provide a break crop in fields with a high wire worm burden.

No concentrates were fed last year – the only form of supplementation was mineral buckets – but Mr Horsley says this affected ewe condition.

“I think we will have to supplement this year. We are in a better situation with haylage because we went into winter last year with 60 bales but this year we made 210 but there has been so little grass growth we have had to feed earlier,’’ he adds.

Farm facts

• 9.6 ewes/ha stocking rate
• Outdoor lambing from 1 April
• Synchronised breeding in shearlings to lamb two weeks ahead of the main flock
• Silt loam soil
• Pedigree members of Performance Recorded Lleyn Breeders
• Lambs that don’t make the grade for breeding are sold as stores