Producing top quality, palatable and nutritious silage is never easy, especially when farming in Scotland’s unpredictable climate.

However, Aberdeenshire animal scientists Dr George Whitelaw and his wife Anthea, Greenmyre, Oldmeldrum, appear to have mastered the art of harvesting some of the best big bale silage by managing grass growth, sward height and ultimately quality.

No strangers to the prize rosettes at various silage events, the couple who took up farming some 20 years ago, won the North of Scotland Grassland Society big bale silage competition in 2009 and 2007 and were reserve in the same section in 2004. They’re also regular prizewinners at the Royal Northern Spring Show at Thainstone – having won first prize and third prize in the big bale section in 2008, second prize in 2005 and a first prize away back in 1993.

And, forget the belief that big bale silage always comes a poor second in nutritional value and quality to that of pit silage – the quality and palatability of big bales at Greenmyre always comes pretty close to that of clamped silage. As it is, last year’s winning bale crop harvested the second week in June at Greenmyre, yielded 26.6% dry matter with an ME of 11.1MJ/kg of dry matter, a D Value of 69, and protein and sugar levels of 137g/kg and 33g/kg respectively. The pH was 4.4, while the lactic acid content was 61.6g/kg.

“It’s all down to management and quality of the grass,” said George, who until 1990 had been an animal nutritionist at the Rowett Research Institute, Aberdeen, specialising in ruminant physiology and digestion. Anthea also spent some time at the Rowett, working on the nutrition of baby pigs, before becoming a biology teacher at Inverurie Academy.

“We try to utilise our grass fully at all times and it’s never allowed to go to full head – I don’t like it getting any longer than 6inches for grazing cattle. We always make silage early, ideally when less than 10% of the grass is in flower – I’d be really concerned if we didn’t have our silage cut by the middle of June.”

Most of the winning bale crops at Greenmyre have been made from young, two-to-four-year-old, leys based on early perennial ryegrasses and white clover, but older leys are also used when the quality is right.

“By managing the grass better and not allowing it to get too long, the sown grasses and clovers persist and the sward can remain sweet for many years. Our highest ever D-value silage (72%), which won the North of Scotland competition in 2007, came from a nine-year-old ley and had an ME of 11.6 and protein of 14.8. That’s all down to good sward management,” he said.

With only 52 acres on this low-ground farm, the couple look to make 14-20 acres of silage for their 16 suckler cows and 40 commercial ewe flock.

The majority of calves are finished off grass after a winter indoors on silage and home-grown cereals. Texel cross lambs are also finished off grass and these are sold privately as freezer-ready lamb to a wide range of loyal customers. In recent years two or three prime Limousin cross animals have also been sold as boxed beef and have met a steady demand.

“We’ve been selling lamb like this for the past 10 years and it’s extremely satisfying,” said Anthea, who attends to most of the sheep work and instigated the move into direct marketing.

“We lamb outside in early May and the majority of lambs are away by the end of September off grass. Texel cross lambs out of Scotch Half-bred ewes work really well for this because they kill out well and our customers like them because they are low in fat,” she said, adding that all lambs are killed at Mathers, Inverurie and cut up and packed by a local butcher.

Achieving a reputation for producing top quality beef and lamb is reliant on feeding some of the best home-grown forages available and that’s where the couple believe that harvesting the best silage possible reaps rewards.

George added: “We always try to grow top quality silage to keep feed costs down and save on expensive proteins. Our cattle are wintered on only 3lb/day of home-grown barley and ad-lib silage and finished on grass while the sheep are fed silage and blocks during the winter. The ewes come indoors early February to ensure there is an early bite for the lambs and calves”.

The first artificial fertiliser for the silage fields is normally applied at the beginning of April at a rate of 100kg/ac of 25:5:5, with another 50-75kg spread four weeks later. Most years, the couple also take a smaller second cut of silage at the end of July or beginning of August, having applied 50-75kg of a 20:10:10 fertiliser as soon as possible after the first cut.

Obviously, no slurry is available for top-dressing grass and the dung from the cattle sheds is used mainly for the arable ground, where 13 acres of spring barley is grown, for feed or high-N malting samples.

All silage work is done by local contractors, with the aim being to wilt the grass for 48 hours before harvesting with a chopper-baler. Amazingly however, last year’s winning crop was rained on twice before being spread out, then baled in the late evening, some 90 hours after cutting – and wrapped next morning, again in torrential rain. Bales are ‘double-wrapped’ (21 turns) then stacked three high on a hard standing surface.

No vermin control measures are necessary as to date there has never been any problem from rats, birds, or mice.

It just goes to show that even the smaller livestock units, wholly reliant on contractors, can make superior quality silage and produce an economic output from cattle and sheep enterprises. But as Dr Whitelaw points out “with contractors’ charges for silage operations now up to £10 per bale it is more important than ever that what is inside the bale is of the highest possible quality.”