Earlier this year, the Gibson family from Penrith took the prestigious championship award in the Cumbria Grassland Society grass silage competition with their 2018 crop. We visited Castlesteads Farms to find out how they made the best for their dairy cows and their digester.
When you are feeding silage to 400 milking dairy cows and their followers, and into a 250 kilowatt anaerobic digester, nothing can be left to chance. Any mistake will not only be seen in the health and performance of the cows, but it will also be reflected in the biogas output in the AD plant – something which can vary widely in both quantity and composition with different quality feedstocks.
That’s why the Gibson family from Plumpton, near Penrith in Cumbria say that when they made some substantial changes to their silage-making system in 2018, they did everything ‘by the book’.
“We wanted to be sure we did everything exactly as we should,” explains John Gibson, who farms with his father, James, brothers, Richard and Chris and general farm worker, Graeme McAleese. “It was our first year of doing it this way and we didn’t want any comeback.”
The basics on Castlesteads Farms had been done well for many years. The family prides itself on producing high quality forage and John recalls how his father had won the Cumbria Grassland silage competition back in the 1980s.
So, it was with particular pleasure that Mr Gibson senior watched the success of the next generation, as they repeated the feat by taking the same championship this January, for their silage made in 2018.
“It’s all about the team,” insists John, who says that by undertaking every silage-making process with the farm’s own workforce, the operation can be carried out exactly when and how they like.
So, what do the Gibsons say are the key ingredients to making successful silage, and what were the changes which made the difference in 2018?
Many of the processes were exactly the same as usual, according to John, whose family dedicate over 600 of the farm’s 750 acres to growing and conserving grass.
The silage was cut, as usual, using four mowers in two front-and-back combinations. Cutting would never start before 11am, and the crop is turned within six to 18 hours with a 15-metre tedder, covering roughly 25-30 acres/hour.
“We pick up the following night after 24-36 hours and the last of the crop will come in on day three,” says John.
With a self-propelled Claas 860 forager, around 500 acres are taken in the first cut, usually on around 21 May.
It was in the choice of additive that the first change was made in 2018, following a problem experienced the previous year.
“We had used a bacterial inoculant in 2017 and although it seemed to stabilise the forage we had a problem with the clamp collapsing,” says John. “It turned out that the inoculant preserved the silage but the chemical reaction created water.”
The upshot was that the silage was slippery and the clamps collapsed at feed-out, leading to untidy faces and significant waste.
However, the family had read about the efficacy of the preservative, Safesil, which worked in a different way from either inoculants or acids. They decided to contact Kelvin Cave to see if the product could meet their needs.
“Dad has always believed in acids for silage and we felt Safesil was the next step,” says John. “We liked the fact that its ingredients are used in human food preservation and we felt it would have the benefits of the acid but without the handling issues.”
The family used Safesil for the first time in 2018 and adhered to the recommended application rates to the letter.
“We prefer to be on the higher side than not use enough and we particularly wanted to do everything by the book in the first year,” said John.
He also switched between Safesil Challenge for the wetter silage to Safesil Pro as the dry matters increased.
Michael Carpenter, Kelvin Cave’s northern area manager, explains: “The two Safesil products each contain the same three key ingredients, but they are included in different proportions in the two products, to address different situations.
“In wetter silages there’s a higher risk of poor fermentation due to spoilage bacteria and for this we would usually recommend Safesil Challenge,” he says. “This contains a higher proportion of sodium nitrite which works by killing harmful bacteria.
“However, where dry matters are higher, the risks to the silage can be slightly different, and it is more likely to suffer aerobic spoilage through the activity of yeasts and moulds.
“So, where dry matter is higher we would tend to recommend Safesil Pro which contains a higher proportion of the other two ingredients – sodium benzoate and potassium sorbate – which eliminate the activity of yeasts and moulds,” he says.
Switching to Safesil for their 2018 silage was just the first of two major changes and several further minor adjustments which were made by the Gibsons.
The other major difference was the use of a SilaPactor to give better consolidation at the clamp.
“We knew we wanted a SilaPactor and tried to buy one from a local farmer,” says John’s brother, Richard. “But he said it was ‘the best thing on the farm after me’, so we had no chance, and had to find one somewhere else!”
Eventually acquiring a 3m machine, the brothers opted to build the clamp in layers, rather than in a wedge.
“Michael [Carpenter] had told us we would fit a third more silage in a clamp by using the SilaPactor,” says John. “I have to say I was sceptical, but by the time we had finished silaging, I genuinely thought we must have missed some fields as we’d compacted it into so much less space.”
Side sheeting was done with the usual care but again, using a slightly different method.
“We used a 6m side-sheet for a 4m wall, putting around 12 inches under the silage,” says John. “We bought some KlampClips from Kelvin Cave which clipped the side sheets to the wall while we were filling the clamp.
“I have to say they were bloody brilliant, and cut a four-hour job down to an hour,” he says.
Other changes included switching to ClampFilm, which is sucked down into the silage and forms an air-tight seal, under the top sheeting.
“We also found you don’t put your foot through it, and we used it on every clamp this year and will use it again,” he says.
The team also used Warner’s Corners on some of the clamps, named after Kelvin Cave’s veteran south western area manager, David Warner, who devised this method of folding the sheets. “Sheeting up was definitely better once we’d got our heads around the technique,” says John. “We wish we had used it on our outside clamps as it would have stopped the water going down the sides.”
Once the job was done and the clamps weighted down, the team waited six weeks before opening the forage.
“We were determined to do everything we should to make sure the product did what it said on the tin, and yes, it did what it said on the tin!” says John. “It was just like fresh green grass.”
Analyses undertaken throughout the winter have corroborated this impression, seen, for example, in a first cut with an ME of 12.1MJ/kg DM, a D value of 75.8, crude protein of 18.2%, sugars of 5.9% and intake potential almost off the scale, at 136g/kg ML (metabolic liveweight).
“Yes, feed intakes are high,” says John, who also praises the Lely Juno feed pusher for boosting them further. “And the cows are doing really well on it.”
Following this success the team has also used the same preservative and procedure for their forage maize which has been processed as shredlage.
“This has really helped with butterfats which are definitely on the up,” he says, referring to the 9,800 litre 4.3% fat and 3.3% protein herd.
Youngstock too are doing better than ever on an 18% dry matter, fourth cut silage taken on 28 October, preserved with Safesil Challenge and fed with a blend.
Only putting their feed out twice a week, he says it stays stone cold for as long as it’s needed.
“That’s unusual for this period of time,” he admits. “In the past, it would have heated up and the youngstock didn’t do so well. And you know when it heats you have lost dry matter and you’ve lost energy.”
By retaining the maximum dry matter of the high energy forage, the Gibsons have also met with increased success with their anaerobic digester.
“Along with the slurry, last year we fed in up to 11 tonnes of silage every day,” says John. “This year that has gone down to around seven and as low as five tonnes of silage per day for first cut. This not only produces just as much gas, but that gas is also of a better quality, with more methane and less carbon dioxide.
“The anaerobic digester is not so very different from a cow,” he adds. “The cows don’t just produce more fat but they also have better fertility – what price can you put on that?”