How to replace concentrates and get more milk from forage
MAG/Shirley Macmillan Dairy farms clamping grass silage with digestibility of more than 70% should have the courage to challenge their production of milk from forage.
Substituting 1kg of concentrates with 1kg of top-quality forage is no longer just about saving feed costs, but about reducing a herd’s environmental impact and improving business sustainability too.
See also: Why cutting concentrates is key to more milk from forage
Factors affecting milk from forage
- Healthy soil for optimum crop growth – more than 80% of Wynnstay soil tests showed suboptimal pH
- Seed selection to suit a farm’s geography and geology
- Multicut silage system for higher quality
- Diet balanced to encourage higher forage intakes
- Parlour software to be calibrated and accurate
- Mixer wagon accuracy for mixing and feeding
- Frequency of push-ups, sufficient feed space and water
- Cow health status, particularly lameness
Source: David Howard, Wynnstay
Forage
“Feed and fertiliser are the two biggest factors affecting a carbon footprint.
“Your cheapest feed is home grown and it also has the lowest carbon footprint; anything that arrives in a lorry increases it,” says nutritionist David Howard, Wynnstay’s head of dairy services.
He points out that a herd increasing its annual output from forage by 1,000 litres a cow is saving the equivalent in concentrates of 460kg. At a basic 30p/kg, this is worth £138 a cow.
“Grazed grass averages 3.3p/litre, with 7.5p/litre for quality first-cut silage and parlour concentrates at 14.8p/litre.
“Maximising forage use – and reducing the reliance on purchased feed – is important from a profitability and sustainability point of view, particularly as feed accounts for 40-60% of total production cost,” he says.
Despite improvements in forage production, ration formulation and feeding methods, David thinks the industry is “conservative on challenging forage”.
Forty percent of respondents in Farmers Weekly‘s recent Sustainable dairy survey What makes a sustainable dairy farm – survey results said they were producing 3,000-3,999 litres from forage.
However, David Howard cites Kingshay figures to March 2024, which show the average milk from forage at 2,691 litres a cow, with the top 10% of herds achieving 4,371 litres.
“We produce fantastic high D [digestibility]-value, 12 ME [metabolisable energy] silage, so why is this not translating to more milk from forage?
“[We] need to have the confidence to remove 1kg of concentrate and replace it with 1kg of forage. A Holstein herd averaging 9,000 litres should be able to get 4,000 litres from forage,” he argues.
Herd performance
One key factor that reduces output from forage is selecting for milk yield, because it results in cows getting larger, says David.
The simple calculation used for this KPI assumes that forage covers cow maintenance, he explains.
This effectively reduces the litres produced from grazed grass and silage.
“Twenty years ago, the typical Holstein was 650kg; now they are 750kg or more. Bigger cows eat more as a percentage of their bodyweight,” he points out.
© Tim Scrivener
To challenge herd performance from forage, David suggests working with the farm’s advisers to identify a specific bottleneck (see “Factors affecting milk from forage”).
“Could it be old grass leys? The higher the D-value, the higher the forage intakes. If silage is below 70 D-value, it’s important to check soils, seeds, and grass species,” he says.
Herds with good-quality forage should next look at their feeding accuracy, systems and cow groups.
Balancing the whole diet correctly encourages higher forage intakes, as does combining two or more forage types in a mix.
“Forage-to-concentrate ratio is also important, at 60% forage and 40% concentrate,” says David.
Nutrition software
Feed-rationing software, utilised to its best, is essential for efficient feeding, so parlour software should be calibrated monthly to fine-tune accuracy, he says.
And instead of operating cow management groups based on yield, he would like to see more herds with a first-lactation group plus a mature milking group as a way to optimise intake efficiency and genetic potential.
Management basics such as mixing times, feed space and water access are all equally important influencers of intakes.
“Big Holstein cows need 75cm of feed space and 10cm water space as these impact DM [dry matter] intake,” he adds.
The dairy farmer
Nigel Harper © MAG/ Shirley Macmillan
Farm facts
The Dairy Farm, Holmes Chapel, Cheshire
- 375 Holsteins
- Calving year-round with an autumn bias
- Grazing May to September according to weather
- Farming 166ha including: 20ha grazing for late-lactation cows plus heifers; 73ha maize; 73ha grass silage
Improving silage quality, together with reducing concentrate inputs, has helped lift milk from forage to 4,196 litres in one of Cheshire silage contractor Nigel Harper’s dairy herds.
The 320 Holsteins based at The Dairy Farm, Holmes Chapel, average 10,522 litres at 4.03% fat and 3.31% protein from 3.133t of concentrates.
“In our first year, yield was 9,500 litres and milk from forage 3,600 litres,” says Nigel, who reckons being able to drop concentrates by 500kg a cow saved him £150 a cow a year.
“Yet he thinks there is no single answer to improving output from home-grown forages.
“There is no magic thing: a lot of different factors affect milk from forage, starting with the soil, and cow health is huge.
“Clamp management, feeding, herd health and genetics are as important as making top-quality silage,” he says.
Crop husbandry
Crop quality has improved through a good reseeding programme (leys are renewed every five years) and selecting better varieties.
“Land management is a big factor: soil testing, pH and trace elements. Our pH was too acidic for maize, so we limed quite a bit.
“Some fields had had too much slurry and were high in P and K and we had to ease back on applications.”
Nigel operates a multicut system for grass silage starting in the first week of May, cutting every five weeks to get metabolisable energy at 12 MJ/kg dry matter (DM). He says silage DM is key.
“We average 32%; if it’s too wet, it’s acidic; too dry and cows won’t eat it.”
Attention to detail includes in-cab harvest technology to determine chop length according to grass DM, and techniques such as leaving a stubble of 6-7cm to avoid soil contamination at pick-up.
“This leaves the bottom leaf on the plant so we get quick regrowth, and also it’s good to sit the cut grass on – it helps wilting.”
Clamp management
Compacting silage evenly in the clamp has eliminated waste, while different cuts are layered within clamps to try and produce consistency at feed-out.
It takes four days to get across a grass silage face with a shear grab; a block cutter is used in summer – mainly on the maize as it has a bigger face – and this avoids spoilage caused by air ingress.
Both silages are fed once a day in the total mixed ration. This is pushed up six or seven times because cows eat from fibreglass floors and soon nose the mix out of reach.
Staff use a feeding app and a timer to ensure that mixing in the 22cu m tub mixer is an optimum five minutes.
“We have four different people feeding and this keeps operators sharp, precise and consistent. It’s consistency all the time for the cow,” says Nigel.
“We are now looking more at genetics with genomic testing, as I feel we can do everything pre-cow as good as we can.
“We are breeding a smaller animal for better feed conversion and less in maintenance,” he adds.
The researcher
Output of milk from forage from UK dairy farms has not kept pace with rising milk yields over the past 40 years, according to researcher Prof Liam Sinclair of Harper Adams University.
“Yield has increased by around 100kg a cow a year, but this has nearly all come from concentrates and makes the UK dairy industry much more vulnerable to world commodity prices,” he says.
If this rate continues, today’s national average yield of about 8,000kg a cow will rise to 9,000kg, and he believes the aim should be for more than 5,000 litres of this to come from forage.
However, Liam (who also teaches a post-graduate diploma in ruminant nutrition) points out that the calculation method for yield from forage is not precise.
“If you have 5% refusals, then you are overestimating how much concentrate the cows have been fed. The quantity of refusals not fed to the milking cows should therefore be considered,” he explains.
“Also, a TMR [total mixed ration] provides a fixed ratio of forage to concentrate, and the cow does not have the opportunity to increase forage intake without also increasing concentrate intake, so you need to challenge the cow to eat more forage when formulating the ration.”
Concentrate ratio
Ironically, forage quality is less important in high-yielding herds, he adds.
This is because when feeding a 50:50 forage-to-concentrate ratio, with 50% of the forage as grass silage and 50% maize, then only 25% of the ration is grass.
In this scenario, quality is very important, but not critical, he explains.
By contrast, “if you are feeding an 80:20 forage-to-concentrate ratio, with just grass silage as the forage, then the quality of the grass silage is critical”.
While avoiding waste feed is important, Liam says cows must be fed ad-lib, otherwise performance is reduced, particularly for susceptible animals such as lame cows or first-lactation heifers.
And feed must be available to cows when they want to eat. This requires good feed fence design, enough push-ups to ensure feed is not out of reach, and sufficient feed space.
“We found in a survey that the mean feed face provision was 56cm a cow, with some herds as low as 30cm; also, some herds were only pushing the feed up once a day, which may well reduce intake and performance,” he adds.
Yield a hectare
Liam suggests a better indicator of forage utilisation would be milk yield from forage a hectare.
However, with less fertiliser being used – thanks to an increasing reliance on legumes for nitrogen – he thinks such yields may be lower.
“Data from recorded herds would suggest only around 5,000 to 6,000 litres/ha, and we should be well over 10,000 litres/ha,” he says.
He suggests the current focus on feed efficiency may result in cows eating less forage.
“We want cows to use their feed efficiently, but we also want them to eat a lot of forage and get more yield from the least expensive element of the ration, which is less subject to world trade prices.
“Unless undertaken correctly, and like for like is compared, then using feed conversion efficiency [kg milk divided by kg feed DM] as a target may favour feeding concentrates over forage.”
Transition Live
Sustainable livestock systems will be among the seminar topics in a packed programme at Farmers Weekly’s Transition Live on Thursday 8 May in Leeds.
Speakers at the one-day event include farmers, researchers, policy leaders and industry specialists, among them award-winning young dairy farmer Ellie Lovell.
She will share the steps she and her family are taking to boost financial and environmental sustainability in their dairy herd.
To book tickets for Transition Live, visit fwi.co.uk/transition-live