Upping quantity does not equal better returns

More milk means more money – but only if the input justifies the output.

That’s the opinion of dairy nutritionists and consultants who urge milk producers pushing for the “extra litre” to ensure their cows and their management systems are geared up for it.

Volac nutritionist Richard Kirkland says it’s the response in milk production to an additional unit of feed that’s the determining factor of whether it is worth pushing for higher yields.


“When the value of the milk is worth more than the additional feed needed to achieve it, then there’s an economic benefit in terms of milk sales to increasing feed level – in other words, the “marginal litre”,” he says. (See Table 1 and 2)

When the value of the extra litre is more than its marginal cost then it’s worth pursuing, agrees Peter Thorne, DairyCo’s MilkBench manager.

“But the difficult bit is actually getting a reliable assessment of that. Dairy farmers must have a good handle on inputs and outputs and the level of their efficiency. Good record keeping and maintaining a robust analysis of the efficiency of input use with a system such as Dairy Co’s Milkbench benchmarking service is the key.”

He says the biggest losers who chase extra litres are those trying to push yield too far to cover rising costs. “Good use of feed is essential. The most striking figure to illustrate this is that unsuccessful intensive milk producers are, on average, spending 1p/litre more on feed and getting 800 litres less milk a cow a year. That’s a very telling piece of data.”

And it’s important to remember that pushing cows for increased production mustn’t be considered in isolation from the total production system. Cow health and fertility should not be compromised as a consequence, adds Dr Kirkland.

The latest figures from DairyCo show average UK milk yield increased by 331 litres a cow during the last year to reach 7,406 litres. It’s a larger increase than in recent years and clearly indicates dairy farmers are chasing higher production targets.

And with an average milk price of 26.65p/litre in April 2011 – 2.51p/litre higher than 2010 – there has been an increasing incentive for milk producers to lift yields.

Cow response

“Cows fed to meet their requirements for maintenance and milk production for the level of milk produced today will show a variation in their response to additional feed offered tomorrow.

“And this response depends on how cows are able to ‘partition’ the additional energy in the diet between milk production and body reserves, which will influence their body condition score,” says Dr Kirkland.

How cows respond to additional feeding to lift yield is directly linked to several factors:

1 Genetic potential/breed of the cows

The efficiency of milk production is similar between cows, but high genetic merit cows will give a greater milk yield response than lower genetic merit cows or non-Holstein-Friesian breeds.

High genetic merit cows are genetically “programmed” to partition nutrients to milk production, while lower genetic merit animals will partition more to body condition and so reduce the milk yield response.

2 Body condition score

Cows need to achieve a specific level of body condition score post-calving, which requires additional nutrients if the cow has a low body condition score at the outset.

3 Stage of lactation and milk yield

Cows in early lactation giving high yields will produce a greater milk response to additional feed than lower-yielding cows in later lactation.

Dr Kirkland believes pushing for extra milk doesn’t simply mean feeding more of the cheapest ingredient in an attempt to maximise returns.


“Diet factors influencing the yield response include the type or composition of additional feed and nutrients. High-starch diets may increase milk volume, but it will be at the expense of milk fat in the early stage of lactation. Higher-starch diets fed to cows in later lactation can encourage cows to lay down body fat rather than produce more milk.

“High-fibre supplements have less effect on milk volume, but favour milk fat, while proven high-fat supplements will promote milk yield and yield of milk solids.”

Dr Kirkland says cows use fat more efficiently than other ingredients for increasing milk production.

“Metabolisable energy (ME) of typical dairy diets is used with 62-65% efficiency for milk production, compared to fat, which is used with more than 80% efficiency. The farm’s milk contract may therefore influence the most appropriate type of feed offered to achieve particular objectives based on what is being paid for.”

But milk producers can also make some valuable assessments as they deliberate over the pros and cons of pushing for the extra litre.

Are your cows already eating as much as they can? If the only way to bolster yield is to increase energy intakes, then a rumen-protected fat will enable cows to consume more energy with each bite.

Are you achieving the maximum benefit from home-produced forages and have silages been analysed to evaluate the energy being provided? Always be aware of changes in energy levels when new silage pits are opened. If energy levels are higher in a new pit it may not be necessary to make diet modifications; if lower the response to additional feed will be reduced.

Cow health

“Opting for increased production shouldn’t compromise fertility,” says Dr Kirkland. “Additional energy can support fertility and increasing the energy supplied from fat will provide not just energy for milk production, but will improve levels of the pregnancy hormone progesterone and the quality of ovulated eggs.”

And cows suffering from acidosis caused by feeding high starch rations won’t respond as well to increased feed rates because of their poor rumen function.

“When cows are already ‘on the edge’ in terms of rumen acidosis, pushing for higher production can be risky unless diet changes are carefully scrutinised. The aim should be to improve the fibre and starch balance or to include fat to increase the energy density of the diet without adding to the acid load in the rumen.

“Farmers only feeding cake in the parlour may already be near the maximum safe levels of feeding so increasing feed levels may not be advisable.”


Table 1: Performance and margin response to increased concentrate fed

Yield/cow (litres) Low

5,500 Average

7,000 High

8,000 Very high


Milk value/cow (£) (24.4p/standard litre) 1,347 1,717 1,960 2,205

Conc costs (£) (£165/t) 248 330 429 536

Margin over milk and conc (£) (MOC) 1,100 1,385 1,531 1,669

Source: John Nix Farm Management Pocketbook 2011

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Case study: Paul and Coral Richards

Tresemple Farm, Truro

Paul and Coral Richards run a 180-cow herd at Tresemple Farm, Truro. Land and labour are the unit’s limiting factors so the aim is to maximise yield per cow to maintain profitability.

The herd has an average yield of 11,042 litres at 3.98% butterfat and 3.17% protein – and produces 4128litres from forage.

“Attention to detail is paramount and that includes genetics and forage quality. We want high quality grazed grass and grass and maize silage to maintain rumen health,” says Paul.

Emphasis is placed on achieving a high energy density in the diet and protein quality from concentrates in order to maximise the space in the rumen for home grown forage.

The basic ration fed throughout lactation comprises grass, grass and maize silage, brewers grains plus a blend (£300/t) at 2kg/cow/day. The blend provides quality proteins and sources of digestible fibre as well as 10% rumen protected fat. The herd is also fed a proprietary parlour concentrate.

“While the blend is more expensive than standard concentrates, it’s extremely energy dense and with the response achieved it works out at 6.39p/l which we feel is a very competitive figure,” says Mr Richards.

Table 2

Case study: Philip Stansfield

Knowle Farm, Upton Cross

Philip Stansfield runs a 200-cow herd averaging 8,000 litres at 4.2% butterfat and 3.4% protein at Knowle Farm, Upton Cross, Liskeard.

Last year, with the objective of producing quality milk with high protein percentage to fully exploit a cheese-making contract and achieve a premium milk price, he felt pushing for the extra litre was worthwhile – but not at the expense of milk protein.

The herd’s production goals are now focused towards healthy cows, milk solids and finally yield based on a partial TMR diet fed all year round with a selective in-parlour feeding system.

The diet was re-formulated to include high-quality protein sources such as prairie meal together with bypass starch in the form of crimped maize and rumen-protected fat to maintain energy supplies. The ingredients were introduced to a high-quality forage ration of grass and maize silage and fodder beet.

“The cost of concentrate a litre has increased, along with the feed rate but this has been more than recovered in the increased milk price based on the higher protein levels,” says Mr Stansfield, who ensures cows are receiving sufficient nutrients by body condition scoring each month.

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