Dairy Event 2010: Adding value to milk
Milk quality is a top priority for any cheese maker who wants to achieve the best yield of cheese while retaining consistency of flavour, body and texture.
It explains why Milk Link, the UK’s biggest manufacturer of cheese, puts so much effort into helping its farmer members supply just what it needs to produce its many different lines.
The company turns out about 60,000t a year from five creameries across the country, including a range of Cheddars, regionals such as Red Leicester and Double Gloucester and blue veins like Stilton and Shropshire Blue.
We are looking for high protein and high fat levels in all our manufacturing milk – the more the better-provided levels are kept in balance, with protein roughly four-fifths the butterfat level, says the company’s membership manager Phil Cork. “Our pricing schedule reflects this – 85% of the value of an ex-farm litre is based around these constituents, and the higher they are, the higher the payment.”
From 1 August each per cent of protein a litre was worth 3.876p, and each per cent of butterfat 1.974p, he adds. “This provides a strong incentive for our members – another way of looking at it is that each 0.1% increase they achieve in protein will generate an extra 0.4p/litre on the milk price.”
The company has been working hard to spread the quality message, mainly through technical updates. “We explain the price benefits and how to achieve them, and the message has been well received,” says Mr Cork.
Buoyed by that success and to help improve things further, Milk Link is now focusing on protein type rather than overall amount. “Casein levels play an important role in cheese yield – other proteins remain in the whey and make no contribution,” he notes.
“Casein typically accounts for 75-85% of milk protein, and averages about 78%. The higher the level the bigger the cheese yield – it typically takes 10,000 litres of milk to make 1t of cheese, but with high-casein milk you can make the same amount with a few hundred litres less, which has obvious cost-saving potential.”
Milk Link has already started providing feedback to members by listing casein separately on the milk quality notification. The company is also informing farmers on the benefits of high casein levels, and how to achieve them.
There are several ways farmers can maximise casein production, including breeding, feeding and health, Mr Cork explains.
Breeding can be used to influence the type of casein, and could gain favour if buyers start relating payments to casein levels, he says. There are three types – A, B and E, with B showing the greatest benefits to cheese production. Selecting dairy sires with the BB gene can make a big difference – in Teagasc trials, BB milk boosted Cheddar yields by up to 8% compared with AA milk, says Mr Cork.
More immediate ways to achieve high casein levels are nutrition and health. Basing a diet on crude protein alone is not enough – feeding to increase casein means delivering the right amount and proportion of constituent amino acids to the udder via the bloodstream, he explains.
“Microbial protein has an excellent balance of amino acids, but can be deficient in amino acids like lysine, methionine and hystidine, meaning high-yielding dairy cows often struggle to get enough. The trick is to find a concentrated source of amino acids that can by-pass the rumen.”
A trial by feed manufacturer Carrs Billington on five herds in 2008 using protected soya and rape extracts boosted casein content by an average of 7.2% and cheese yield by 5.5%, he notes.
And mastitis has a bigger depressive effect on casein levels than any other factor, says Mr Cork. “Several research studies have shown it can severely decrease the proportion of casein in the total milk protein. Sub-clinical cases can go undetected so this milk tends to go into the bulk tanks for collection.”
Although the company has no plans as yet to base milk cheque values on casein levels, given their importance on cheese yields it is probably only a matter of time.
fwlivestock@rbi.co.uk