8 June 2001

Healthy way to raise value

Securing against future downturns in milk prices is

important for producers, whether it is done through

advertising or processing and marketing milk for niche

markets. This special, edited by Jessica Buss, takes a look

at some successful processing businesses and progress in

generic advertising. Richard Allison kicks off with a look at

research into producing healthier milk

PRODUCING healthier milk by implementing simple changes to the ration may offer a way of increasing product value after the foot-and-mouth crisis.

Milk and dairy products are often perceived as being bad for human health. But a number of beneficial compounds have been discovered in milk which may allow new market niches for specialised dairy products to be developed.

Research at Teagascs Dairy Production Research Centre, Co Cork, has investigated a number of ways to increase levels of these compounds.

One such compound is oleic fatty acid, which reduces blood cholesterol levels reducing the risk of heart disease. It is normally associated with olive oil in healthy Mediterranean-style diets, according to Teagascs John Murphy.

"Oleic fatty acid in milk is doubled by including 1.6kg a cow of crushed whole oilseed rape in grass silage-based diets. A smaller increase is found when 3.2kg a cow whole soyabeans are fed instead.

"Whole rape was mixed with sugar beet pulp, as its high oil content would gum up the mill. We tried feeding whole rape without crushing, but only half the effect in milk was observed. Whole soya was fed in the form of toasted whole soyabeans and is quite palatable." When fresh grass replaced grass silage, milk oleic acid was increased much further, accounting for 43% of total butterfat. This is more than 2.3 times higher than the level observed with a standard grass silage-based diet. "This improved milk was achieved with an additional feed cost of 2-2.5p/litre," says Dr Murphy.

An additional benefit with this milk is that 34% of fat is solid at 10C, which means that the butter produced is spreadable when taken straight from the fridge. "We started developing this 10 years ago but got into problems with the logistics of collecting and processing quite small amounts of milk," says Dr Murphy. "It is ideal for small farmer-based processors, but interest has been low."

Another beneficial compound in milk is conjugated linoleic acid (CLA), which has received considerable interest. This is because it has anti-cancer properties and an anti-obesity effect, which effectively lowers risks of heart disease.

"CLA concentration in milk varies throughout the year from 6-16mg/g butterfat. This mainly reflects the amount of grazed grass in the diet. Grass appears to raise CLA production. The challenge for researchers is to maintain similar high levels during the winter housing period with silage-based diets," adds Dr Murphy.

"One strategy tested was to replace a proportion of grass silage with a mixture of molassed sugar beet pulp and brewers grains. Brewers grains contain unsaturated oils.

"This was found to increase milk CLA by 56%, but this is small compared with the much larger effect when replacing silage with fresh grass. Levels of 5-8mg/g butterfat were seen indoors compared with 15-16mg/g butterfat at grazing. We managed to achieve levels as high as 23mg/g butterfat when supplementing grazing with crushed rape."

Another factor investigated was the influence of breed. Differences were small with Irish Holstein-Friesians averaging 17.5mg/g butterfat compared with 18.5mg/g for Montbeliardes and 16.4mg/g for Normandes," says Dr Murphy.

"But variability between cows within a breed was large, ranging from 5 to 35mg/g butterfat. Selecting cows which naturally produce higher CLA milk could be another option, with herds of high CLA producing cows."

Butyric acid is another beneficial compound, as it can offer benefits on breast and colon cancers. In Ireland, milk butyric acid contents are highest in March and April and lowest in September. Dr Murphy believes that the opportunity to increase butyric acid in milk by changing the diet is limited, as it is produced in the mammary gland.

"The greatest challenge with producing healthier milk is marketing. The problem is what do you put on the carton to explain what CLA is and what claims can you make. Milk has received much unfair bashing, there is after all nothing unhealthy about it." &#42

HEALTHIER MILK

&#8226 Easily achieved.

&#8226 Benefits for human health.

&#8226 Marketing essential.