International symposium on milk quality

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Milk and milk products are the mainstay of our nutrition. The demand for dairy products and the price consumers are willing to pay depend on the reputation of the milk’s quality. Here, we are talking about quality as both nutritional quality and sensory qualities such as milk flavour and odour.

As part of the process of improving milk quality, these issues were thoroughly discussed at the 5th Skjervold Symposium, which was held on 26 and 27 October in Oslo. The Symposium was jointly organized by the Department of Animal and Aquacultural Sciences at UMB and the Nordic Association of Agricultural Scientists (NJF).

The speakers at the symposium were among the leading experts in the field. A total of 19 lectures and 11 posters were presented. These covered a broad scope of topics, however, the main focus was on how to utilize breeding and feeding to improve milk quality. The issues that were discussed included fatty acid composition, vitamin and mineral contents, milk flavour and odour, as well as processing suitability. The content of the fatty acids considered to be specifically beneficial for human health can to a certain degree be “managed” via feeding strategies; primarily by controlling the amount and composition of feed fats. Grazing gives a “healthier” milk fat than traditional indoor feeding with conserved feed. Clover (especially red clover) is more favourable than the commonly grown grass species. Fat contents and fat composition also vary in different feed concentrates, which thus also have different effects on milk fat composition. It is therefore important to select appropriate concentrate mixtures in order to obtain the desired effect on milk fat composition.

Raised levels of unsaturated fats in milk can, under certain feeding conditions, increase the risk of oxidation and off-flavour. An important topic for future research will thus be the prevention of such off-flavour. Supplements of especially selenium and vitamin E, but also of carotenoids (vitamin A), presumably play a major role, since they prevent oxidation. In this connection, there should be some focus on grazing, since cows on pasture give milk with higher levels of vitamins E and A than cows fed indoors with conserved roughage. A higher content of these vitamins is also beneficial with regard to the milk’s nutritional value for humans. However, pastures generally have low contents of such micronutrients as selenium and iodine. To ensure high levels of these elements in the milk, they must therefore be given as feed supplements.

The symposium ended with a discussion about the demands consumers and the food industry will place on milk quality in the future. The issues were presented from the perspectives of a researcher and the Nordic food industry. Consumers will eventually emphasize other criteria in addition to today’s demands for high hygienic quality and good flavour and odour characteristics. Of such additional criteria, the nutritional quality of milk will play a major role. The demand for healthy food will increase, and there will be growing focus on product diversity. It was underlined that consumers will increasingly emphasize special product qualities, such as specific flavours or nutritional qualities linked to production site and method. Examples of such products include milk produced by cows that spend lots of time on pasture in general, or milk even entirely produced on traditional mountain dairy farms. An important task will be the documentation of such special qualities. Increasing consumer awareness will also lead to a focus on natural, sustainable production methods and animal health and welfare issues (ethical production).

The dairy sector is undergoing rapid technological developments. The use of milking robots and TMR feeds is rapidly gaining ground. This development presents several challenges, especially regarding milk flavour qualities. For example, it has been shown that the contents of free fatty acids in milk and the risk of off-flavour are higher in a milking-robot setup than in traditional milking systems.

Updated: 14.05.09
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