A robust platform for production of milk in Norway by improved nutritional quality and competitiveness

TINE has fulfilled its palm oil policy and no longer use palm oil in the products. TINE want to change the fatty acid composition of milk to more nutritional desired fatty acids. This includes reduced content of palmitic acid (C16: 0) and increased content of for example Oleic acid (C18: 1). It was conducted a literature study (Activity 2) to get an overview of treatment options for protecting the fat through the rumen, i.e. protected against bio-hydrogenation. Some of the methods were evaluated. Initially tests were carried out with different concentrates added different fat sources in the form of Calcium (Ca) salts of fatty acids. The experiments were conducted both at UMB Ås with 16 cows and at Stamsædgården Klepp (FKF) with 30 cows. A significant reduction in milk yield of approximately 2 kg were recorded for the concentrates with low content of C16. This means that such concentrates is not desirable to use before we manage to protect these fat sources through the rumen. A selection of the most interesting concentrates were also tested in trials (Activity 3) with fistulated cows to measure pH in the rumen during testing of the various concentrates. In addition, the goal of the experiment with fistulated cows are studying the degree of bio-hydrogenation of various fatty acids in the rumen. The experiment is an important part of the work of a PhD student associated with the project, but not financed by the project. The experiment was carried out as a cyclic changeover design in which a total of 6 different fat sources were tested. The results showed that there was no significant difference in milk yield and feed intake with the use of the various concentrates. A field trial (Activity 4) was finally conducted to look at variations in fatty acid composition with a larger number of cows fed with the most favorable concentrate products for nutritional desired fatty acid composition and fat % in milk. The field trial run over 5 months and 10 farmers participated in the field trial. All crews had 30-40 cows. Several crews showed little difference in milk yield and fat % in periods trial diets were used. Milk from the field experiment were used for test production (Activity 5) of two milk products. The results of the test productions showing no quality defects with respect to the greater degree of rancidity with increasing content of unsaturated fats. It was desirable to test milk from the field trials for several products, but TINE pilot plant was busy and this meant that it was not conducted several experiments during the project period.

During the last decades the consumption of dairy products and in particular drinking milk have decreased. The main reason is that milk and dairy products are a major source for saturated fatty acids in the human diet, and saturated fatty acids have been f ound to increase the risk of cardiovascular diseases. In milk fat, usually more than 60 % of the fatty acids are saturated. Reducing especially C16:0 and shifting the fatty acid composition towards more unsaturated fatty acids, is recommended by Norwegian food authorities. In an earlier project, Engfrisk project, between TINE, Felleskjøpet, Bioforsk and Department of Animal and Aquacultural Sciences (IHA), full fat oilseeds were added concentrates. In the project, adding oilseeds to the diet increased C1 8:1 (oleic acid) and decreased C16:0 (palmitic acid) concentration in milk fat considerably without altering milk yield or milk quality except for the fatty acid composition. The project resulted in positive interest from the involved partners. This appli cation is a continuing of this work. In the Engfrisk project, the feeding regime was homogeneous and strictly regulated, giving milk with a predictable quality. However, the quality of the home grown feeds vary considerably between regions and among farme rs. To be more flexible, there is a need to develop feeds and feeding strategies that ensures a uniform and acceptable quality of the milk independent of location and quality of the home grown feeds. The main focus in this new project will be development of methods for increasing rumen by-pass of dietary fatty acids, and improvement in our understanding of the transfer of dietary fat into milk. This is important for production of milk with a specified fatty acid composition under various conditions. In ad dition, alternative feed ingredients will be evaluated with respect to influence on milk fatty acid composition. An important issue is the amount of feed ingredient needed to yield a wanted quality of the milk.