Monthly variations of milk composition with special regard to fatty acids depending on season and farm management systems ‐ Conventional versus ecological

During one year's period bulk milk samples were collected monthly from three different types of farms: 1. conventional farming, indoor feeding with silages throughout the year. 2. conventional farming, grazing during summer season, 3. ecological farming, grazing during summer season. The milk protein, fat and ash contents were significantly lower in ecologically kept dairy cows. The highest percentage of saturated fatty acids was found in the indoor group, whereas the trans fatty acid and linolenic acid contents were significantly higher in the ecological group. Dairy products are major sources of conjugated linoleic acid (anticarcinogens). There were enormous differences between the indoor group (0.34%) and the ecological group (0.80%). During the year, the most impressive variations were registered for the cholesterol‐raising palmitic acid. The benefits for the consumer: low content of cholesterol‐raising fatty acids, high content of cholesterol‐lowering fatty acids and high percentage of anticarcinogenic fatty acids, cannot be realized by one system of farm management.