Herbage and milk productivity and quality when grazing different legumes and herbs

Summary

In order to evaluate how different legumes and herbs affects the quality of organic milk a grazing study was performed at the organic research station Rugballegaard with 48 dairy cows. Swards with Lucerne (Medicargo sativa), red clover (Trifolium pratense), white clover (Trifolium repens) and white clover together with chicory (Cichorium intybus), respectively, were established in 2005 together with perennial ryegrass (Lolium perenne) in two replicates. The study was carried out in 2006 over three two-weeks periods during the season. Generally, the proportion of legumes and chicory was high in the four species mixtures. Sward composition highly affected grazing behaviour. Sward height measurements indicate that the white clover mixture was eaten without much selection, the red clover was partly avoided in some areas, and in contrast lucerne seemed to be eaten selectively. In chicory swards selection occurred in a patchy way. Milk yield and protein content was unaffected by treatment. Milk urea content was clearly lowest in the milk from the cows grazing chicory.