Does the effect of selection history influence vegetation and plant preferences by cattle?

摘要

In this project plant and vegetation preferences of two Norwegian dairy cattle breeds with different selection history were studied. The Norwegian dairy breed Blacksided Trender and Nordland Cattle (STN) has never been selected efficiently for highermilk production. The other breed, however, the Norwegian Red (NR), has mainly been selected for this. Two herds, both consisting of STN and NR cows, were studied. To examine the animals' plant preferences, faeces samples were collected and analysed for plant fragments. Vegetation maps were also used to find possible differences in grazing preferences. Breed differences, with regard to recorded plant fragments in the faeces samples, were significant for Nardus stricta, a species characteristic of nutrient-poor but mostly species-rich vegetation types in the studied areas; these vegetation types of high importance for biodiversity especially in one of the areas. STN had the highest share of Nardus stricta. The results of the study indicate that a higherproducing cattle breed might prefer to graze more nutrient-rich vegetation areas compared to a lower yielding cattle breed, when grazing less-nutrient and base-rich, but species-rich, grasslands.