Performance of dairy cows fed an entirely organic diet containing cold-pressed rapeseed cake

Abstract

Organic dairy production will be based entirely on organically grown feeds as of 2008, and thereby a demand is created to find suitable feeds that are possible to grow locally. The aim of this experiment was to investigate whether milk yield and milk composition were maintained when cows were fed a 100% organic diet, with around 15% of dietary DM from cold-pressed organic rapeseed cake, compared to a 95% organic diet, in which a conventional protein source was used. Two experimental groups included 20 cows each and the study was carried out during two indoor periods. For cows fed the rapeseed cake diet, milk yield increased by 3.0 kg/day, but contents of milk fat and milk protein of multiparous cows decreased, resulting in similar yields of energy-corrected milk in early lactation. Milk from cows fed rapeseed cake had increased content of unsaturated fatty acids, including conjugated linoleic acid. In conclusion, it is possible to maintain milk production of dairy cows fed 100% organic feedstuffs using cold-pressed rapeseed cake as the main protein source compared to a 95% organic ration.