Community Regulation n. 2092/1999 decrees that ruminants in organic farms must have access to pasture at least for one productive stage in their lifecycle. In feeding and pasturing, account must be taken of the genetic features of milk animals (capacity to adapt to local conditions, vitality and resistance to disease, productive potential) and also of the fact that in some areas pastures are not easy to reach, owing to climate and terrain characteristics. According to organic farming rules, at least 60% of the dry matter is to consist of fodder - a percentage often higher than that adopted for milk ruminants rations. A more careful comparison between the productive and metabolic aspects of indigenous and cosmopolitan breeds fills a gap in scientific and technical knowledge; moreover, it is a highly interesting issue in the framework of organic farming, since the sector rules express a clear preference for indigenous breeds. The adoption of indigenous breeds ensures a better adaptation of the animals to organic farming methods and helps to enhance and differentiate the organic product from a qualitative point of view, thanks to the peculiar features of the milk of some breeds in terms of composition, nutritional and technological characteristics. Owing to the high costs of production, organic products need a careful qualitative characterization and a clear traceability, in order to meet the expectations both of the consumer and of the commercial sector. Hence the need to demonstrate that organic products derive from a farming system which is respectful of animal welfare and have qualitative characteristics which differ from those of conventional farming.