Seasonal variation in nutrition and supplementation in extensive sheep systems in north-central Spain

8 pages, 5 tables, 5 figures.-- Contributed to: proceeding of a workshop held in Aberdeen, Scotland (March 5-6, 1998).Extensive systems of sheep production predominate in the hill and mountain areas of Europe. A typical example is that fourd in northent Spain. In these areas seasonal variation in herbage production has a large influence on the way in which sheep management systems have developed and are managed. Milking sheep, especially of the Churra breed, graze pasture in early summer and then forage on stubbles in late summer and are supplemented with hay and/or concentrates in winter, during pregnancy and lactation. Merino sheep, kept for meat production, utilise mountain pastures in summer and are brought down to lowland areas for autumn, winter and spring, in a transhumance system. These breeds are adapted to the different systems and show differences in theiír foraging behaviour which allow them to make best use of the forage resources. Supplementation during times of feed shortage, especially during pregnancy and lactation, is essential in order to maintain high levels of animal performance, but it also ensures that the welfare of the sheep is not compromised since it prevents the nutrient intake and body condition of the animals becoming too low.Peer reviewe