The ovine variety “Merino de los Montes Universales” and its good adaptation to traditional transhumant breeding system

The “Merino de los Montes Universales” (MMU) is a variety still involved in traditional long distance transhumance: these herds walk for 24 days to complete a 580 km journey, twice a year, between the summering province of Teruel (Aragón, Northern Spain) and Jaén (Andalucía, Southern Spain), where they spend the winter. MMU morphology is adapted to this breeding system: for instance, the mean weight is limited to 81.5 kg in rams and 56. 62 kg in ewes while they present short longitudinal diameter (83.44 cm in rams and 68.81 cm in ewes) and large height at withers (80.55 cm and 65.21 cm for rams and ewes, respectively). In all, this morphology ensures MMU ability to carry out the long walking journeys. The walking transhumance allows MMU feeding by extensive grazing throughout the year, promotes natural lactation, protects the animals from extreme temperatures, and keeps the herds in close contact with the environment. It therefore promotes an existence similar to that of wild small ruminants in the Iberian Peninsula, while not requiring high annual replacement rates (15%, compared to 16-18% in stationary flocks in the same region). It also reduces stress by avoiding mechanical transport and by making claws trimming unnecessary, since claws growth and wastage cancel each other along the year. The changes in the claws associated to the walk have been directly measured in a set of 18 ewes: even if some modifications are statistically significant in the forelimb, they are not associated to lameness or discomfort in the animals.