Beef steer production from two local breeds under two management systems differing in the utilisation of mountain pastures

Steer meat production is insufficient to meet market demand in northern Spain. This study aimed to compare steer production from two local beef breeds, Asturian Valley (AV) and Asturian Mountain (AM), and two management strategies, differing in yearling steers grazing summer mountain pastures (M treatment) or lowland grasslands (L treatment). A total of 83 calves born in winter-spring were studied during four whole life-cycles. During their first year of life, calves were managed with their dams on summer pastures and weaned when returned to lowlands. Once castrated, half of the yearlings of each breed were randomly assigned to treatment M or L. After summer grazing, all steers were managed at lowlands until they were slaughtered at an age of approximately 33 months after a finishing period of 3-4 months with maize silage and concentrate diet. In general, bodyweight gains were greater in AV than in AM breed, resulting in greater slaughter (714 versus 616 kg) and carcase weights. During the second summer season, AM steers gained more bodyweight than AV in summer pastures, resulting in a breed x management interaction. In the next periods (autumn grazing, winter and spring grazing), M steers showed a compensatory growth counterbalancing their previous lower performance, whereas no differences between treatments or breeds were found in the finishing period. As a result, no differences between managements were observed in final bodyweight at slaughter or carcase weight. Summer pastures offer opportunities to manage yearling steers without adversely affecting saleable product yields.