A comparison of growth, carcass traits, and tissue composition of 'Segurena' lambs raised either in extensive or intensive production systems

摘要

The aim of this study was to determine the performance of lambs of a Segurena local breed for growth, carcass traits and tissue composition when raised either in an extensive or an intensive production system to produce carcasses of 11 kg. In the extensive system lambs (n = 21) were raised on pasture with salt-tolerant forages (bermudagrass hybrid and ryegrass Westerwold) and were unweaned. In the intensive system lambs (n = 24) were weaned at 45 days and reared in stalls with concentrate feeding. Extensive lambs, especially twins, showed lower growth rates during the total growing period. Male extensive lambs had higher proportions of full digestive tract and stomachs and lower commercial dressing percentages. Extensive lambs had a lower percentage of valuable body parts such as liver and tenderloin. In addition they showed a higher percentage of head, shoulder and neck; and poorer conformation scores. Furthermore, their carcasses had a higher percentage of bone and a lower percentage of muscle. Nevertheless, other aspects should be taken into account, such as meat quality and meat production cost, animal welfare and taking advantage of high salinity soil and water to grow these forages. An alternative system in which grazing is supplemented with concentrates should be evaluated in future research.