LEAF Linking Landscape, Environment, Agriculture and Food, Instituto Superior de Agronomia, University of Lisbon, Lisbon, Portugal.
CIISA - Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, University of Lisbon, Lisbon, Portugal.
J Anim Physiol Anim Nutr (Berl). 2019 Sep;103(5):1295-1302. doi: 10.1111/jpn.13148. Epub 2019 Jun 27.
Seasonal weight loss (SWL) is a major constraint in extensive animal production systems in the tropics and Mediterranean. The objective of this study was to characterize the amino acid profile of muscle and hepatic tissues of Australian Merino, Damara and Dorper lambs under restricted feeding to evaluate the impact of SWL at the metabolic and physiological levels. SWL induced generalized muscle protein breakdown among restricted groups of all breeds, with varying intensity. Dorper breed mobilized less muscle amino acids when under these conditions, with the Damara having frequent significant differences, namely by having lower amino acid concentrations in the muscle of restricted lambs. Damara lambs showed greater ability to catabolize branched-chain amino acids in the muscle tissue, which indicates yet another mechanism that provides the Damara with the necessary tools to endure harsh conditions. Overall, the Damara breed mobilized more muscle amino acids than the other breeds, with a better capacity to catabolize branched-chain amino acids in the muscle, while maintaining muscle structural integrity.
季节性体重减轻（SWL）是热带和地中海地区广泛动物生产系统的主要限制因素。本研究的目的是描述在限制饲养下澳大利亚美利奴羊、达马和杜泊羔羊肌肉和肝组织的氨基酸谱，以评估 SWL 在代谢和生理水平上的影响。SWL 诱导所有品种限制组的普遍肌肉蛋白质分解，强度不同。在这些条件下，杜泊品种动员的肌肉氨基酸较少，而达马品种经常出现显著差异，即限制羔羊的肌肉中氨基酸浓度较低。达马羔羊在肌肉组织中具有更强的分解支链氨基酸的能力，这表明达马提供了必要的工具来忍受恶劣条件的另一种机制。总体而言，达马品种动员的肌肉氨基酸多于其他品种，具有更好的分解肌肉中支链氨基酸的能力，同时保持肌肉结构完整性。
