School of Agriculture and Food, The University of Melbourne, Parkville, VIC 3010, Australia.
School of Agriculture and Food, The University of Melbourne, Parkville, VIC 3010, Australia; Faculty of Biological Sciences, The University of Leeds, Leeds LS2 9JT, United Kingdom.
Meat Sci. 2021 Nov;181:108581. doi: 10.1016/j.meatsci.2021.108581. Epub 2021 May 29.
The present study investigated the impact of heat stress and genetics on lamb growth performance and meat quality. Forty-eight Dorper and 2nd cross [Poll Dorset × (Border Leicester × Merino)] lambs (38--42 kg; 4-5 months old) were allocated to either thermoneutral [TN; 18-21 °C, 45-55% relative humidity (RH)], or heat stress (HS; 28 °C-38 °C, 40-60% RH) conditions in a 2 × 2 factorial design for 2 weeks. Compared with 2nd cross, Dorper lambs had a lower respiration rate (RR) and rectal temperature (RT), and exhibited less decline in body weight under HS. 2nd cross lambs showed a higher body weight gain than Dorpers under TN conditions. HS increased a* and chroma of the Longissimus thoracis et lumborum (LTL) from 2nd cross lambs over 10 days of display, but had no impact on Dorper LTL. In conclusion, Dorpers showed higher heat tolerance compared with 2nd cross lambs during the 2 weeks HS.
本研究调查了热应激和遗传对羔羊生长性能和肉质的影响。将 48 只杜泊羊和 2 代杂交羊[（皮特兰×（边区莱斯特羊×美利奴羊）]（38-42kg；4-5 月龄）按 2×2 析因设计分配到适温（TN；18-21°C，45-55%相对湿度（RH））或热应激（HS；28-38°C，40-60%RH）条件下，处理 2 周。与 2 代杂交羊相比，杜泊羊的呼吸率（RR）和直肠温度（RT）较低，在 HS 下体重下降较少。在 TN 条件下，2 代杂交羊的体重比杜泊羊增加。HS 增加了 2 代杂交羊的背最长肌（LTL）的 a*和色值，持续 10 天，但对杜泊羊的 LTL 没有影响。总之，在 2 周的 HS 期间，杜泊羊比 2 代杂交羊表现出更高的耐热性。
