PDF(Pubmed)
Abstract：
The contribution of abortions to the overall mortality of lambs born to maiden (primiparous) ewes in Australia remains unclear. This cohort study aimed to quantify abortion and lamb mortality for ewe lambs and maiden Merino two-tooth ewes. Lamb mortality from pregnancy scanning to marking were determined for 19 ewe lamb and 11 Merino two-tooth ewe flocks across southern Australia. Average lamb mortality from scanning to marking was 35.8% (range 14.3-71.1%) for the ewe lambs and 29.4% (range 19.7-52.7%) for the two-tooth ewes. Mid-pregnancy abortion was detected in 5.7% of ewes (range 0-50%) in the ewe lamb flocks and 0.9% of ewes (range 0-4.4%) in the two-tooth ewe flocks. Mid-pregnancy abortion affecting ≥2% of ewes was observed in 6/19 ewe lamb flocks and 2/11 two-tooth ewe flocks. Lamb mortality from birth to marking represented the greatest contributor to foetal and lamb mortality after scanning, but mid-pregnancy abortion was an important contributor to lamb mortality in some ewe lamb flocks. Variability between the flocks indicates scope to improve the overall reproductive performance for maiden ewes by reducing foetal and lamb losses. Addressing mid-pregnancy abortion may improve the reproductive performance in some flocks.
摘要：
堕胎对澳大利亚少女（初产）母羊出生的羔羊的总体死亡率的贡献尚不清楚。这项队列研究旨在量化母羊和梅里诺两牙母羊的流产和羔羊死亡率。从怀孕扫描到标记的羔羊死亡率确定了整个澳大利亚南部的19只母羊羔羊和11只美利诺两牙母羊群。母羊从扫描到标记的平均羔羊死亡率为35.8％（范围为14.3-71.1％），两齿母羊为29.4％（范围为19.7-52.7％）。在母羊羊群中检测到5.7％的母羊（范围为0-50％）和两牙母羊羊群中检测到0.9％的母羊（范围为0-4.4％）。在6/19母羊羊群和2/11两牙母羊羊群中观察到影响母羊≥2％的妊娠中期流产。从出生到标记的羔羊死亡率是扫描后胎儿和羔羊死亡率的最大贡献者，但是在一些母羊羊群中，怀孕中期流产是导致羔羊死亡的重要原因。羊群之间的差异表明可以通过减少胎儿和羔羊的损失来改善母羊的整体繁殖性能。解决中期妊娠流产可能会改善某些羊群的生殖性能。
