ABSTRACT Higher stocking rates of lambing ewes have been associated with poorer ewe-lamb behaviour and lamb survival. This study tested the hypothesis that increasing the mob size and stocking rate of lambing ewes on commercial farms will reduce the survival of their lambs. Data were collected from 66 producers in Australia for Experiment one and 22 producers in New Zealand for Experiment two. Survival of single- and twin-born lambs decreased by 1.4% and 3.5% per extra 100 ewes in the mob, regardless of breed, in Experiment one. The survival of Merino lambs in Experiment two decreased by 0.9% per extra 100 ewes in the mob, regardless of birth type. Increasing stocking rate by 1 ewe/ha also decreased lamb survival by 0.7% in Experiment one. However, this was not evident in Experiment two. These findings highlight the scope to optimise ewe mob size and stocking rate at lambing to improve lamb survival.

中文翻译：

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来自商业绵羊生产商的数据表明，在较大的群体中以较高的放养率产羔会降低羔羊的存活率

摘要 产羔母羊较高的放养率与较差的母羊羔行为和羔羊存活率有关。这项研究检验了这样一个假设，即在商业农场增加产羔母羊的群体规模和放养率会降低其羔羊的存活率。实验一的数据来自澳大利亚的 66 家生产商，实验二的数据来自新西兰的 22 家生产商。在实验一中，无论品种如何，暴民中每增加 100 头母羊，单胎和双胎羔羊的存活率分别降低 1.4% 和 3.5%。在实验二中，无论出生类型如何，群体中每增加 100 头母羊，美利奴羊羔的存活率就会降低 0.9%。在实验一中，增加 1 只母羊/公顷的放养率也会使羔羊的存活率降低 0.7%。然而，这在实验二中并不明显。