Kenyon Paul R, Corner-Thomas Rene A
School of Agriculture and Environment, Massey University, Private Bag 11222, Palmerston North 4410, New Zealand.
Animals (Basel). 2022 Nov 19;12(22):3207. doi: 10.3390/ani12223207.
A number of potential advantages have been identified for breeding ewe lambs at 7 to 9 months of age, including increased lifetime productivity and profitability. However, breeding at this young age in extensive pastoral systems, such as in Australasia, can be associated with a number of disadvantages resulting in uptake of this management procedure being relatively low. This review highlights the known differences between ewe lamb and mature ewe reproductive performance, thus differing in their management. The review then summaries the scientific literature of factors that affect ewe lamb reproductive success, with a focus on recent studies conducted under extensive pasture-based conditions in Australasia. In particular, this review outlines the importance of ewe lamb live weight and body condition score on their productivity. The potential long-term consequences of breeding a ewe lamb at a young age in terms of her future success and that of her offspring to weaning are briefly outlined. In addition, the potential impacts of selecting progeny born to ewe lambs as future replacement ewes are discussed. Throughout this review, optimal management guidelines from prior to breeding the ewe lambs until rebreeding at 2 years of age are provided. Lastly, areas requiring future research are identified and discussed.
人们已经确定了7至9月龄繁殖母羊羔羊的一些潜在优势,包括提高终身生产力和盈利能力。然而,在澳大利亚和新西兰等粗放的牧区系统中,在这个幼龄进行繁殖可能会带来一些不利因素,导致这种管理方法的采用率相对较低。这篇综述强调了母羊羔羊和成年母羊繁殖性能之间已知的差异,因此它们在管理上也有所不同。然后,该综述总结了影响母羊羔羊繁殖成功的因素的科学文献,重点关注最近在澳大利亚和新西兰基于粗放牧场条件下进行的研究。特别是,这篇综述概述了母羊羔羊体重和体况评分对其生产力的重要性。简要概述了幼龄繁殖母羊羔羊在其未来成功以及其后代到断奶方面的潜在长期后果。此外,还讨论了选择母羊羔羊所生后代作为未来替代母羊的潜在影响。在这篇综述中,提供了从繁殖母羊羔羊之前到2岁再次繁殖的最佳管理指南。最后,确定并讨论了需要未来研究的领域。