Refshauge G, Golledge M, Rickard J, de Graaf S
New South Wales Department of Primary Industries and Regional Development, Cowra Agricultural Research and Advisory Station, Cowra, NSW, 2794, Australia.
Faculty of Science, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW, 2006, Australia.
Sci Rep. 2024 Aug 1;14(1):17781. doi: 10.1038/s41598-024-67847-4.
After decades of decline, the Australian sheep flock aspires to rebuild its population of breeding ewes. A successful, rebuild will rely on high pregnancy rates and number of lambs born and reared. To examine this potential, a cross-sectional study of historical ultrasound pregnancy scanning records was undertaken using records collated from two experienced sheep pregnancy scanning businesses (years 2006 to 2019) from 15,397 mobs of ewes, totalling 7,443,314 ewes. Client details were de-identified and excluded from analyses, but details describing the mobs were retained when available, such as season of mating, production zone, ewe age, and breed. The key finding was a mean pregnancy rate (ewes pregnant per ewe scanned) of 0.76 ± 0.24, with a median of 0.83. Mobs scanned to identify fetal number had a higher mean (0.84 ± 0.15) and median (0.89) pregnancy rate. The mean reproduction rate (fetuses per ewe scanned) was 1.21 ± 0.27 and the median was 1.25. Differences were observed between the factors including age, breed, season, year or production zone but all results were lower than anticipated. The unexpected findings imply a problem exists with the fertility of many Australian sheep flocks.
经过数十年的减少后，澳大利亚的绵羊群渴望重建其繁殖母羊的数量。一次成功的重建将依赖于高妊娠率以及出生和饲养的羔羊数量。为了研究这种潜力，利用从两家经验丰富的绵羊妊娠扫描企业（2006年至2019年）整理的记录，对15397群母羊（总计7443314只母羊）的历史超声妊娠扫描记录进行了一项横断面研究。客户详细信息经过去识别处理并被排除在分析之外，但在可用时保留了描述羊群的详细信息，例如配种季节、生产区域、母羊年龄和品种。关键发现是平均妊娠率（每只接受扫描的母羊中怀孕的母羊数）为0.76±0.24，中位数为0.83。为确定胎儿数量而进行扫描的羊群平均妊娠率更高（0.84±0.15），中位数为0.89。平均繁殖率（每只接受扫描的母羊中的胎儿数）为1.21±0.27，中位数为1.25。在年龄、品种、季节、年份或生产区域等因素之间观察到了差异，但所有结果均低于预期。这些意外发现表明许多澳大利亚绵羊群的繁殖力存在问题。
