Ridler Anne L, Flay Kate J, Kenyon Paul R, Blair Hugh T, Corner-Thomas Rene A, Pettigrew Emma J
School of Veterinary Sciences, Massey University, Palmerston North 4472, New Zealand.
Department of Veterinary Clinical Sciences, City University of Hong Kong, Kowloon, Hong Kong 999077, China.
Animals (Basel). 2022 Jan 28;12(3):319. doi: 10.3390/ani12030319.
The reproductive performance of ewe hoggets is poorer than that of mature-age ewes due to production of fewer lambs with poorer survival. Scant data are available on the risk factors for, and causes of, the mortality for lambs born to ewe hoggets, the impact of ewe deaths on lamb loss, and the causes of death for lambs born to ewe hoggets vs. mature-age ewes lambing in the same circumstances. In this study, 297 lambs born to 1142 ewe hoggets were necropsied along with 273 lambs born to 1050 mature-age ewes. Low lamb birthweight, multiple litter size, and increasing ewe hogget average daily gain from breeding to late pregnancy were risk factors for lamb mortality. The most common cause of mortality for lambs born to ewe hoggets was stillbirth and the risk factors for stillbirth were similar to those for lamb mortality generally. Approximately 11% of ewe hoggets' lamb deaths were due to the death of the dam. Causes of mortality differed between lambs born to ewe hoggets vs. those born to mature-age ewes. Management practices to increase ewe hogget lambs' birthweights (particularly those from multiple litters) and supervision of ewe hoggets at lambing time are recommended.
青年母羊的繁殖性能比成年母羊差，因为其产羔数较少且羔羊成活率较低。关于青年母羊所产羔羊死亡的风险因素、原因、母羊死亡对羔羊损失的影响以及青年母羊与在相同情况下产羔的成年母羊所产羔羊的死亡原因，现有数据很少。在本研究中，对1142只青年母羊所产的297只羔羊以及1050只成年母羊所产的273只羔羊进行了尸检。羔羊出生体重低、产仔数多以及青年母羊从配种到妊娠后期平均日增重增加是羔羊死亡的风险因素。青年母羊所产羔羊死亡的最常见原因是死产，死产的风险因素通常与羔羊死亡的风险因素相似。约11%的青年母羊所产羔羊死亡是由于母羊死亡。青年母羊所产羔羊与成年母羊所产羔羊的死亡原因不同。建议采取管理措施提高青年母羊所产羔羊（特别是多胎羔羊）的出生体重，并在产羔时对青年母羊进行监督。
