Sandals W C, Curtis R A, Cote J F, Martin S W
Can Vet J. 1979 May;20(5):131-5.
A study of the computer stored records of 293 dairy cows and 652 calvings reveals the effects of retained placenta and metritis complex on reproductive performance. The overall incidence rate of retained placenta was 11.2%. Retained placenta was 4.6 times more likely to occur following twin births than following single births. Most cases of retained placenta occurred during the fall. Forty-five percent of that seasonal increase was explained by an increased number of calvings. Metritis complex was diagnosed following 54.8% of retained placenta cases. Retained placenta alone did not significantly impair reproductive performance. Metritis complex, in the presence or absence of retained placenta, caused a significant (P</=0.05) increase in days open, services per conception, calving to first heat intervals and days from calving to first service. There is an indication (interaction P</=0.1) that cows with both retained placenta and metritis complex are more severely affected than cows with either retained placenta or metritis complex alone. The influence of retained placenta on fertility appears to depend on the proportion of cows with retained placenta that have metritis complex.
一项对293头奶牛和652次产犊的计算机存储记录的研究揭示了胎盘滞留和子宫炎综合征对繁殖性能的影响。胎盘滞留的总体发病率为11.2%。双胎分娩后发生胎盘滞留的可能性是单胎分娩后的4.6倍。大多数胎盘滞留病例发生在秋季。该季节性增加的45%可由产犊数量增加来解释。54.8%的胎盘滞留病例随后被诊断为子宫炎综合征。单独的胎盘滞留并未显著损害繁殖性能。无论有无胎盘滞留，子宫炎综合征都会导致空怀天数、每次受孕配种次数、产犊至首次发情间隔以及产犊至首次配种天数显著（P≤0.05）增加。有迹象表明（交互作用P≤0.1），同时患有胎盘滞留和子宫炎综合征的奶牛比单独患有胎盘滞留或子宫炎综合征的奶牛受影响更严重。胎盘滞留对繁殖力的影响似乎取决于患有胎盘滞留且伴有子宫炎综合征的奶牛比例。
