The objective of this study was to identify the effect of abortion on performance of Iranian Holstein cows that calved between 2005-2014. Abortion records were categorized in two groups: 1) new abortion (NLA), and 2) rebreeding abortion (RA). Production data (305-d milk, fat, and protein yields) were analyzed using PROC MIXED, number of inseminations per lactation period (INS), postpartum health disorders (PPHD), and culling records using PROC GLIMMIX, and calving to conception records using PROC PHREG of SAS software (SAS Institute, 2013). For each separate model, main herd-cow factors and all two-way significant interactions were considered in the analyses with results being reported for each calving status by lactation period. In total, 12.5 % of lactation periods were associated with at least one case of abortion, while 1.9 % of the lactation periods commenced with an abortion. Based on results from the present study, milk production decreased for cows having abortion classified as NLA or RA. Overall, when there was a RA, there was an increase in median days non-pregnant (DNP) by 132 d and INS by 1.6, whereas cows with NLA had median DNP of 15 d less and an INS of 0.17 less than cows with normal parturitions. Compared with cows with normal parturitions, cows with a NLA were 1.24, 1.88, and 2.41 times more likely to have PPHD, and be culled from the herd for involuntary reasons and reasons related to reproduction, respectively. The results of this study indicate abortions were associated with cow health and milk production and reproductive performance, indicating losses due to abortion are not only a direct result of the loss of a pregnancy.

中文翻译：

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流产对荷斯坦奶牛产奶，健康和生殖性能的影响。

本研究的目的是确定流产对2005-2014年间产犊的伊朗荷斯坦奶牛生产性能的影响。堕胎记录分为两类：1）新流产（NLA）和2）再繁殖流产（RA）。使用PROC MIXED分析生产数据（305天的牛奶，脂肪和蛋白质的产量），每个泌乳期的受精次数（INS），产后健康失调（PPHD）和使用PROC GLIMMIX进行的剔除记录，以及使用以下方法分娩成孕记录SAS软件的PROC PHREG（SAS研究所，2013年）。对于每个单独的模型，在分析中考虑了主要的牛群-牛因子和所有双向显着相互作用，并按泌乳期报告了每个产犊状态的结果。总共有12.5％的哺乳期与至少一例流产有关，而1。哺乳期的9％从流产开始。根据本研究的结果，流产为NLA或RA的母牛的产奶量下降。总体而言，当出现RA时，未怀孕（DNP）的中位数天数增加132 d，而INS则增加1.6，而具有NLA的母牛的中位数DNP比正常的母牛少15 d，而INS减少0.17分娩。与具有正常分娩的母牛相比，具有NLA的母牛患PPHD的可能性高1.24倍，1.88倍和2.41倍，并且分别由于非自愿原因和与繁殖相关的原因而被淘汰。这项研究的结果表明流产与母牛的健康，产奶量和生殖能力有关，表明流产造成的损失不仅是流产的直接结果。