Sreenan J M, Diskin M G
Vet Rec. 1983 May 28;112(22):517-21. doi: 10.1136/vr.112.22.517.
For the cow, fertilisation rates are generally reported to be close to 90 per cent while average calving rates fall within the range of 50 to 60 per cent. Thus, embryonic and fetal deaths account for about 75 per cent of all reproductive wastage, following a single breeding. Early embryonic death (within 20 days of fertilisation) would seem to account for about 75 to 80 per cent of all embryonic and fetal deaths and results in a substantial loss in production. The literature relating to some possible genetic and environmental causes of embryo death is briefly reviewed. The relationship between progesterone level and the initiation and maintenance of pregnancy is discussed and some data are presented.
对于奶牛，通常报道的受精率接近90%，而平均产犊率在50%至60%的范围内。因此，在单次配种后，胚胎和胎儿死亡约占所有繁殖损失的75%。早期胚胎死亡（受精后20天内）似乎占所有胚胎和胎儿死亡的75%至80%，并导致大量生产损失。本文简要回顾了有关胚胎死亡一些可能的遗传和环境原因的文献。讨论了孕酮水平与妊娠开始和维持之间的关系，并给出了一些数据。
