Bovine Abortion and Embryo Loss Study Guide

Overview and Clinical Importance

Bovine abortion and embryo loss represent significant causes of reproductive failure and economic loss in both dairy and beef cattle operations. The diagnostic success rate for determining the cause of bovine abortion ranges from only 25-45%, making this a challenging area of veterinary medicine.

Pregnancy loss in cattle can be categorized by timing: early embryonic death (conception to day 42), late embryonic/early fetal death (days 42-60), and fetal abortion (day 60 to term). Normal abortion rates should be less than 3-5% annually; rates exceeding this threshold warrant investigation.

Early Embryonic Death

Early embryonic death (EED) accounts for the majority of reproductive loss in cattle, occurring primarily before day 16 post-breeding (before maternal recognition of pregnancy). Fertilization rates in cattle typically exceed 90%, but only 50-60% of inseminations result in confirmed pregnancies at day 30.