All agree that this should be less than 5 percent. Most place an expected abortion rate at about 1 to 2 percent. Most fetal losses are unnoticed and undiagnosed. These occurrences involve only one cow and are not investigated. They are likely some physiological disturbance not brought on by external disease agents and are of no consequence to others in the herd.
Records are essential.
Besides recording when pasture exposed or artificially inseminated, written histories record when pregnancy examinations were made. Records of the timing and incidence of signs of estrus are valuable in determining the reproductive history. Gestational age when evidence of fetal loss is detected is important. Anything in this regard should be recorded at the time observed. Memories fade, and items perceived as unrelated are forgotten.