Effect of student transrectal palpation on early pregnancy loss in dairy cattle

摘要

Transrectal palpation of the reproductive tract is themost common method for pregnancy determinationin cattle and is considered a veterinary skill that newveterinary medicine (DVM) graduates should performproficiently. However, using privately owned cattle totrain students can be difficult because producers maybelieve that transrectal palpation by inexperienced studentsincreases the risk of pregnancy wastage comparedwith examination by an experienced clinician. We useda randomized field trial of 1,216 healthy Holstein andJersey cattle in 2 commercial dairy herds to estimatethe effect of veterinary student transrectal palpationon early pregnancy loss. All cattle were determined tobe pregnant using transrectal ultrasonography at approximately37 d after artificial insemination. Cattlewere then allocated into 2 groups based upon their eartag number (study group = 598; control group = 618).Cattle in the study group were immediately palpatedafter ultrasonography by a fourth-year veterinary student,whereas control cattle were not subject to anyadditional pregnancy assessment. For analysis, thestudent palpators were divided into 2 groups: studentswho had previously had formal palpation training viaan elective bovine palpation class (n = 30) and studentswho had not had palpation training (n = 134).All cattle were reevaluated using transrectal ultrasonographyapproximately 70 d after artificial insemination.A total of 53 (4.36%) animals lost their pregnancybetween the first and second pregnancy assessments. Ofthe animals that lost their pregnancy, 26 (4.35%) werestudy group cows and 27 (4.37%) were control cows. Ofthe 26 cows documented to have had pregnancy losswithin the study group, 20 out of 378 (5.3%) had beenpalpated by students who had not taken the palpationelective and 6 out of 220 (2.7%) had been palpated bystudents who had completed the elective. We found nodifference in pregnancy loss between student-palpatedand clinician-ultrasounded cattle, supporting the safetyof using privately owned animals for student bovinepalpation and pregnancy diagnosis training without affectingearly pregnancy loss.