Comparison of Fetal Losses from Diagnosis of Pregnancy Using Ultrasonography or Rectal Palpation in Beef Heifers by Novice or Experienced Technicians

Pregnancy diagnosis is widely practiced in cattle production systems. Ultrasonography is an alternative technique to rectal palpation for pregnancy diagnosis. Fetal losses caused by rectal palpation are well documented; however, reported losses from ultrasonography for pregnancy diagnosis are often confounded by normal embryonic losses during early gestation. Losses caused by inexperienced technicians have been reported previously, but limited information is available on technicians that are in the learning process. Our objectives were to compare fetal losses from pregnancy diagnosis during early gestation for 1) stage of gestation at the time of diagnosis (< 53 or ≥ 53 d), 2) method of diagnosis (ultrasonography or rectal palpation), and 3) different skill levels of the technicians (novice or experienced). Beef heifers (n = 2,190) exposed to natural service for 27 d, followed by diagnosis of pregnancy between 42 and 74 d of gestation were used to evaluate these objectives. Overall loss was 1.55%. Risk of loss was greater (P < 0.01) in heifers < 53 d pregnant compared with heifers ≥ 53 d (3.46 vs. 1.26%; a 2.74-fold increase) at the time of evaluation. Greater fetal loss (P = 0.051) occurred with rectal palpation than with ultrasonography (2.68 vs. 1.29%; a 2.08-fold increase). Heifers evaluated by inexperienced technicians had a 2.07% fetal loss, whereas heifers evaluated by experienced technicians had only a 1.06% loss (P < 0.01; a 1.95-fold difference). Cattle producers and veterinarians should recognize the importance of stage of pregnancy, level of technician experience, and method of diagnosis used to reduce losses attributable to pregnancy diagnosis.