Effects of early pregnancy diagnosis by per rectal palpation of the amniotic sac on pregnancy loss in dairy cattle.

Abstract

OBJECTIVE: To determine effects of per rectal amniotic sac palpation (ASP) for pregnancy diagnosis during early gestation on pregnancy loss in lactating cows. DESIGN: Controlled, randomized block design. ANIMALS: 368 pregnant dairy cows. PROCEDURES: Pregnancy was detected via transrectal ultrasonography (TRUS) at day 29 (day of estrus = day 0), and cows were allocated into a control group (n = 167 cows) and ASP group (180). Control cows were not subjected to pregnancy diagnosis via palpation per rectum. Per rectal ASP was performed between days 34 and 43 by only 1 experienced veterinarian. All cows were reevaluated with TRUS on days 45, 60, and 90. RESULTS: 21 cows were removed because of illness. Pregnancy loss between days 29 and 90 occurred in 44 of 347 (12.7%) cows. Pregnancy loss for the control and ASP groups from days 29 to 90 occurred in 22 of 167 (13.2%) and 22 of 180 (12.2%) cows, respectively. Late embryonic pregnancy loss (days 29 to 45) for the control and ASP groups occurred in 18 (10.8%) and 15 (8.3%) cows, respectively. Early fetal pregnancy loss (days 46 to 60) for the control and ASP groups occurred in 2 of 149 (1.3%) and 6 of 165 (3.6%) cows, respectively, and late fetal pregnancy loss (days 61 to 90) for the same groups occurred in 2 of 147 (1.4%) and 1 of 159 (0.6%) cows, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Pregnancy diagnosis via per rectal ASP during early gestation did not increase pregnancy loss in dairy cattle.