Effect of early pregnancy diagnosis by per rectum amniotic sac palpation on pregnancy loss, calving rates, and abnormalities in newborn dairy calves

Abstract

The objectives of the present study were to evaluate the effect of per rectal amniotic sac palpation (ASP) for pregnancy diagnosis during the late embryonic period on pregnancy loss, calving rates, and abnormalities in newborn calves. A controlled, randomized, blocked, blind experiment containing 680 lactating pregnant dairy cows with a viable embryo diagnosed by transrectal ultrasonography was performed. Two dairy operation sites (farm A and farm B) were selected. At each farm, the cows were randomly divided into control (CON) and ASP groups. The CON group was not subjected to pregnancy diagnosis via per rectum palpation. The ASP examinations were performed by one experienced veterinarian between Days 34 and 45 after breeding. All cows were reevaluated by transrectal ultrasonography only between 2 and 4 weeks later. Two calving rates were calculated: calving rate 1 (cows that calved from the initial number of pregnant cows) and calving rate 2 (cows that calved from cows pregnant at reexamination). In farm A, the percentages of early pregnancy loss were 11.5% (19 of 165) and 13.2% (24 of 182) for the CON and the ASP groups, respectively (P = 0.64). In farm B, the percentage of early pregnancy loss was 11.2% (19 of 170) for the CON group and 8.8% (14 of 159; P = 0.48) for the ASP group. In farm A, the percentage of late pregnancy loss was 7.6% (11 of 145) for the CON group and 5.5% (8 of 155; P = 0.39) for the ASP group. In farm B, the percentage of late pregnancy loss was 3.7% (5 of 137) for the CON group and 6.3% (8 of 127; P = 0.32) for the ASP group. In farm A, early pregnancy loss was higher than late pregnancy loss (12.4% vs. 6.3%; P = 0.01), and in farm B, the same tendency was detected (10.0% vs. 4.9%, for early and late pregnancy loss, respectively; P = 0.02). In farm A, calving rate 1 was 81.2% (134 of 165) for the CON group and 80.8% (147 of 182; P = 0.92) for the ASP group. Calving rate 2 for the same groups was 92.4% (134 of 145) and 94.8% (147 of 155), respectively (P = 0.68). In farm B, calving rate 1 was 77.7% (132 of 170) for the CON group and 74.8% (119 of 159; P = 0.55) for the ASP group. Calving rates 2 for the same groups were 87.4% (132 of 151) and 82.1% (119 of 145), respectively (P = 0.20). Two female calves with atresia coli were diagnosed only in the CON group. It was concluded that ASP during the late embryonic period for pregnancy diagnosis did not increase the pregnancy loss, affect calving rates, or produce abnormalities in calves.

Comparison between allantochorion membrane and amniotic sac detection by per rectal palpation for pregnancy diagnosis on pregnancy loss, calving rates, and abnormalities in newborn calves

“…Meanwhile, in all the studies reported, there was not a CON group for comparison [27,30,62,66]. The present outcomes are in concordance with a recent investigation in which ASP was used only during the late embryonic period and compared with a concurrent CON group of pregnant females throughout the gestation with no differences in calving rates detected [47]. Therefore, the present experiment not only agreed with this last study but also extends knowledge that the use of FMS for pregnancy diagnosis affected neither the late PRL nor calving rates.…”

“…In the design phase of this investigation, a power of 90% was chosen to decrease the probability of discovering "no difference" when real differences could exist (reduce potential false negative results); the main goal was to support the null hypothesis ¼ no difference among treatments when the alternative hypothesis was tested. In multiple independent studies [4,13,21,47], the designs were constructed to detect differences in PRL between 5% and 10% between groups using an error ¼ 0.05 and a b error between 0.2 and 0.1 (power 80% or 90%, respectively), and no divergences between PRP and control groups were detected. The proportion of PRL and calving rates for cows subjected to ASP, FMS, or TRUS was compared with the proportion for CON during the two periods by use of chisquared analysis or Fisher's exact test as appropriate [57,59].…”

“…Nonetheless, the root of atresia coli/ jejuni remains polemic and not completely understood [36,43,46]. In a recent controlled randomized blind experiment performed in two dairy operations with 680 pregnant cows to evaluate the effect of ASP during the embryonic period, no differences on PRL, calving rates, and abnormalities of newborns were detected [47]. Remarkably, two calves were born with atresia coli only in the CON group (which only received TRUS throughout gestation).…”

Establishment of fetal age equations based on ultrasound measurements in cross-bred Holstein cows

“…In our study, the strongest positive correlation coefficient (R 2 = 0.956) was showed in cubic regression. The equation of TrD selected is Y=14.583+29.878x-3.759x 2 -0.225x 3 . From day 60 to 70 of pregnancy, the trunk diameters of bovine fetuses were 20-30 mm.…”

“…Rectal palpation has been used for pregnancy diagnosis in cattle for many years [1]. However, this method is reliable earliest after 45 d post-breeding and criticized to be invasive [2,3]. Nowadays, ultrasound has been widely used for cattle reproduction and provided the practitioners a way to gather more information than via rectal palpation [4][5][6][7].…”