Pregnancy evaluation with a point-of-care pregnancy test in dairy cattle

Abstract

Primiparous and multiparous dairy cattle were evaluated for pregnancy using both transrectal ultrasonography and a point-of-care pregnancy test (Alertys OnFarm Test), which measures pregnancy-associated glycoproteins through lateral diffusion, between Days 28-34 of pregnancy results were compared. A total of 637 animals were included in this study. Pregnancy was confirmed via manual palpation between Days 57-64. Data on parity, calving, and time of artificial insemination (AI) were also collected and evaluated. Overall the accuracy of the lateral diffusion test was 93.1% with 98.9% sensitivity, 88.7 % specificity, 86.8 % positive predictive value, and 99.1% negative predictive value. In heifers, the Alertys OnFarm Test had 100% sensitivity and 81.6% specificity. In contrast, the test had a sensitivity and specificity of 98.5 and 89.5%, respectively for multiparous cows. The pregnancy loss between early diagnosis and confirmation increased with parity. Heifers suffered losses as low as 2.6%, whereas animals in the third parity had significantly more losses (17.9%). Season also affected losses with spring pregnancy losses being considerably higher than autumn losses. The veterinary workload was also evaluated. Using the combined method of pregnancy testing, animals were first tested with the lateral diffusion test; then, the test-negative animals were scanned again, and the number of scanned animals was reduced. The results ranged between 3274% on farms. We concluded that veterinary workload could be reduced by using the point-of-care test. However, farm-level differences may have affected the results of the present study.

Keywords: Cattle; PAG; Pregnancy diagnosis; Ultrasound; Veterinary workflow.