Comparison of a Barium Chloride Test with ELISA for Pregnancy Detection in Cows

Abstract

Introduction: Early detection of pregnancy is vital for appropriate reproductive management programmes to facilitate the rapid re-insemination of non-pregnant females and reduce the calving interval.

Material and methods: A barium chloride test was compared with a commercial progesterone ELISA to detect pregnancy in non-descriptive cows and investigate if it could be applied as an alternative to ELISA in the field. Blood and urine samples were collected from 74 cows with recorded insemination dates. The progesterone ELISA and barium chloride assay were implemented to detect progesterone (P4) in blood and urine specimens, respectively. The cows' reproductive systems were examined after they were slaughtered to determine the uterus's status. Macroscopic examination of the uterus was used as a reference standard for both tests.

Results: The sensitivity rates of the P4 ELISA and barium chloride test to detect pregnant cows were 100.0% and 79.4%, and to detect the corpus luteum (CL) were 83.0% and 87.0%, respectively, their sensitivity increasing in the presence of the CL. The ELISA and barium chloride tests were 79.7% and 52.7% accurate in the diagnosis of pregnancy. The accuracy of the barium chloride test in CL detection increased to 81.0%, and that of the ELISA to 86.4%. There were no significant differences (P = 0.052) between the barium chloride assay and ELISA when they were utilised for the identification of the CL.

Conclusion: The barium chloride test can be an inexpensive and time-saving alternative to ELISA in pregnancy diagnosis when the insemination date is known.

Keywords: barium chloride; corpus luteum; cows; pregnancy diagnosis; progesterone.

Fig. 1

Scatter plots showing result quality by phase in the oestrous cycle. Plots (a) and (b) show the accuracy of the progesterone ELISA and barium tests for pregnancy detection, while (c) and (d) show the accuracy of the tests for CL detection