Use of an immediate, qualitative progesterone assay for determination of day of ovulation in an equine embryo transfer program.

This study evaluates an immediate, qualitative enzyme-linked immunosorbent assay (ELISA) for determining the day of ovulation in an equine embryo transfer program, comparing its accuracy against quantitative ELISA and the traditional method of teasing.

Objective of Research

• The main aim of the study was to evaluate the accuracy of an immediate, qualitative ELISA that tests progesterone levels as a method for determining the day of ovulation in an equine embryo transfer program. This method was compared to quantitative ELISA testing and ‘teasing’, a traditional method of observing behavioral changes in the mare.

Research Methodology

• For the study, 27 mares’ plasma samples were collected from the third day of estrus, which is the period of sexual receptivity, to the second day of diestrus, which is the period after ovulation when the mare is not sexually receptive.
• Ovulation was detected through ultrasound examination. The researchers tested plasma progesterone concentrations using the qualitative assay and measured the time it took for progesterone levels to rise after ovulation.
• The scores from the qualitative assay were then compared to the progesterone concentrations in the same samples as obtained through the quantitative ELISA test.

Results and Conclusion

• The correlation between the scores from the qualitative and quantitative assays, represented through a contingency coefficient, was found to be 0.56.
• The accuracy in identifying the day of ovulation within a day using the three methods were as follows: qualitative method at 72% (36 out of 50 cycles), quantitative method at 88% (44 out of 50 cycles) and teasing method at 86% (43 out of 50 cycles).
• The results show a significant difference in accuracy between the qualitative and quantitative progesterone assays. The qualitative assay was less accurate compared to the other two, suggesting that it may be a less dependable method in an equine embryo transfer program when it comes to determining the day of ovulation.