Equine fetal sex determination using a single ultrasonic examination under farm conditions.

The study explores the reliability of using a single transrectal sonogram to determine fetal sex in pregnant mares under farm conditions and the feasibility of extending the gestation period for the examination.

Summary of Research

• The research was conducted during routine reproductive examinations on three different stud farms, with the aim of evaluating the feasibility and reliability of a single transrectal sonogram for fetal sex determination in pregnant mares.
• The study involved forty mares between the 54th and the 89th day of their gestation. Each mare was examined once, with the gestation period calculated from the last day of mating as Day 0.
• The researchers sought to determine the accuracy of their method by comparing their sex determinations with the actual sex of the foals at birth. There were two mares in the study for which this information was unavailable.

Findings of the Research

• Of the forty mares studied, the researchers were able to make a sex determination in 35 (87%) of them. The remaining 5 (12%) mares were not determinable due to insufficient data.
• The accuracy of their sex determinations was 65%, with a correct diagnosis made in 26 out of 40 cases. However, 9 out of 40 (22%) of the sex determinations were incorrect.
• A comparison of the percentages, done using a chi2-test, yielded a P value of 0.0011. P value is a statistical measure that helps scientists determine the significance of their results. The lower the p-value, the greater the statistical significance of the observed differences.
• Despite the positive statistical analysis indicated by the low P value, the relatively high percentage of incorrect diagnoses (22%) led the researchers to conclude that these results are not sufficient to justify systematic use of this approach for fetal sex determination in pregnant mares.