Equine foetal gender determination in mid- to late gestational mares: A practical inquiry.

The research study focuses on the accuracy and feasibility of equine foetal gender determination (FGD) during mid to late gestation periods using B-scale ultrasonography. It found that ultrasonographic FGD is an efficient and accurate method, however it requires expertise and the right equipment.

Methodology

The researchers used a sample of 121 mares from various breeds that were at different stages of gestation, ranging from 120 to 270 days. Each mare was examined only once using B-scale ultrasonography, specifically the Esaote MyLab™ClassC. No sedatives were used and no shaving was done prior to examination. The examination process was completed within 15 minutes for all mares.

• For each observed pregnancy, the researchers first considered the gonads for gender determination.
• The final judgement was not solely dependent on the gonads but was made considering all visible foetal reproductive organs.

Findings

The study revealed that in three cases when the pregnancy stage was beyond 257 days, FGD could not be undertaken successfully. However, all the other mares, in which FGD was conducted, delivered healthy foals later on.

• The research found that in 98% of the cases (116 out of 118), the diagnosis made using the ultrasonographic method was accurate.
• However, the remaining 2 cases were misdiagnoses because only one characteristic was visible during the procedure and was misinterpreted.

Limitations and Conclusion

The study identified that for advanced stages of pregnancy, beyond 210 days, it becomes increasingly hard to get clear visibility of the inguinal region due to the foal’s extremities.

In conclusion, the researchers found that equine FGD during mid- to late gestation periods is feasible and highly accurate when ultrasonographic methods, particularly the B-scale variant, are employed. However, for effective diagnosis and interpretation, it requires a good ultrasound device and considerable expertise and experience in the field.