Predicting the Outcome of Equine Artificial Inseminations Using Chilled Semen

This study aimed to determine whether an analysis of stallion ejaculate could accurately predict the likelihood of pregnancy resulting from artificial insemination in mares. This study involved 46 inseminations of 41 mares, using 7 standardbred stallions over a 5-week period at an Australian pacing stud. Semen quality was assessed immediately after collection and again after chilling at similar to 5 degrees C for 24 h. The assessment involved evaluating ejaculate volume, sperm concentration, and motility parameters using an iSperm (R) Equine portable device. After the initial evaluation, a subpopulation of cells was subjected to a migration assay through a 5 mu m polycarbonate filter within a SamsonT isolation chamber over a 15 min period. The cells were assessed for their concentration, motility parameters, and ability to reduce the membrane impermeant tetrazolium salt WST-1. The data, combined with the stallion and mare's ages, were used to predict the likelihood of pregnancy, as confirmed by rectal ultrasound sonography performed 14 days post ovulation. The criteria used to predict pregnancy were optimized for each individual stallion, resulting in an overall accuracy of 87.9% if analyzed pre-chilling and 95% if analyzed post-chilling. This study suggests that an analysis of stallion ejaculate can be used to predict the likelihood of pregnancy resulting from artificial insemination in mares with a high level of accuracy.

Automated summary

This study aimed to determine if stallion ejaculate analysis could predict pregnancy resulting from artificial insemination in mares. The study involved 46 inseminations of 41 mares using 7 stallions over 5 weeks. Semen quality was assessed before and after chilling, and various parameters were evaluated. The data, along with the ages of the stallions and mares, were used to predict pregnancy with high accuracy.