Category Archives: stallion

Effect of Semen Extenders on Pre-Freeze Shipped Semen

Posted: | July 19, 2026

Protective Effect of Semen Extenders on Pre-Freeze Shipped Semen During Refrigeration at 5°C for 24 Hours Refrigerating stallion semen at 5°C for 24 hour shipment prior to freezing offers a practical field-based alternative when on-site cryopreservation is not feasible. This study evaluated the effect of semen extenders on pre-freeze shipped semen in four commercial diluents used within a… Read More »

Stallion Dismount Latency and Pregnancy Rates

Posted: | July 11, 2026

Stallion Dismount Latency and Pregnancy Outcomes in Thoroughbred Horses In Thoroughbred natural service breeding, dismount semen — residual urethral semen collected after copulation — is routinely used as a proxy for ejaculate quality. This study investigated whether the duration a stallion remains mounted post-ejaculation (stallion dismount latency) influences both dismount sample composition and pregnancy outcomes. Study Design: 62… Read More »

Prolonged Storage of Post-thaw Semen

Posted: | July 4, 2026

Storage Conditions Affecting Prolonged Storage of Post-thaw Semen Field-based use of cryopreserved stallion semen is often limited by the equipment and expertise required for on-site thawing. Thawing centrally, then achieving prolonged storage of post-thaw semen and shipping it in a cooled state could simplify artificial insemination programs at locations remote from the laboratory or center, but optimal post-thaw… Read More »

Cryopreservation Extenders Content

Posted: | June 27, 2026

Egg Yolk Concentration, Cryoprotectant Type, and Cooling Rate Effects on Post-Thaw Stallion Sperm Quality Cryopreservation extenders vary widely in egg yolk content and the type of penetrating cryoprotectant used, with prior evidence suggesting amide-based cryoprotectants may reduce oxidative stress compared to glycerol alone. This study examined how egg yolk concentration, cryoprotectant combination, and pre-freeze cooling rate interact to… Read More »

Donkey Semen Cryopreservation

Posted: | June 20, 2026

Donkey Semen Cryopreservation with Different Permeable Cryoprotectants Optimizing cryoprotectant selection for donkey semen cryopreservation is critical, as excessive concentrations can negatively impact recipient mare fertility. This two-experiment study evaluated cryoprotectant type and concentration to identify the most effective preservation strategy for Pêga donkey semen. Experiment 1 — Cryoprotectant Type (5 donkeys, 20 ejaculates): Five cryoprotectants compared at 5%… Read More »

Epididymal Sperm Collection and Processing

Posted: | June 13, 2026

Epididymal Sperm Collection and Processing Epididymal sperm collection and processing represent the last opportunity for genetic material rescue following sudden stallion death or emergency castration. This study evaluated multiple collection and processing variables across 142 samples to develop a standardized, practitioner-ready protocol. Study Design: 142 samples collected from stallions undergoing elective orchiectomy (castration) Computer-assisted sperm analysis used for… Read More »

Predicting Breeding Soundness in Pre-, Peri- and Postpubertal Colts

Posted: | May 30, 2026

Predicting Breeding Soundness in Pre-, Peri- and Postpubertal Colts Background: The study aimed to identify parameters for predicting breeding soundness in colts at the youngest possible age Rearing colts for breeding is costly; early prediction of future fertility has significant economic value Study Design: 46 Warmblood colts examined at approximately 6 months, 20 months, and 30 months of… Read More »

Pharmacologically Induced Ejaculation in Stallions

Posted: | May 21, 2026

Pharmacologically Induced Ejaculation in Stallions Since Drs. McDonnell and Love pioneered research into Pharmacologically Induced Ejaculation in Stallions in the 1990s1, “chemical collection” has been a tool in many advanced stallion manager’s and veterinarian’s collection tool box. The original research produced a tried-and-tested protocol involving Imipramine and Xylazine, and ultimately was considered successful in about 70% of stallions,… Read More »

Seminal Plasma Impact on Foal Growth

Posted: | April 18, 2026

Is there a Seminal Plasma Impact on Foal Growth? This study investigated the downstream developmental consequences of seminal plasma (SP) exposure — or its absence — at the time of breeding, examining both placental gene expression and seminal plasma impact on foal growth trajectories over the first two years of life. Background & Purpose: SP proteins serve key… Read More »

Comparing DNA Damage Assays

Posted: | April 18, 2026

Comparing DNA Damage Assays in Equine Sperm Preservation Background & Purpose Preserving sperm DNA integrity is critical for successful equine assisted reproduction. While low-temperature storage is traditional, above-15°C methods have emerged to reduce cold shock damage. Oxidative stress during any preservation method can cause DNA damage. This study compared the sensitivity of two DNA damage assays — the… Read More »