Category Archives: frozen semen

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 »

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 »

Protocol for frozen semen insemination in mares

Posted: | May 12, 2026

Timing Protocol Modification for Frozen Semen Insemination in Mares There are in use a variety of protocols for frozen semen insemination. This research compares the results from several currently used with those from a new timing protocol. Background: There is a growing demand for use of frozen semen in equine artificial insemination practices Classic protocols rely on time-intensive… 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 »

ISER XIII

Posted: | August 6, 2023

ISER XIII “Snippets” – Held in Brazil in August 2023, ISER XIII produced a variety of useful research with immediate clinical value, here we review some of the presentations The thirteenth International Symposium on Equine Reproduction (ISER XIII) was held in Foz do Iguaçu, Brazil between July 10th–14th, 2023. Around 400 veterinarians, researchers and animal scientists were present,… Read More »

Frozen Equine Semen – An Overview

Posted: | October 30, 2021

Frozen Equine Semen – An Overview – Some horse breeders are unsure about the use of frozen equine semen. In this overview, we offer some of the pros and cons. Written and presented at the ApHC 2001 World Show, Fort Worth, Texas by Jos Mottershead (with later updates in red) Frozen equine semen advantages include: There are no… Read More »

Individual Tuition

Posted: | December 17, 2020

One-on-one Horse Breeding Training While we are renowned for offering short courses on the subject of horse breeding worldwide, we not infrequently encounter people either at the courses or through our website who are in need of more specific one-on-one horse breeding training. Perhaps they do not own stallions but want to learn more about the reproductive aspects… Read More »