view - Department of Reproduction, Obstetrics and Herd Health
view - Department of Reproduction, Obstetrics and Herd Health
view - Department of Reproduction, Obstetrics and Herd Health
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PREFACE<br />
The first recorded case <strong>of</strong> artificial insemination (AI) in horses goes back to the Arabs in 1322,<br />
when a chief decided to steal semen from a rival’s stallion to use for one <strong>of</strong> his own mares (Bowen,<br />
1969). Still, it wasn’t until 1677 that spermatozoa were actually visualized by van Leeuwenhoek <strong>and</strong><br />
Ham using one <strong>of</strong> van Leeuwenhoek’s first microscopes. These so called “animalcules” were<br />
described as living creatures with a tail <strong>and</strong> have been studied ever since. In 1781, Spallanzani<br />
described the influence <strong>of</strong> temperature on the motility <strong>of</strong> these animalcules. He found that cooling in<br />
ice reduced their motility, <strong>and</strong> after subsequent warming the animalcules became motile again<br />
(Gonzalès, 2006).<br />
Between the first reported AI from the Arabs <strong>and</strong> the research during the late 19 th century by<br />
Sir Walter Heape, equine AI languished in silence. Early research in reproductive work was done by<br />
Heape, a student from the University <strong>of</strong> Cambridge <strong>and</strong> a pioneer in embryo transfer in the rabbit<br />
(Heape, 1890). He also collected semen from a stallion followed by successful inseminations in mares<br />
(Heape, 1898). Continuing research in horse reproduction <strong>and</strong> in utero development was performed<br />
by Sir John Hammond, who carried out reciprocal inseminations <strong>of</strong> Shire mares with Shetl<strong>and</strong> stallion<br />
semen <strong>and</strong> vice versa to examine the maternal effect on growth <strong>and</strong> conformation (Walton <strong>and</strong><br />
Hammond, 1938). Unfortunately, most <strong>of</strong> the early work which was done by the Russians <strong>and</strong> the<br />
Chinese between 1930 <strong>and</strong> 1960 remained unpublished, hidden by the Iron Curtain <strong>and</strong> language<br />
barriers (Allen, 2005). In the late 1960s, equine AI revived with the work <strong>of</strong> B.W. Pickett <strong>and</strong> his large<br />
group <strong>of</strong> co-workers who worked on the collection, dilution, cooling, freezing, <strong>and</strong> insemination <strong>of</strong><br />
stallion semen. Much <strong>of</strong> this work is summarized by Squires et al. (1999).<br />
The acceptance <strong>of</strong> AI by the majority <strong>of</strong> horse breed registries <strong>and</strong> the possibility to transport<br />
cooled <strong>and</strong> frozen semen, have changed the entire horse industry <strong>and</strong> equine reproduction in<br />
particular. This widespread use <strong>of</strong> “processed” semen does not only increase the breeder’s<br />
possibilities but also surfaces challenges for the researchers <strong>and</strong> veterinarians harvesting <strong>and</strong><br />
preparing these AI doses. First <strong>of</strong> all, there is the never ending quest to increase the pregnancy rates<br />
(requiring improved processed semen), <strong>and</strong> secondly, following human <strong>and</strong>rology, st<strong>and</strong>ards need to<br />
be formulated when examining that semen, so the quality can be assessed worldwide using the same<br />
criteria.<br />
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