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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1.3.1. St<strong>and</strong>ards for equine AI doses<br />
CHAPTER 1.3<br />
In literature, actual guidelines concerning the minimal requirements for an AI dose <strong>of</strong> equine<br />
semen are missing. The semen used for AI can be divided, based on preparation, into fresh/diluted<br />
semen, cooled (transported) semen <strong>and</strong> frozen-thawed semen. The World Breeding Federation for<br />
Sport Horses (WBFSH) has clear minimal requirements for each type <strong>of</strong> semen used for AI, based on a<br />
minimal percentage <strong>of</strong> progressive motility (PM) combined with a minimal dose <strong>of</strong> progressive motile<br />
spermatozoa (PMS) (Table 4).<br />
Table 4. Minimal requirements for a dose <strong>of</strong> equine semen following the WBFSH guidelines (source:<br />
http://www.wbfsh.com/files/Semen%20st<strong>and</strong>ards.pdf, website last visited November 23 rd 2010).<br />
Semen type<br />
Fresh semen ≥ 300<br />
Progressive Motile<br />
Spermatozoa (× 10 6 )<br />
Time between<br />
collection <strong>and</strong> AI<br />
Cooled semen ≥ 300 at portioning < 12h 35<br />
Cooled transported<br />
semen<br />
≥ 600 at portioning < 36 h 35<br />
Frozen semen ≥ 250 35<br />
Progressive Motility (%)<br />
In former days, 500 × 10 6 PMS was commonly recommended as st<strong>and</strong>ard AI dose for fresh<br />
semen (Picket et al., 1975), whereas more recent studies advise on a st<strong>and</strong>ard AI dose using fresh<br />
semen <strong>of</strong> 300 × 10 6 PMS (Vidament et al., 1997; Gahne et al., 1998). Nevertheless, a large variety <strong>of</strong><br />
studies present good fertility results with lower doses. Doses <strong>of</strong> 100 (Rigby et al., 1999), 50 (Sieme et<br />
al., 2004), <strong>and</strong> 25 × 10 6 total spermatozoa (Woods et al., 2000), respectively, can give good fertility<br />
results. Based on these data some authors suggest to reevaluate the sperm dose recommendations<br />
(Sieme et al., 2004). The findings <strong>of</strong> Rigby et al. (1999) imply that fertility status <strong>of</strong> the stallion might<br />
be more important than merely the numbers <strong>of</strong> sperm or PMS inseminated. However, the only<br />
possibility to report on a stallion’s fertility status to date is based on findings from in vivo fertility<br />
observations. In order to bypass this problem the semen can be evaluated after collection <strong>and</strong><br />
following an in vitro storage, a predictive value can be obtained.<br />
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