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