In case of bulls, sperm motility is a fairly reliable indication of the viability of fresh
and frozen semen (Grahman et al. 1980). Sperm motility has an important role in fertility
because during copulation, cervical mucus represents a barrier which allows only migration
of progressively motile spermatozoa with normal morphology and high nuclear stability
(Rodriquez-Martinez et al. 1997).
The average percentage of spermatozoa motility, live spermatozoa, and abnormal
spermatozoa of both Simmental and Limousin are presented in Table 2. Simmental bulls
have the mean percentage of sperm motility 39.00±5.48% while Limousin ones have
36.00±2.24%. On average, Simmental bulls have the higher mean proportion of sperm
motility than that of Limousin. Donors have the same age (5 years old), therefore this is
presumably influence of age of spermatozoa, sperm maturity, seminal plasma and sperm
membran integrity (Ax et al. 2000). Pratiwi et al (2009) reported that post thawing motility
of Limousin of 2-3 years old in Blora, Central Java, Indonesia, is 41.5%. These Limousin
frozen semen were thawed for 45 seconds in a 25-30ºC water bath.