Analysis of Awassi Sperm Motility in Two Media at Different Levels of Temperature, pH and Osmolality

The effects of five levels of osmolality and pH as well as three temperatures on Awassi ram sperm motility parameters assessed by computer-aided sperm analyzer (CASA) in tyrode albumin lactate pyruvate (TALP) and egg-yolk-tris (YET) media were studied. Semen obtained from five adult Awassi rams were pooled and diluted in the above two media at 100, 200, 300, 400 and 500 mOsm/kg at temperatures of 4°, 20° and 37° degree celsius and also at pH levels of 5, 6, 7, 8 and 9 at the same temperatures. The osmolality, pH and temperature had a significant effect (P<0.05) on the percent motility (MOT %) and the percent of sperm showing progressive motility (PMOT %). With the exception of lateral head displacement, all the other CASA motility parameters were also significantly affected (P<0.05). Semen incubated in YET was able to tolerate osmolarities within 200 to 400 mOsm/kg range for MOT %. Alkaline condition at pH 9 had higher negative effect than acidic condition at pH 5. Compared to the 20 °C and 37 °C, the 4 °C had negatively affected MOT % and PMOT % and this was more obvious in TALP medium. In conclusion, our results suggest: 1) the significant effects of osmolality, pH and temperature on Awassi sperm incubated in both TALP and YET media and 2) the need for careful selection of temperature by which the semen may be manipulated during artificial insemination and in vitro fertilization experiments in these two media.