02409naa a2200229 a 450000100080000000500110000800800410001902400330006010000170009324500690011026000090017952018060018865000090199465000170200365000100202065000160203065300130204665300190205970000160207870000180209477300670211220757382017-09-18       1956    bl uuuu     u00u1 u    #d7 a10.2527/jas1956.152589x2DOI1 aHULET, C. V.  aFactors affecting sedimentation and motility of ram spermatozoa.  c1956  aThe effects of predilution temperature, age of sperm at dilution, length of time from dilution to sedimentation, temperature during sedimentation, and individuality of ram on rate of change in optical density (sedimentation rate) of spermatozoa, and the correlation of sedimentation rate and motility have been studied. The semen was diluted to a standard sperm concentration (optical density of 70) in a 0.1 molar sodium citrate solution by use of an electrophotometer using a green filter with a wave length of approximately 525 millimicrons. Following a given period of sedimentation another optical density reading was obtained, and the rate of change in optical density per hour was then calculated. Semen kept at 21° C. prior to dilution and sedimentation had a significantly more rapid sedimentation rate than when kept at approximately 5° C. (P&lt.01). Also, with increase in sperm age at dilution up to four hours, there was a significant increase in sedimentation rate (P&lt.01).  With increase in time from dilution to the start of sedimentation there was a significant decrease in sedimentation rate (P&lt.01). Temperatures above room temperature during sedimentation depressed sedimentation rate (P&lt.01). Sedimentation rate was most rapid during the first two hours of sedimentation, then dropped off sharply but continued at a slow rate for many hours. The differences in sedimentation rate between rams was significant (P&lt.01).  The sedimented semen fraction had a greater percentage of motile sperm than did the floating fraction. The total and between-ram correlations between rate of change in optical density and motility were high (r=0.923 and 0.949) and significant (P&lt.01). Sedimentation rate appeared to be positively associated with motility, irrespective of treatment.  aRams  aReproduction  aSheep  aSpermatozoa  aMovement  aSemen diluents1 aPOPE, A. L.1 aCASIDA, L. E.  tJournal of Animal Sciencegv. 15, n. 2, p. 589-600, May, 1956.