Chemical and Physical Properties of Semen 47 



concentration of motile spermatozoa has been amply confirmed by 

 studies on both bull and human semen (Anderson, 1946b; Eichen- 

 berger and Goossens, 1950; Bishop et al., 1954) but the existence of 

 a similar correlation between the rate of fructolysis and fertility 



100 - 



Control with buffered semen 

 inactivated by heating 



30 60 90 120 150 180 



Minutes of incubation at 37° C 



210 240 



Fig. 8. Fructolysis in bull semen (920,000 sperm/fil.) incubated at 37°; 

 the disappearance of fructose was measured in (i) bull semen which 

 has been diluted with half a volume 0-25m phosphate buffer pH 7-4, 

 (ii) unbuffered semen, and (iii) buffered semen inactivated by heating. 



(Mann, 1948a) 



is still a matter of dispute; it has been claimed for bull semen by 

 some authors (Gassner, Hill and Sulzberger, 1952) but was denied 

 by others (Bishop et al., 1954). In both cases, however, the material 

 used for the survey consisted mainly of bulls kept for breeding 

 purposes at Artificial Insemination Centres. More insight into the 

 relationship between fructolysis and fertility could probably be 

 gained by studies on semen from bulls of subnormal fertility. 



