| Warming rates of dilutedsemen samples in plastic vialsand in glass | |
| ampules | (Fig. 8) |
EFFECTS OF FREEZING PROCEDURES ON METABOLIC ACTIVITY OF BULL SPERM
By finding how methods of handling affect the sperm cells, one can sometimes improve the procedures to avoid harmful effects. Some attempts have been made in this laboratory to determine the effects of the freezing procedures on the metabolic activity of bull spermatozoa. These investigations have been limited in scope, involving the measurement of oxygen-consumption and estimates of sperm motility during and after incubation at 37° C. in a Warburg apparatus.
Effect of glycerol additions on oxygen uptake of diluted semen at 37° C. The effect of adding glycerol to diluted semen on oxygen consumption of the sperm was tested in a Warburg apparatus, using semen diluted with an extender consisting of one part egg yolk and one part 2.9 percent sodium citrate dihydrate. The yolk-citrate extender was added to the semen at a rate which brought the sperm concentration in 0.5 milliliter to 200 million to 500 million. An exact count was used to calculate the oxygen uptake per 108 sperm per hour (ZO2).
| Effect of glycerol additions on oxygen consumption of sperm at 37° C. | (Fig. 9) |
Glycerol in various percentages in 2.9 percent sodium citrate dihydrate solution was placed in the sidearm of the Warburg flasks. The diluted semen was held in the main compartment. After a 60-minute preliminary run, in which the rate of oxygen uptake of the sperm in yolk-citrate diluent was determined, the contents of the sidearm were tipped into the main compartment. The resulting glycerol percentages after mixing the sidearm and main compartment contents were 0, 4, 8, and 12 percent. Ten samples of semen were subsampled and the oxygen uptake of each was determined at all four levels of glycerol.