Vie CONG. INTERN. REPROD. ANIM. INSEM. ARTIF., PARIS, 1968, VOL. I

Table 1. The effect of cold shock and deep-freezing
on ram spermatozoa DNA

e

Estimate Control Cold Shock frzzzz;g
DNA (mg/10° sperm) 2.80 2.83 2.53%
Proportion of native DNA 1.00 1.00 0.97
% AT 52 55 55
Deviation of base sequence o2 .01 .03

from randomness

e e e a——————————————————————————————

* P£0.05 significantly different from control.
Mean values are given for 3 replicates.

 

Table 2. The effect of incubation on the DNA of ram spermatozoa
frozen under optimal conditioms

et e

Incubation after thawing

Estimate BREOTE . i imimiicsm ik
Freezing 0 4 hours 24 hours
DNA (mg/10° sperm) 2.88 2.85 2.43 2.,28%
Proportion of native DNA 1.01 1.02 0.94% 0.92%%
Z AT 54 54 53 54
Deviation of base sequence <05 .05 .04 .03

from randomness

e e ———————————————————————————————————————————————————

* P<0.05; ** PL0.0l. Significantly different from O hr
incubation. Mean values are given for 6 replicates.

One is led to suspect that similar alterations in the nature or
DNA content of frozen ram spermatozoa in the female genital tract
may be a factor contributing to the early embryonic mortality
associated with the use of frozen semen for insemination (8).

(8) S. SALAMON & R. J. LIGHTFOOT, 1967. Nature, 216: 194.

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