Abstract
The requirements for the successful artificial insemination with mice and rats were investigated in following points; an induction of pseudopregnancy, determination of the optimum time of insemination, extraction of semen, diluent for semen, and the technique of semen injection.
Physiological salt solution, Rock solution and glucose-phosphate-buffer solution were compared as a diluent of sperms. The Rock solution was found to be the best among above three sorts of diluent in regard to the survival and vitability of sperms.
The artificial insemination was performed with 16 mice employing thus established techniques. Four out of 10 mice artificially inseminated at night 9 to 12 p. m. underwent normal delivery, while in contrast to this, not even a single trial ensued successful with 6 females inseminated during daytime through night earlier than 8 p.m. So far in a single rat, inseminated at 9 p.m., pregnancy and delivery proceeded normally.
In the artificial insemination either in mice or in rats at night, the rate of the successful performance was apparently higher when females were injected with the sperm suspension at the same time as natural mating.
