Two decades of control Himalayan rabbit reproductive parameters and spontaneous abnormalities in Japan.

The Himalayan rabbit, Chbb:HM, has been bred in a closed colony at our institute from 1971 through 1991. Cumulative reproductive and teratological data of 514 litters from control does in embryotoxicological Segment II studies carried out over this period are herein reported. If compared with other strains of rabbit, the observed pregnancy rate of 92.2% was high, and spontaneous mortality or abortions were rare. However, the average numbers of corpora lutea, implantation sites and viable fetuses per doe were somewhat low. A total of 30 malformations and 130 variations occurred among 2883 viable fetuses.