The objective of this study was to verify, if Progesterone could be used for estrussynchronisation in rabbits before superovulation to have a positive influence on the embryo yield. Juvenile hybrid rabbits (n =132) were divided into two groups. 18 days before slaughter one group was treated with 25 mg of Progesterone every other day subcutaneously. The other group was not treated. For superovulation with FSH (2,22 mg pFSH i.m. every 12 h for 3 days) respectively eCG ( 100 IE i.m. once 72 h before ovulation induction) equal parts of rabbits treated or untreated with progesterone were used. About 20 h after artificial insemination und ovulation induction animals were slaughtered and tubes were flushed. Ovaries from all animals were assessed macroscopic. From 44 ovaries microscopic slides were made to count also earlier follicle stages.
The greatest account of new sites of ovulation were assessed for Prog-FSH treated animals (63,00 ± 31,29). Also flushed objectives (42,06 ± 18,75) and recovery rate (67 %) were best in the Prog-FSH group. The number of zygotes (29,15 ± 20,81) was highest in Prog-FSH group, too.
The results of superovulation were not improved in Prog-eCG groups.
There was no detectable influence on earlier follicle development in progesterone treated does. In conclusion Progesterone for estrussynchronisation in rabbits before starting superovulation has a positive effect on embryo yield. Further investigations have to be done with respect to dosage, application route and duration of treatment to optimise the effect of progesterone pretreatment.