SOME REPRODUCTIVE AND PRODUCTIVE STUDIES IN RABBITS

Abstract

Th.is work was carried out in IVF laboratory (International Livestock Management

and Training Center, ILMTC) Sakha, Kafr El-Sheikh Governorate, belonging to Animal

Production Research Institute. Agricultural Research Center, Ministry of Agriculture.

This study aimed to investigate the maturation, fertilization and development of rabbit oocytes in vitro as affected by season of the year, type of culture medium, source of oocytes and level of osmolarity. The present work comparised two main experiments. The first one dealt with in vitro maturation (IVM) with checking fetal calf serum (FCS) and bovine serum albumin (BSA) supplements, in vitro fertilization (IVF) and early embryonic development in vitro as affected by above mentioned factors. While the second one was designed to study IVF and early embryonic development for superovulated does slaughtered at two different periods. Experiment I:

J. A. Some morphological measurements on the ovary:

In this study I4 virgin female New Zealand white rabbits aged 6-7 months old were used without any treatment (untreated does). Another 14 females were injected with Pregnant Mare Serum Gonadotrophin (PMSG) hormone (75 IU) and slaughtered after 60 hrs of treatment (PMSG-treated does). Ovaries were excised from both groups to determine the effect of season of the year on left and right ovaries weights. number of corpora lutea (CL), number of follicles and number of oocvtes obtained/doe. Results obtained for this • experiment could be summarized as follows: I. Season of the year had a significant effect (P<0.001) on the left and right ovaries weights

for the untreated group. But this effect was not significant for the PMSG-treated group.

2. Season of the year significantly (P<0.05) affected the number of CL on the left ovary, while this effect was not significant for CL presented on the right ovary in the untreated group. In PMSG-treated group, season had no significant effect on the number of CL presented on the both ovaries. 3. Season of the year had a significant effeet (P<0.01) on the number of visible follicles presented on the left ovary of the untreated group, while this effect was not significant on the number of the follicles presented on the right ovaries in both groups and those presented on the left ovary of the PMSG-treated group. 4. Season of the year did not significantly affected the number of oocytes obtained from the

ovaries of the untreated group, while this effect was significant (P<0.05) for the PMSG•

treated group.