The suitability of the open pulled-straw (OPS) method for vitrifying bovine embryos was tested for goat embryos. Of 14 does receiving OPS-vitrified embryos, all became pregnant and 13 (93%) kidded. The corresponding values for an established conventional freezing program were 58% pregnant and 50% (6/12) kidding. Overall embryo survival amounted to 64% (18/28) for OPS-vitrified and 42% (10/24) for conventionally frozen embryos. All differences were statistically significant. It is concluded that OPS vitrification is a suitable method for cryopreserving caprine d-7 blastocysts.

This study was carried out to improve the freezability of buck semen using two different types of cryoprotectants supplemented with melatonin as antioxidant in cold and hot temperature of breeding season. Ejaculates from four mature Egyptian baladi bucks were pooled after collection. Semen was extended with Tris-fructose-citric containing egg yolk using glycerol and dimethyl sulfoxide supplemented with two doses of melatonin (10-6 M and 10-3 M) in addition to control group. Types of motility as well as velocity, enzymatic activity and expression profile of selected genes were measured. The results revealed that the progressive motility percentage was significantly higher in samples supplemented with low dose of melatonin (10-6 M) compared to high dose (10-3 M) in glycerol (74.4 versus 64.4) and Dimethyl Sulfoxide (DMSO) based extender (35.5 versus 32.9) in cold temperature. The same trend was found in samples cryopreserved with glycerol (75.1 versus 53.5) and DMSO (32.1 versus 22) in hot temperature. The results also demonstrated that CASA parameters (VAP and VCL) were significantly increased in low compared to high melatonin dose in glycerol based extender during cold and hot temperature. The activity of total antioxidant capacity (TAC) was significantly higher in samples supplemented with low (0.49 mM/L) than high melatonin dose (0.16 mM/L) in DMSO extender. CPT2, ATP5F1A and SOD2 genes were up regulated in glycerol based extender groups in cold temperature compared to other groups of this study. On the other hand, NFE2L2 gene was upregulated in groups cryopreserved with DMSO in hot temperature compared with all other experimental groups. Therefore, it could be concluded that the glycerol based extender in cold season supplemented with low dose of melatonin improved semen quality, antioxidant defense capacity and transcriptional profile, which may maintain the post-thaw fertilizing ability of buck semen.

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The most common way of detecting pregnancy in rabbits is by manual palpation. Real-time ultrasonography may be an alternative to be used in rabbit production units in the future if it turns out to be practicable. There is a paucity of scientific knowledge on the suitability of real-time ultrasonography for pregnancy diagnosis in rabbits. In the present study pregnancy diagnosis by transabdominal ultrasonography was compared to manual abdominal palpation in 28 mated New Zealand rabbit does. Ultrasonography with the aid of a real-time scanner, equipped with five MHz linear-array transducer and manual palpation were executed by one individual daily, beginning at day five after mating. For ultrasound scanning, does were restrained in a dorsal recumbent position and, to establish firm skin contact, gel was applied to the clipped caudal abdomen. Manual abdominal palpation provided a reliable diagnosis by day 10.9 ± 0.3. By ultrasonography, uterine fluid was detected 6.2 ± 0.2 days after mating; fetal heartbeat by day 7.8 ± 0.1. In the 20 does that went to term (71%), the reliability of both ultrasonic pregnancy detection (based on the observation of heart beat) and manual palpation was 100%. No abortions or stillborn kits were recorded and the kits born were normal and viable. In conclusion, real-time ultrasonography, being accurate, rapid and safe, may be considered as a viable alternative for other means of early pregnancy diagnosis in rabbits.

This investigation addresses the possibility of providing mouse embryos or other foreign objects with a protective mucin coat by transferring them into the oviduct of a live rabbit doe. Mouse embryos at the 8 or 16-cell stage, rabbit oocytes and latex spheres resembling mouse embryos in size were transferred to the ligated oviducts of ovulation-induced rabbit does. The does were killed 24 h later to have their oviducts flushed. A large proportion of the latex spheres (89%) and of the ovulated oocytes of the recipient does (92%) was recovered. The recovery rates for transferred rabbit oocytes, either intact or with the zona pellucida removed, were 61% and 51%, respectively, whereas that for mouse embryos was extremely poor (20%). Rabbit oocytes with or without zona were enveloped in a thick mucin coat regardless whether they had been transferred or ovulated by the recipients. The same applied to empty rabbit zonae. Mouse embryos and latex spheres were also covered by a mucin coat, but it was four times thinner. While residing in the rabbit oviduct, the mouse embryos continued developing to a stage comparable to what would have been expected in situ. During the subsequent in vitro culture, mouse embryos continued developing to the expanded blastocyst stage. They did, yet, not hatch from the zona. It may be concluded that particles of various origins, when placed into the oviduct of ovulated rabbit does, will be provided with a mucin covering which is, however, considerably thinner than that surrounding oocytes or zonae pellucidae originating from rabbits.