Embryonic development in rabbits after insemination with spermatozoa stored at 37, 5 or -196 C for various periods

Abstract

Rabbit spermatozoa stored at 37 degrees C for 5 hr, 5 degrees C for 5 hr or 5 days, and-196 degrees C for 5 hr, 5 days, or 1 year were used to artificially inseminate does induced to ovulate normal or excess numbers of eggs. Fertility and subsequent embryonic development were examined. Frozen spermatozoa stored for 5 hr fertilized fewer oocytes than those stored for 5 days or longer. Fewer embryos were recovered on Day 6 than on Day 2. Blastocysts were smaller when spermatozoa were stored for 5 days, were frozen or were placed in superovulating does, but no statistically significant differences in the % of fetal survival were found in the groups of normally ovulating does. Embryonic wastage associated with storage of spermatozoa resulted from a reduced fertilization rate and/or increased embryonic mortality before implantation.

Effect of cooling and freezing, the two first steps of a freezing protocol, on the fertilizing ability of the rabbit sperm

“…IV), which was in agreement with the results reported by Maurer et al [9], who observed a 45% cleavage rate (from total recovery) when inseminating with frozen sperm. The low number of total embryos recovered could indicate a problem in the transport of sperm (very few sperm are able to reach the oviducts to fertilise oocytes, although Murdoch and O'Shea, [12], observed fewer sperm in the oviducts of females inseminated with frozen sperm, but the differences between fresh and frozen sperm were not significant) since other authors have reported fewer accessory sperm in oocytes from females inseminated with frozen sperm [9,12,14]. This could also indicate a very low viability of the spermatozoa (they could reach the oviducts, but they would remain alive for a very short time) or any other problems which could 195 …”

“…The results obtained were in agreement with those obtained by Stranzinger et al [18] working with sperm which had been diluted with a tris-egg yolk-DMSO extender (final concentration of DMSO: 12.5%), and which had been stored for 6 or 8 h at 5 ºC before being used for insemination; the percentage of does kidding was 67%, with 6.5 rabbits/female kidding, but no females were inseminated with fresh sperm for comparison. Maurer et al [9], used the same extender as Stranzinger et al [18], and they compared the results for sperm which had been stored for 5 h at 37 ºC or 5 ºC; they induced ovulations 5 h before they inseminated, and they did not observe any difference in the percentage of cleaved embryos (recovered 32 h after insemination) between sperm which had been stored at 37 ºC (81%) or 5 ºC (87%), nor in the percentage of blastocysts recovered (68% for sperm at 37 ºC and 62% for sperm at 5 ºC), but there seemed to be a delay in the development of embryos produced by sperm stored at 5 ºC, since only 59% of the blastocysts recovered were classified as normal (81% for sperm at 37 ºC), but 68% of the foetuses were recovered at term (and 64% for sperm at 37 ºC). It could be concluded from the work of Maurer et al [9] that rabbit sperm does not lose its fertilising ability even when stored with DMSO at 37 ºC, so it is logical that we did not find any bad effects produced by DMSO after loading the straws at room temperature.…”

A sucrose-DMSO extender for freezing rabbit semen

“…This is because of the generally unsatisfactory results with frozen semen (Stranzinger et al, 1971;Maurer et al, 1976; Hanada and Nagase, 1980; Constantini, 1989;Fargeas, 1995). In order to better utilize semen from males of high genetic value, for production as well as for conservation and genetic programmes, use of frozen semen is important.…”

Cryoprotective effects of some amides on rabbit spermatozoa

“…Early attempts to achieve fertilization with rabbit semen frozen and thawed in the presence of glycerol were relatively unsuccessful, but better results were achieved using ethylene glycol (Fox & Burdick, 1963) or dimethylsulphoxide (Sawada & Chang, 1964) as cryoprotective agents. High kindling rates with frozen rabbit semen have been documented and observations have been made on several factors relating to rabbit semen freezing, such as sperm numbers for inseminations (Andrieu & Courot, 1976), acrosome morphology (Weitze, Hellemann & Krause, 1976;Hellemann, 1977), storage periods (O'Shea & Wales, 1969;Maurer, Stranzinger & Paufler, 1976), sperm transport in the female reproductive tract (Murdoch & O'Shea, 1973) and freezing procedures (Stranzinger, Maurer & Paufler, 1971;Weitz et al, 1976). However, no cryoprotective agents other than glycerol, dimethylsulphoxide and ethylene glycol have been examined for the low temperature preservation of rabbit semen.…”