Unilateral intrauterine horn insemination of fresh semen in cats

The sperm count required were investigated to obtain a conception rate of 80% by unilateral intrauterine insemination (UIUI) of fresh semen in cats. The conception rates obtained by insemination before and after ovulation were also examined. Thirty-six female cats aged 1-7 years were used in the experiments, and the number of experimental cases was 44. Seven male cats aged 2-12 years from which semen could be collected by the artificial vagina method were used. In artificial insemination, 100 iu x 2 or 250 iu of hCG was administered on days 2-4 of estrus, and sperm were introduced into the uterine horn with a greater number of ovulations (or mature follicles) 15, 20 and 30 hr after hCG administration by laparotomy. The inseminated sperm counts were 2 x 10(6) (Exp. 1). 4 x 10(6) (Exp. 2), and 8 x 10(6) (Exp. 3). As a result, ovulation was induced in 42 of 44 cases (induction rate: 95.5%) regardless of the dosage of hCG. Conception was obtained by UIUI in two of 16 animals (conception rate: 12.5%) in the Exp. 1, five of 16 animals (31.3%) in Exp. 2, and eight of 10 animals (80.0%) in Exp. 3. Regarding the relationship between the ovulation state at insemination and conception, the conception rate obtained by insemination before ovulation was clearly higher than that obtained by insemination after ovulation (p<0.05). Regarding the number of kits compared to the number of ovulations on the inseminated side, the percentages of cases in which the number of kits exceeded the number of ovulations on the inseminated side were similar in all groups inseminated with a different number of sperm. It is therefore necessary to investigate conception rates obtained by bilateral insemination to increase the fertility rate. Based on the above findings, it was shown that the sperm count required for fertilization by UIUI is 8 x 10(6).     

Relationship between the number of sperms and the rate of implantation in bitches inseminated into unilateral uterine horn

Studies were made on the number of sperms required for fertilization of ova ovulated from the bilateral ovaries in bitches. The experiment was carried out with 44 female beagles, which were divided into four groups of seven to eleven bitches each. The four groups were inseminated with 40 X 10(6) sperms/0.2 ml, 20 X 10(6) sperms/0.1 ml, 10 X 10(6) sperms/0.1 ml, and 3-5 X 10(6) sperms/0.1 ml, respectively. All the bitches were laparotomized at an optimum time for mating and inseminated at the tip of the horn of an unilateral uterus. In the four groups conception took place at a rate of 7/7, 8/8, 10/11, and 2/7, respectively. The number of puppies exceeded the number of ova ovulated on the inseminated side at a rate of 5/7, 6/8, 0/10, and 0/2 in the four groups, respectively. Therefore, it was clarified that when more than 20 X 10(6) sperms/0.1 ml were inseminated in the ipsilateral uterine horn, ova ovulated on the contralateral side were fertilized also. Then a unilateral ovary was ovariectomized in 11 bitches, which were inseminated with 10 X 10(6) sperms/0.1 ml in the ipsilateral uterine horn. As a result, only one bitch became conceptive and gave birth to only one puppy. From these results, it was considered that 10 X 10(6) sperms/0.1 ml may be most adequate for the ova on the side of insemination alone to be fertilized.     

Factors affecting transuterine migration of canine embryos

Dogs, cats, and pigs have a bicornuate uterus, and transuterine migration of embryos occurs in 40% or more of pregnant animals. However, the mechanism of the transuterine migration has not been elucidated in dogs. Thus, we investigated the occurrence of transuterine migration of embryos when embryos were retained in an unilateral uterine tube with more ovulated ova (Experiment 1), when one ovary was excised (Experiment 2), and when ova ovulated from the right and left ovaries were fertilized with sperm from male dogs with different blood types (Experiment 3). Transuterine migration of embryos was observed in 7/8 (87.5%), 10/10 (100%), and 11/17 (67.4%) fertilized animals in Experiments 1, 2, and 3, respectively. In Experiment 3, intrauterine embryo mixing reported in pigs did not occur. These findings suggest that transuterine migration of embryos occurs due to the number of embryos that enter the uterus but that differences in the number of ovulated ova between the right and left ovaries or the number of embryos retained in the uterine tube do not affect the migration.     

Induced ovulation in cats using porcine pituitary gland preparation during the non-breeding season

An attempt was made to induce ovulation in 19 cats during the non-breeding season by the administration of a porcine pituitary gland preparation. The dosage was 2 mg for the first day and then 1 mg for each day until estrus was induced. Studies were made to determine whether fertilization and pregnancy were possible by mating at the time of induced estrus. Estrus was induced in 89.5% (17/19) of the cats, 3-8 days after the first administration. The average number of ovulations induced by mating was 7.3 +/- 1.3 (mean +/- SE) for 16 cats (excluding one cat that failed to ovulate). The uterine horn was flushed 6-8 days after mating in 9 of the 16 ovulated cats to determine the fertilization rate. An average of 3.6 ova were recovered from 8 out of the 9 cats (including one cat from which no ovum was recovered) which gave an average recovery rate of 38.6%. Expanded blastocysts were recovered from 5 cats, while from the other 3 cats, only unfertilized ova were recovered. Pregnancy was confirmed in the other 7 cats 15-20 days after mating. In two of the 7 cats implantation was observed, but abortion occurred at 24 and 27 days of pregnancy. Plasma progesterone concentrations were lower in the estrus-induced and bred cats as compared to these in the controls, with progesterone values approaching base concentrations, approximately by day 20 in 2 cats and by day 30 in 3 cats. It was concluded that estrus could be induced in cats during the non-breeding season by administration of porcine pituitary gland preparation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sperm migration in pigs after deep intrauterine and intraperitoneal insemination

Deep intrauterine insemination in pigs allows sperm deposition only into one uterine horn, but bilateral fertilization of oocytes occurs. How the sperm reach the contralateral oviduct remains disputable. The aim of this experiment was to study possible transperitoneal and/or transuterine sperm migration ways. Follicle growth and ovulation were induced in 24 peripubertal gilts with eCG and hCG 72 h after eCG. Endoscopic intrauterine insemination (IUI) was performed 32 h after hCG with 20 ml of extended semen (60 × 10(6) spermatozoa) as follows: Group CONTROL (n=8) received IUI into the right horn, and the left horn served as non-treated control; Group LIGATURE (n=8) received IUI into the right horn, and the left horn was closed by endoscopic double ligature close to the bifurcation; Group INTRAPERITONEAL (IPI; n=8) received IUI into the right uterine horn, the left horn was closed by double ligature and semen was deposited intraperitoneally at the surface of the left ovary. Genital tracts were removed 65-66 h after hCG, the oviducts were flushed and ova (n=299) were analyzed for fertilization and cleavage. Furthermore, the accessory spermatozoa count/oocyte was graded as 0, without spermatozoa, 1, <5 spermatozoa, 2, 5-50 spermatozoa, 3, 50-100 spermatozoa and 4, >100 spermatozoa. The results indicate that low dose IUI into one horn provides a lower grade of accessory spermatozoa in the contra-lateral side (1.6 vs. 2.8). No spermatozoa were found in ova flushed from oviducts of the ligated uterine horn, even after intraperitoneal insemination (P<0.05), and no fertilization occurred, respectively. Our results clearly indicate that after low dose IUI into one uterine horn, spermatozoa reach the contralateral oviduct via transuterine migration.     

Surgical intrauterine insemination with cat semen cryopreserved with Orvus ES paste or sodium lauryl sulfate

The mean post-thaw sperm motilities of feline frozen semen prepared with 1% OEP or 3 g/ml SLS as a cryoprotective agent, in addition to 7% glycerin, were 35.0 ± 2.4 and 37.0 ± 2.5%, respectively, showing no significant difference. On unilateral intrauterine insemination (UIUI) using these semen samples at a sperm number of 40 × 10(6), the conception rate was 70.0% (7/10) in the OEP group and 30% (3/10) in the SLS group, showing that the rate was higher in the OEP group, but the difference was not significant. It was suggested that sperm in frozen semen showing the above qualities were transferred to the contralateral uterine horn on UIUI.     

Unilateral intrauterine horn insemination of frozen semen in cats

Frozen feline semen was prepared using two types of extenders, egg yolk Tris-fructose citric acid (EYT-FC) and egg yolk sodium citrate solution (EYC), and the semen qualities after thawing and the conception rates obtained by unilateral intrauterine horn insemination (UIUI) were investigated. Cats used in the experiment were six males and 11 females aged 2-12 years (the number of experimental cases was 17). For preparation of frozen semen, semen collected by the artificial vagina method was adjusted to I x 10(8) sperm/m/ and 7% glycerol, put in 250 microl straws, and then frozen using a cell freezer. The mean sperm motility after thawing was 30.0+/-9.7 (SE) % in the semen prepared with EYT-FC and 30.0+/-3.3% in the semen prepared with EYC. Four of seven animals were fertilized by UIUI using two straws in both extenders, and the conception rate was 57.1%. The mean ratios of number of kits to the number of ovulations in the inseminated side were 61.1+/-24.5% and 30.5+/-3.4% for EYT-FC and EYC, respectively, showing that the ratio tended to be higher in the semen prepared with EYT-FC. The above findings, comparing the two extenders for preparation of frozen feline semen, showed that EYT-FC is slightly superior to EYC. To increase conception and fertility rates, it may be important to increase the sperm count for insemination and to inseminate both uterine horns.     

Artificial insemination with frozen epididymal sperm in cats

Artificial insemination with frozen cauda epididymal sperm was performed in cats. Sperm were transmigrated from the epididymides in 10 male cats. The mean sperm motility and viability were 67% and 82.5%, respectively, and 11.6 x 10(7) sperm were recovered. The mean sperm motility after thawing was 24.0%. Eleven female cats received unilateral intrauterine insemination of 5 x 10(7) sperm, and the conception rate was 27.3% (3/11). This was the first case of conception obtained with frozen epididymal sperm in cats.     

Artificial intravaginal insemination using fresh semen in cats

To clarify the sperm count required for fertilization by artificial intravaginal insemination (AIVI), twenty-nine female cats were examined. Six male cats aged 2-12 years with normal semen quality, copulation capability, and fertility were used. In AIVI, animals received administration of 250 iu hCG once or 100 iu twice on days 2-4 of estrus to induce ovulation, and were inseminated 15, 20, or 30 hr after the initial hCG administration. The success of ovulation was judged by elevation of the peripheral progesterone level after hCG administration. AIVI was investigated at three sperm counts, 20 x 10(6) (Experiment 1), 40 x 10(6) (Experiment 2), and 80 x 10(6) (Experiment 3), with semen collected by the artificial vagina method. Semen was infused in the vagina under general anesthesia by advancing a 9 cm-long nylon probe with 1.5 mm diameter connected to a 1 ml syringe in the vagina for 3-4 cm. Ovulation was induced in 43 of 45 animals (95.6%). One of 16 animals was fertilized (conception rate: 6.6%) by AIVI in Experiment 1. In Experiments 2 and 3, conception was obtained in six of 18 animals (33.3%) and seven of nine animals (77.8%), respectively, and the mean numbers of kits were 4.0 +/- 0.4 and 3.3 +/- 0.5, respectively, and the mean numbers of kits were 4.0 +/- 0.4 (SE) and 3.3 +/- 0.5, respectively, showing no significant difference. There were no differences in the time of insemination after hCG administration and the conception rate among these groups. Our findings showed that the number of sperm required for fertilization by AIVI of fresh semen in cats was 80 x 10(6).     

Accessory sperm: their importance to fertility and embryo quality, and attempts to alter their numbers in artificially inseminated cattle.

Accessory sperm number and its relationship to fertilization and embryo quality was evaluated in cattle after nonsurgical recovery of ova or embryos 6 d after insemination. Efforts to alter accessory sperm number per ovum included 1) blockage of retrograde sperm loss at insemination using a modified insemination device, 2) elevated sperm number per inseminate (40 x 10(6) vs 20 x 10(6], and 3) alteration in semen quality (percentage of viable and morphologically normal sperm in the inseminate). None of these efforts affected accessory sperm number per ovum or embryo. However, blockage of retrograde semen flow for 3 h or use of semen of below-average quality (decreased percentage of viable and morphologically normal sperm) resulted in significant decreases in number of viable embryos and increases in number of degenerate embryos and unfertilized ova compared with conventional insemination (P less than .03) and use of semen with an average percentage of viable and morphologically normal sperm (P less than .06). Number of accessory sperm per embryo or ovum was positively related to fertilization and embryo quality (P less than .05). Mean accessory sperm +/- SD and the median value (in parentheses) for unfertilized ova, degenerate embryos, and embryos classified fair to poor and excellent to good were, respectively, .3 +/- .8 (0), 5.4 +/- 8.9 (1.0), 15.8 +/- 28.6 (3.5), and 16.9 +/- 29.5 (5.0). We conclude that efforts to improve accessory sperm numbers per embryo or ovum failed and that high variation and skewness of accessory sperm toward 0 may make median values more meaningful than means.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of unilateral cornual insemination upon fertilization rate in superovulating and single-ovulating cattle

In Exp. 1, 21 first-service cattle and seven repeat-breeder cattle, averaging 4.7 infertile services, were brought into estrus and superovulated by treatment with follicle-stimulating hormone and prostaglandin F2 alpha. At insemination, semen was deposited in the greater curvature of one uterine horn, about midway between the utero-cervical junction and the utero-tubal junction. Cattle were necropsied 2 to 7 d after estrus and ova were recovered and examined. The fertilization rate for first-service cows was 74% of 362 intact ova and for repeat-breeders, 43% of 128 intact ova (P less than .001). Fertilization rate in first-service cows was 81% on the side of semen deposition and 68% on the opposite side (P less than .01); the rates in repeat-breeders were 54% and 32% (P less than .025). Differences between sides were due mostly to four cows that averaged 93% fertilization on the side of semen deposition and 19% on the opposite side. The proportion of fertilized ova with accessory sperm (17%) did not differ between sides of the reproductive tract. In Exp. 2, 60 first-service and 32 repeat-breeder cows in natural estrus had semen deposited in the uterine body or in the greater curvature of one uterine horn, either on the side of impending ovulation or on the opposite side. At necropsy, 55 ova were recovered from first-service cows, of which 42 (76%) were intact and 13 (24%) were ruptured or fragmented. Of the 42 intact ova, 41 (98%) were cleaved. From the 32 repeat-breeders, 30 ova were recovered, of which 26 (87%) were intact and 4 (13%) were ruptured; 23 of the 26 intact ova (88%) were cleaved. Site of semen deposition had no significant effect on either fertilization rate or number of accessory sperm in either type of cow. First-service cows averaged more accessory sperm (40) than did repeat-breeders (19, P less than .01). Overall results indicated that sperm deposited deep in one uterine horn fertilized ova nearly as frequently in the opposite oviduct as in the adjacent oviduct except in 14% of superovulating cattle.     

Evidence for transuterine migration of embryos in the domestic cat

A total of 169 pregnant cats presented for ovariohysterectomy were examined for the number of corpora lutea (CL) and the number of fetuses per uterine horn. The implantation rate and the frequency of occurrence of transuterine migration of embryos were calculated. The average number of CL was 5.6 +/- 1.9 (mean +/- SD; range, 2-11), the average number of fetuses was 4.5 +/- 1.4 (range, 1-8) and the average implantation rate was 84 +/- 20%. Transuterine migration occurred in 69/169 cats (40.8%). In animals with a 100% implantation rate, transuterine migration occurred in 50/84 cats (59.5%). The number of embryos that migrated ranged from 1-3 per animal and embryos moved from the uterine horn ipsilateral to the ovary with the larger number of CL in 66/69 cats (95.7%). As a result of transuterine migration, the difference in the number of fetuses between uterine horns as compared with the difference in the number of CL between ovaries was smaller in 54 casts (78.3%), unchanged in 8 cats (11.6%) and larger in 7 cats (10.1%). These results indicate that cats tend to equalize the number of fetuses between uterine horns by transuterine migration of embryos.     

Comparison of fertility on intrauterine insemination between cryopreserved ejaculated and cauda epididymal sperm in dogs

The fertility was compared between ejaculated and cauda epididymal sperm sensitized with prostatic fluid in dog after freeze-thawing using the fertility of ova from the contralateral ovary after injection (2 × 10(8) sperm) into dog uterus on the unilateral ovariectomized side, on the basis of the presence or absence of conception. No significant difference was observed in sperm quality after freeze-thawing between the two groups and conception rates were equivalent and low. Therefore, to achieve a high fertility by intrauterine insemination of canine frozen-thawed ejaculated and cauda epididymal sperm, intrauterine insemination on both sides is recommended, rather than insemination with a lot of sperm of the uterine horn on one side.     

Distribution of Spermatozoa and Embryos in the Female Reproductive Tract after Unilateral Deep Intra Uterine Insemination in the Pig

The present study was performed to investigate the number of either the spermatozoa or the embryos in the reproductive tracts of sows after unilateral, deep, intra uterine insemination (DIUI). Two experiments were conducted, 10 sows were used in experiment I and eight sows were used in experiment II. Transrectal ultrasonography was used to examine the time when ovulation took place in relation to oestrus behaviour. The sows were inseminated with a single dose of diluted fresh semen 6-8 h prior to expected ovulation, during the second oestrus after weaning. In experimental I, five sows were inseminated by a conventional artificial insemination (AI) technique using 100 ml of diluted fresh semen, containing 3000 x 10(6) motile spermatozoa and five sows were inseminated by the DIUI technique with 5 ml of diluted fresh semen, containing 150 x 10(6) motile spermatozoa. The sows were anesthetized and ovario-hysterectomized approximately 24 h after insemination. The oviducts and the uterine horns on each side of the reproductive tracts were divided into seven segments, namely ampulla, cranial isthmus, caudal isthmus, utero-tubal junction (UTJ), cranial uterine horn, middle uterine horn and caudal uterine horn. Each segment of the reproductive tracts was flushed with Beltsville thawing solution (BTS) through the lumen. The total number of spermatozoa in the flushing from each segment were determined. In experimental II, eight sows were inseminated by the DIUI technique using 5.0 ml diluted fresh semen containing 150 x 10(6) motile spermatozoa. The sows were anesthetized 61.1 +/- 12 h after insemination (48-72 h) and the embryos were flushed from the oviduct through the proximal part of the uterine horn. It was revealed that, in experimental I, the spermatozoa were recovered from both sides of the reproductive tract in the AI-group, and from unilateral side of the reproductive tract in the DIUI-group (three sows from the left and two sows from the right sides). The number of spermatozoa recovered from the reproductive tracts was higher in the AI- than the DIUI-group (p < 0.001). In experiment II, fertilization occurred in five of eight sows (62.5%) after DIUI. The number of ova that ovulated were 16.4 +/- 2.6 per sow and the embryos numbering 11.4 +/- 2.3 per sow were recovered from both sides of the reproductive tract. In conclusion, the spermatozoa given by DIUI could be recovered from only one side of the reproductive tract of sows at approximately 24 h after DIUI via the flushing technique. However, embryos were found in both sides of the oviducts and the proximal part of the uterine horns 48-72 h after insemination, indicating that the fertilization occurred in both sides of the oviducts.     

The effect of porcine follicular fluid on the interaction of boar spermatozoa with zona-free hamster ova.

Boar spermatozoa were cocultured with zona-free hamster ova (eggs) to assess the effects of preovulatory porcine follicular fluid (pFF) in the capacitation medium or gamete coculture (fertilization) medium (pFF; 0, 10 or 40% v/v) on subsequent sperm-egg interaction. Increasing pFF concentrations in the capacitation medium resulted in a progressive decrease in the average numbers of sperm attaching to or penetrating each ovum. When pFF was included in the fertilization medium, but not in the capacitation medium, the average numbers of sperm attaching to or penetrating each ovum and the percentage of ova with sperm attached decreased markedly with increasing pFF concentrations. The percentage of ova with greater than five sperm attached decreased from 84% to 13% and 0% with 0%, 10% and 40% pFF, respectively. Sperm attachment was completely inhibited in approximately 50% of the ova cocultured in 40% pFF. The percentage of ova penetrated by greater than five sperm decreased from 82% to 21% and 7% with 0%, 10% and 40% pFF, respectively. Preincubation of ova in 40% pFF prior to coculture with sperm also resulted in a reduction in sperm attachment and penetration. These results suggest that pFF contains substance(s) that alter the ability of boar spermatozoa to interact with the hamster ovum plasma membrane in vitro.     

The effect of time of artificial insemination on fertilization status and embryo quality in superovulated cows

Thirty nonlactating Holstein cows were superovulated to determine the effect of artificial insemination time on fertilization status and embryo quality. During the luteal phase of the estrous cycle, cows were administered 38 mg FSH-P in a 4-d descending dose regimen. Luteolysis was induced with two injections of prostaglandin on the last day of FSH-P treatment. All cows were continuously monitored for behavioral estrus using the HeatWatch estrus detection system. All cows were inseminated once with one .5-mL straw (50 x 10(6) sperm) at either 0 (n = 10), 12 (n = 10), or 24 h (n = 10) after the first standing event. The elapsed time (mean +/- SD) from the first prostaglandin dose to the first standing event was 39.4 h +/- 7.7 h. The (mean +/- SD) duration of behavioral estrus was 13.2 h +/- 4.1 h. The (mean +/- SD) number of standing events was 27 +/- 17. Five hundred twenty-nine embryos and ova were recovered nonsurgically 6 d after insemination. Fertilization rates were 29 (0 h), 60 (12 h), and 81% (24 h) (P < .01). Percentages of excellent and good, fair and poor, and degenerate embryos were not different (P > .05). Percentages of embryos with accessory sperm were 5 (0 h), 8 (12 h), and 41 (24 h) and differed between the 0 and 24 h and the 12 and 24 h inseminations (P < .01). Artificial insemination of superovulated, nonlactating Holstein cattle 24 h after onset of estrus increased fertilization rate and percentage of embryos with accessory sperm compared with insemination at 0 or 12 h after onset of estrus. Embryo quality was not affected by time of insemination.     

Intrauterine and intravaginal insemination with frozen canine semen using an extender consisting of orvus ES paste-supplemented egg yolk tris-fructose citrate

Our previous report indicated that addition of Orvus ES Paste (OEP) to the extender of frozen canine semen protected acrosomes and maintained sperm motility after thawing. In this study, artificial insemination (AI) using the frozen semen was carried out. The frozen semen was prepared using egg yolk Tris-fructose citrate, and the final concentrations of glycerol and OEP were 7% (v/v) and 0.75% (v/v), respectively. AI was performed during the optimal mating period predicted from the peripheral plasma progesterone level. In intrauterine insemination (IUI), the bitches were laparotomized and 1 x 10(8) spermatozoa were infused into one of the uterine horns. In insemination of non-OEP supplemented semen, 3 x 10(8) spermatozoa were inseminated. In intravaginal insemination (IVI), 10-40 x 10(8) spermatozoa were inseminated. Conception was obtained in nine of 10 bitches (90.0%) that underwent IUI. The number of newborns was from 1 to 7 (mean 3.6 +/- 0.9). The mean ratio of the number of puppies to the number of ovulations in the inseminated uterine horn was 71.8%. The number of puppies did not exceed the number of ovulation in the inseminated uterine horn. Conception using non-OEP supplemented frozen semen was unsuccessful in all four bitches. In IVI, conception was not obtained in any of the six bitches that received insemination of 10 x 10(8) or 40 x 10(8) spermatozoa, but two of three bitches that received insemination of 20 x 10(8) spermatozoa were fertilized. It was shown that a high conception rate can be obtained by IUI using OEP-supplemented frozen canine semen. Developmenmt of a non-surgical method of IUI and a method of freezing canine sperm applicable to IVI is necessary.     

In vitro production of sexed embryos for gender preselection: high-speed sorting of X-chromosome-bearing sperm to produce pigs after embryo transfer

The objectives for the present experiments were to apply sperm sexing technology to an in vitro production system with porcine oocytes obtained from slaughterhouse material. On six experimental days, ovaries were obtained from an abattoir, and cumulus-oocyte-complexes were matured in vitro. Semen was collected from mature boars of proven fertility and was sorted for X-chromosome-bearing sperm, using the Beltsville Sperm Sexing Technology incorporating the use of high-speed sorting. A total of 5,378 oocytes were submitted for in vitro fertilization (IVF). Of these, 559 ova were stained for cytogenetic analysis 18 h after IVF. From the remaining 4,819 ova, 1,595 cleaved, and 1,300 of the cleaved embryos were transferred into 26 synchronized recipients (5 control gilts for unsorted sperm, 21 gilts for X-sorted sperm). In a test of two fertilization media (FERT-A vs FERT-B) higher cleavage rates (P<.05) were obtained when FERT-B was used as a fertilization medium for unsorted (43.4+/-5.1%) and sorted sperm (43.1+/-1.1%;), whereas in FERT-A unsorted sperm gave a cleavage rate of 17.9+/-4.4% and sorted sperm gave 30.4+/-1.4%. Additionally, cleavage rates were higher (P<.05) after fertilization with sorted sperm vs unsorted sperm, independent of fertilization medium. Cytogenetic analysis of ova revealed that more oocytes with unsorted than with sorted sperm remained in Metaphase 2 arrest (P<.05). This was also independent of the fertilization medium. Monospermic fertilization rates were the same for IVF with unsorted or sorted sperm, independent of the fertilization system, except FERT-A with unsorted sperm (P<.05). Polyspermic fertilization rates were highest in FERT-B (37.6+/-6.6). A total of 57 pigs were born from nine litters. Six litters from sexed sperm (X-sorted) produced 33 females (97%) and one male. Three litters from control transfers produced 23 pigs, 11 of which were female (48%). The sex ratio of the offspring was predicted based on the sort reanalysis of the sorted sperm for DNA content.     

Attempts to overcome the anti-fertility effect of intrauterine plastic spirals in the ewe

A study was conducted to determine whether the antifertilization of intrauterine devices in ewes could be overcome by the use of hormones or drugs that either stimulate or inhibit uterine motility. 44 parous, western ewes were unilaterally ovariectomized, and a plastic spiral was inserted into the uterine horn opposite the remaining ovary. Spirals were immediately removed from 5 ewes. At the time of mating, 2 weeks to 3 months post surgery, sham-operated and spiral control ewes were injected with saline solution. Ewes with spirals were injected with either estradiol, epinephrine, oxytocin, oxytocin and acetylcholine, or oxytocin, acetylcholine, and physostigmine. Other ewes with spirals were laparotomized, and either the uterus was massaged or the cervical lumen was cleaned. 3 days postmating, 8 ova recovered from 5 sham-operated ewes were all cleaved, with a mean of 90 accessory sperm in the zonae pellucidae. 3 of 12 ova recovered from 8 spiral control ewes were cleaved. Only 1 of 40 ova recovered from 28 treated ewes was cleaved. Accessory sperm were not found in either cleaved or uncleaved ova from any spiral ewe. None of the treatments overcame the antifertilization effect of the spiral.     

用去透明带仓鼠卵穿透试验检测牛冷冻精子的受精能力

研究了用去透明带仓鼠卵穿透试验检测牛冷冻精子的受精能力。对36头西门塔尔、23头夏洛来和12头利木赞牛冷冻精子的实验结果表明：三个品种的牛冻精均能穿入去透明带仓鼠卵，并形成发育良好的雄原核。穿透率在70％－80％左右，有原核卵百分率在30％左右。去透明带 鼠卵穿透试验是检测牛冻精受精能力的有效方法。