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Bitch fertility after natural mating and after artificial insemination with fresh or frozen semen
Abstract
The birth rate and fecundity of 92 bitches of 32 different breeds mated naturally or following artificial insemination of fresh or frozen semen were compared. The birth rate after natural service was 92 per cent compared with 84 per cent when fresh semen was deposited in the uterine body. When frozen semen was inseminated intra-uterine a birth rate of 67 per cent was obtained whilst a figure of 25 per cent was obtained following intra-vaginal insemination of fresh semen. There were no differences in litter size.
... Silva et al. [5] reported the decrease of conception rates by 40% as a result of cryopreservation processes in a study carried out on a small group of experimental animals. It has been proven that uterine deposition of frozenthawed semen results in higher conception rates when compared with vaginal insemination [3,4,11,17,49]. Two methods of uterine catheterization have been developed in bitches [2,3,17,47,50]. The Norwegian method of catheterization involves the use of rigid catheters following the manual transabdominal fixation of the cervix, which should be tilted in horizontal position [2,16,17]. ...
... It has been proven that uterine deposition of frozenthawed semen results in higher conception rates when compared with vaginal insemination [3,4,11,17,49]. Two methods of uterine catheterization have been developed in bitches [2,3,17,47,50]. The Norwegian method of catheterization involves the use of rigid catheters following the manual transabdominal fixation of the cervix, which should be tilted in horizontal position [2,16,17]. This technique requires a certain amount of practice and is usually impractical in obese and/or nervous bitches [51]. ...
... Additionally, the risks associated with surgery, anaesthesia, infection, etc. present obvious disadvantages [24]. The conception rates after vaginal deposition of cryopreserved dog semen were usually very poor [3,4,49]. On the contrary, several other researchers [9,10,15,27,28] obtained satisfactory results of vaginal insemination if a high total number of frozen-thawed spermatozoa was deposited into genital tract. ...
One hundred fifty-two bitches of seven breeds were vaginally inseminated with fresh or frozen-thawed semen of 10 stud dogs of respective breeds. The semen was supplemented with prostatic fluid before insemination. In experiment 1 bitches of each breed were randomly assigned to three treatment groups, consisting of 29 females (group 1), 33 females (group 2) and 32 females (group 3). In group 1 bitches were inseminated into vagina with fresh semen using a bovine infusion pipette. In group 2 bitches were inseminated into vagina with fresh semen using the Osiris catheter. In group 3 bitches were inseminated with frozen-thawed semen with the Osiris catheter. The number of sperms in each insemination dose was adjusted to 300 x 10(6). In experiment two bitches were randomly assigned to two treatment groups, consisting of 30 females (group A) and 28 females (group B). In group A bitches were inseminated with fresh semen, whereas in group B with frozen-thawed semen. Osiris catheter was used in both groups. The total number of sperms was adjusted to provide 250 x 10(6) of progressively motile spermatozoa in each insemination dose. In experiment 1 the pregnancy rates/whelping rates were 86.2/82.8%, 81.8/81.8% and 59.4/59.4% for groups 1, 2 and 3, respectively. The differences between group 1 and 3 were statistically significant (p < 0.05). The litter sizes at birth/litter sizes at weaning were 5.8+/-2.3/5.4+/-2.0, 6.3+/-1.4/5.7+/-1.0 and 3.9+/-1.2/3.5+/-1.5 in groups 1, 2 and 3, respectively. The litter size at birth and at weaning was reduced (p < 0.05) when frozen-thawed semen was used for insemination (group 3). There were not significant (p > 0.05) differences in the litter size between groups 1 and 2. In experiment 2 pregnancy rates/whelping rates and litter sizes at birth/litter sizes at weaning were 86.7/86.7%, 60.7/57.1% (p < 0.05) and 6.1+/-1.6/5.7+/-1.7, 4.0+/-1.4/3.8+/-1.4 (p < 0.05) in groups A and B, respectively. This study shows that results of AI with a fresh semen using a bovine infusion pipette and the Osiris catheter are equivalent. The results of the use of the Osiris catheter for vaginal insemination of frozen-thawed dog semen extended with prostatic fluid after thawing are not encouraging. The pregnancy rate, whelping rate and litter size are reduced when frozen-thawed, prostatic fluid-supplemented semen is vaginally deposited using the Osiris catheter.
... Triladyl® contains Tris, citric acid, fructose, glycerol, tylosin, gentamycin, spectinomycin and lincomycin (Triladyl, Minitüb Gmbh, Tiefenbach, Germany). Dog semen freezes well in an extender containing Tris, egg yolk, glycerol, citric acid and fructose and has high fertility (Andersen, 1976, Farstad, 1984, Ferguson et al., 1989, Theret et al., 1987). An overall pregnancy rate of 80% was obtained in Nöthling and Volkmann's trial (1993). ...
... a) Intrauterine insemination using frozen-thawed semen 34 U Un ni iv ve er rs si it ty y o of f P Pr re et to or ri ia a e et td d – – S Sh hu ut tt tl le ew wo or rt th h, , R R ( (2 20 00 05 5) ) U Un ni iv ve er rs si it ty y o of f P Pr re et to or ri ia a e et td d – – S Sh hu ut tt tl le ew wo or rt th h, , R R ( (2 20 00 05 5) )Tsutsui et al. 1989, Silva et al. 1996 Farstad, 1984; Ferguson et al. 1989 b) Intravaginal insemination using frozen-thawed semen U Un ni iv ve er rs si it ty y o of f P Pr re et to or ri ia a e et td d – – S Sh hu ut tt tl le ew wo or rt th h, , R R ( (2 20 00 05 5) ) U Un ni iv ve er rs si it ty y o of f P Pr re et to or ri ia a e et td d – – S Sh hu ut tt tl le ew wo or rt th h, , R R ( (2 20 00 05 5) ) Two studies failed to show an effect of insemination route (intravaginal vs intra-uterine) upon the fertility of frozen-thawed dog sperm (Silva et al. 1996; Rota et al. 1999). However, in a retrospective study by a significantly higher pregnancy rate and litter size was shown for intrauterine insemination using the Norwegian catheter (NIU) (Andersen, 1975) as compared to intravaginal insemination (VAG) or semen inseminated intrauterine with the aid of fibreoptic endoscopy (EIU). ...
Thesis (DMedVet (Gyn))--University of Pretoria, 2002. Includes bibliographical references.
... For artificial insemination (AI) of dogs, fresh semen [3,12,18,20,21], cooled semen [6-9, 12, 15], and frozen semen [3,12,16,19] have been investigated. We have shown that when using fresh semen, 2 × 10 8 sperm [21] are required for intravaginal insemination and 1 × 10 7 sperm [20] are required for unilateral uterine horn intrauterine insemination. ...
... For artificial insemination (AI) of dogs, fresh semen [3,12,18,20,21], cooled semen [6-9, 12, 15], and frozen semen [3,12,16,19] have been investigated. We have shown that when using fresh semen, 2 × 10 8 sperm [21] are required for intravaginal insemination and 1 × 10 7 sperm [20] are required for unilateral uterine horn intrauterine insemination. ...
Cooled canine semen solutions for storage were investigated with three stock solutions: egg yolk-citrate-glycine-glucose solution, egg yolk Tris-fructose citrate solution (EYT-FC), and egg yolk sodium citrate dihydrate solution (EYCD). For the control group, the second fraction of semen was examined. Nine male beagles and 37 female (47 experimental cases) beagles for artificial insemination (AI) were used. The qualities of semen stored at 4 degrees C deteriorated earlier in the control and EYCD groups. In the other two groups, sperm motility was 60% or higher after storage for 6 days and 20% or higher after storage for 12 days. On a comparison of these two groups, the sperm motility and viability were slightly higher in the EYT-FC group. A high conception rate was obtained by AI using semen stored at a low temperature for a maximum of two days in the control group and four days in the EYT-FC group.
... Artificial insemination with fresh or frozen-thawed ejaculated spermatozoa has been used widely and successfully in canines [4,5,11,12,15,18]. Various methods of insemination are presently available to the inseminator, including intrauterine insemination with laparotomy [6,16], the Norwegian catheter [1], fiber optic endoscopy [2], or intravaginal insemination [4,5,15,20]. ...
... Artificial insemination is considered to be an in vivo assay of spermatozoa survival and is the most definitive test of sperm function. Artificial insemination with fresh or frozen-thawed ejaculated spermatozoa has been used widely and successfully in canines [4,5,11,12,15,18]. Various methods of insemination are presently available to the inseminator, including intrauterine insemination with laparotomy [6,16], the Norwegian catheter [1], fiber optic endoscopy [2], or intravaginal insemination [4,5,15,20]. ...
The present study was performed to assess the fertility of frozen-thawed dog semen prepared by freezing with 6% glycerol and thawing at 70 degrees C for 8 sec, and to evaluate the least number of post-thaw spermatozoa necessary to achieve pregnancy by intrauterine or intratubal artificial insemination. It was found that the pregnancy rate of intrauterine artificial insemination was 100% using 6% glycerol buffer and thawing at 70 degrees C for 8 sec with 5 x 10(7) spermatozoa. Even though the pregnancy rate (80%) and the whelping rate (24.5%) in the 5 x 10(6) spermatozoa inseminated group were lower than those of the 5 x 10(7) spermatozoa group, conception was confirmed with 5 x 10(6) spermatozoa. Although the pregnancy rate of intratubal insemination was low (20%) with 4 x 10(6) spermatozoa, this study is the first report to show the pregnancy rate of intratubal insemination with frozen-thawed ejaculated canine semen. In order to improve the pregnancy rate with intratubal insemination of canine spermatozoa, it is necessary to investigate the optimal insemination site of the uterine tube, the appropriate number of sperm, and the direct effect of buffer on oocytes.
... This indicates high fertility, but in the study by Conze et al. (17), only a small population of bitches was examined, which limits the strength of their conclusions. These numbers have to be compared to normal pregnancy rates, which are between 78 and 97% (19)(20)(21). ...
This study evaluated fertility in canines after cesarean section and compared it with natural parturition. Parameters, such as the time of the next heat after the first parturition or cesarean section, the heat which was used for another breeding attempt, whether it was successful, the number of puppies that were born, and the necessity of another cesarean section were examined. The study relied on questioning patient owners at a University clinic. A Google online form was also used. Information for 261 dogs from different breed groups was included, of which 119 bitches were in the cesarean section group, and 142 were in the natural parturition group. In total, 93 ± 2.7% [LSMeans ± standard error (SE)] and 91.12 ± 3% (LSMeans ± SE) of the bitches became pregnant after cesarean section and natural parturition at the first breeding attempt. There was no significant effect on the breed group or whether the bitch had undergone a cesarean section before (p = 0.8 and p = 0.63). Bitches, which underwent a cesarean section, were more likely to have further cesarean sections performed (p < 0.001). However, neither the breed groups (p = 0.17), whether the bitch had undergone a cesarean section (p = 0.59), nor the number of previous parities had any effect on the number of puppies born (p = 0.95). The breed group bulldogs had a high proportion of cesarean sections. Only 42.11% of the bulldogs had a natural parturition as the first included parturition and only 31% gave birth naturally thereafter.
... As the length of diestrus can vary in one bitch, depending on whether she is pregnant or not, it was assumed that these bitches were not suffering from hypoluteoidism but did not become pregnant for other reasons. The finding that 20% of bitches did not become pregnant is in accordance with average pregnancy rates after a combination of natural mating and insemination [41,42]. This proportion therefore did not raise suspicion that a high number of the included nonpregnant bitches reabsorbed due to pathological conditions. ...
Pregnancy and lactation are amongst the most challenging times of a bitch’s life. Most studies focusing on the endocrinological aspect of pregnancy consider only a small number of animals. The aim of this study was to evaluate progesterone (P4) concentrations in a large number of bitches during early, mid and late pregnancy. In total, 126 bitches of various breeds were recruited following a thorough clinical and gynecological examination during estrus. Blood samples were collected three times (T1–T3) during pregnancy or from non-pregnant dogs in diestrus, and P4 was measured via chemiluminescence. At T1 (11–19 days post-ovulation (dpo)), serum P4 concentrations were 30.23 ± 6.65 ng/mL and 28.45 ± 6.26 ng/mL, at T2 (23–32 dpo) they were 22.73 ± 6.27 ng/mL and 22.59 ± 5.77 ng/mL and at T3 (52–60 dpo) they were 6.68 ± 2.18 ng/mL and 3.17 ± 2.26 ng/mL, in pregnant (n = 98) and non-pregnant (n = 23) dogs respectively. The P4 concentrations differed significantly between pregnant and non-pregnant animals at the last examination (p ≤ 0.001). In the context of hypoluteoidism, the gathered data yielded interesting results. Overall, 28 out of 98 pregnant bitches showed a greater decline (>15 ng/mL) in P4 concentrations from early to mid-pregnancy, and 56 bitches showed P4 concentrations lower than deemed adequate (>20 ng/mL at T1 and T2, >5 ng/mL at T3) according to existing recommendations. Despite not being supplemented with P4, none of those animals suffered from abortion or preterm delivery. Considering that supplementation of P4 can entail considerable risks for the bitch and the puppies, more research on P4 concentration patterns, diagnosis of hypoluteoidism and treatment indications and options is indicated.
... C ooled semen from dogs has allowed a relatively inexpensive, simple, and successful method to the increasing demand of semen transport for the development of purebred dogs, 1 to satisfy demands of private owners and for preservation of endangered canids. 2 This semen cryopreservation method has been often used instead of frozen-thawed semen due to easy handling and higher pregnancy and whelping rates. 3,4 Cryopreserved semen may be sent for longer distances or kept for more than 2 days before artificial insemination, 5,6 or even be main-tained for long-term storage. [7][8][9] In Europe, the artificial insemination percentages performed in dogs using fresh, chilled, or frozen-thawed semen are 50%-55%, 10%, and 35%-40%, respectively. ...
Seminal plasma has several components that protect the sperm cells and assist in the fertilization process. In contrast, the exact role carried out by seminal plasma during the cooling of canine semen remains controversial. Moreover, concerning the long estrus period, the possibility to store chilled semen at 5°C for more than 72 hours and maintain good sperm quality for additional inseminations could increase fertilization rates. Thus, this study aimed to evaluate the seminal plasma influence on quality and oxidative stress of the extended canine semen stored at 5°C for 7 days. Three ejaculate pools from eight healthy dogs were collected by digital manipulation of the penis. The sperm kinetics, sperm vitality (eosin/nigrosin stain), integrity of plasma and acrosomal membranes, morphology, superoxide and hydrogen peroxide production, mitochondrial potential, lipid peroxidation, and oxygen reactive species production (induced and spontaneous thiobarbituric acid [thiobarbituric acid reactive substances, TBARS] assay) were evaluated every 48 hours (M0, M48, M96, and M168) until 7 days (168 hours) in cooled extended (TRIS egg yolk) semen of dogs at 5°C with (+SP) or without (-SP) autologous seminal plasma. No statistical difference was found for sperm kinetics in cooled samples with +SP and -SP during the experimental time period, except for the progressive motility of +SP samples that was higher at M48 than M96 (p = 0.023). The seminal plasma did not influence any other evaluated sperm characteristics. Finally, our results demonstrated that the presence or lack of seminal plasma during cooling the semen of dogs does not influence sperm quality at 5°C. Moreover, the components of the semen extender may contribute to maintaining good sperm quality and low reactive oxygen species production during the long period of the dog's semen cooling, even after semen centrifugation.
... The fertility results of inseminations using frozen semen are good, although the degree of success is dependent on the site of insemination (i.e. intracervical or intra-uterine; Farstad, 1984). Cat semen was first cryopreserved in 1978 and used in artificial insemination experiments. ...
A new protocol for the cryopreservation of mouse spermatozoa was developed for the CBA strain. With the aid of a cryomicroscope, several cryoprotectants were screened. The glycerol concentration and osmolarity of an egg yolk TES/Tris diluent resulting in optimal cryoprotection were 1.25% and 675 mOsm respectively. The optimal rate of cooling was 50°C/min from 4°C to -70°C. The percentage of motile sperm following cryopreservation in the modified diluent was assessed subjectively as 55 ± 7.4% Acrosome integrity was investigated on permeabilized cells using a specific monoclonal antibody to the acrosome. The proportion of acrosome-intact spermatozoa after freezing and thawing was 55 ± 13%. The developed protocol was transferred to a cell freezer and the diluent was further modified by the inclusion of 0.1% sodium lauryl sulphate which facilitated recovery of frozen-thawed spermatozoa. This diluent was designated Mouse Sperm Cryoprotectant (MSC). Incubation of oocytes with frozen-thawed spermatozoa resulted in 51% developing to the 2-cell stage, of which 67% developed to the morula/blastocyst stage. Transfer of 2-cell stage embryos to the oviducts of pseudopregnant recipients resulted in a total implantation rate of 39%, with 16% developing to fetuses. Replacement of 2-cell stage embryos to the oviducts of pregnant recipients resulted in 17% developing to live offspring. Further experiments with cryopreserved oocytes and cryopreserved sperm from two strains of mice, CBA and (C57blxCBA) F1, resulted in fertilization rates of 5% and 13% respectively. Transfer of 2-cell stage embryos from oocytes fertilized with CBA and F1 cryopreserved spermatozoa to pseudopregnant recipients resulted in implantation rates of 67% and 92%, with 22% and 25% developing to fetuses respectively. This protocol, employing a novel cryoprotectant, will provide a consistent and reproducible method for preserving valuable strains of mice.
... Majority (97.1%) of the kennels used a stud either from within their own stock or from other breeders for mating and only one kennel used artificial insemination (AI). There was no significant association between method of mating and adult morbidity and mortality which was similar to the study findings of Farstad, (1984). However, this was not in agreement with studies by Linde Forsberg, (2005a) and Farstad, (2010) who reported that artificial insemination (AI) prevented the spread of sexually transmitted diseases such as Brucella canis or Herpes virus. ...
Kennels provide dogs for security and for companionship; however, management errors can lead to increased susceptibility to infections hence an increase in morbidity and mortality within the populations. A cross-sectional study of 35 kennels was conducted in Nairobi, Kenya to determine the effect management practices have on the occurrence of diseases in kenneled adult dog populations. The management practices examined were hygiene, type of housing, type of beddings, provision of heat, food types, provision of veterinary services, deworming practices, ectoparasite control methods, quarantine and euthanasia protocols and methods for diagnosis of diseases. Food types (P=0.006) and ectoparasite control methods (P=0.008) were found to be the strongest independent management factors for morbidity and mortality of the kenneled adult dog population respectively. These management risk factors should be considered by kennel owners when developing disease management programs for their dogs to easily alleviate avoidable morbidities and mortalities.
... This could be because majority of the dog breeders practiced natural mating. Natural mating has been found to produce higher birth rate than artificial insemination (Farstad, 1984). However, conducting artificial insemination twice with optimal timing has been reported to yield a higher whelping rate (Thomassen & Farstad, 2009). ...
Dog breeding business has the potential to reduce unemployment among youths, especially fresh graduates of veterinary medicine. This study attempted to determine factors associated with making profits in dog breeding business in Ibadan, Oyo state, Nigeria. A semi-structured self-administered questionnaire was used to obtain information on demographic and management factors, tangible and intangible indicators of profitability in dog breeding. A criterion was designed to qualitatively define profitability in dog breeding. Descriptive statistics, univariate and multivariable analyses were done to determine predictors of profitability in dog breeding business. The mean age of respondents was 32.1 ± 7.7 years. The median year of practicing dog breeding was 6 (range 0 to 25). Using our profitability criterion, of the 70 dog breeders, only 13 (18.6%) was adjudged to have made profits from dog breeding business. In the univariate analysis, years of experience as a dog breeder (Odds Ratio (OR) = 6.4; 95% Confidence Interval (CI) 1.2 – 64.6), bitch becoming pregnant at every mating (OR = 6.5; 95% CI 1.5 – 40.9), the total number of dogs in the kennel (OR = 4.4; 95% CI 1.0 – 20.1) and going on vacation by breeders (OR = 4.1; 95% CI 1.0 – 20.5) were significantly associated with profitability in dog breeding. In the multivariable logistic regression, variables such as the bitch becoming pregnant at every mating (OR = 7.5; 95% CI 1.5 – 38.1), years of experience as a breeder (OR = 7.9; 95% CI 1.3 – 48.1), feed type (OR = 5.2; 95% CI 1.0 – 27.2) and having a University degree (OR = 10.2; 95% CI 1.0 – 106.0) were significant predictors of profitability in dog breeding business. Potential dog breeders should consider these factors before venturing into dog breeding business.
Keywords: Dog breeding, Education, Feed type, Profit, Oyo state, Veterinary medicine
... Artificial insemination can be used to determine fertility in vivo and has been widely and successfully used in many mammalian species (Chandler, 2000;Januskauskas et al., 1999;Nakatsukasa et al., 2001;Pursel et al., 1972;Pursel and Johnson, 1975;Vicente and Viudes-de-Castro, 1996). Artificial insemination with fresh and frozen-thawed ejaculated spermatozoa has been used widely and successfully in canines (Farstad, 1984;Farstad and Andersen Berg, 1989;Linde-Forsberg andForsberg, 1989, 1993;Nöthling, 1995;Seager et al., 1975;Thomassen et al., 2001). ...
... In the dog and fox, straws are generally preferred over pellets for easier identification and less chance of contamination (Farstad, 1996). Straws are often placed on a rack that is just above the level of liquid nitrogen to freeze (Farstad, 1984). ...
... Frozen canine semen can be stored practically indefinitely, and the techniques and extenders for dog sperm cryopreservation developed in recent years have resulted in postthaw motility of up to 70% [1,2] and whelping rates of up to 85% [3][4][5]. However, pregnancy rates and whelping rates are generally lower with frozen semen than with chilled, extended semen, when the same optimal methods are used for AI [6,7]. It is technically easier to chill than to freeze semen, and the shipment of chilled semen is less expensive and regulations for import and export are often less complicated than for frozen semen. ...
The use of chilled, extended semen in dog breeding is becoming increasingly popular as preparation and transportation is less expensive and regulations are often less complicated than for frozen semen. Sugar is one of the main constituents in semen extenders, and glucose and fructose are metabolized in separate pathways by freshly ejaculated dog sperm. In this study, glucose, fructose or an equal mixture of both were used in an egg-yolk-tris (EYT) extender at two different concentrations (10 and 70 mM). EYT extender without sugar supplementation, providing only the glucose (3-4 mM) originating from the egg-yolk, served as a control. The longevity of the chilled semen at 5 degrees C was 23 days: the quality of physical and functional characteristics decreasing with time. Glucose and fructose had a strong influence on motility and movement patterns of chilled canine semen. The beneficial effect of 70 mM sugar concentrations compared to 10 mM and the control was pronounced, and maintained sperm motility > or = 70% for 8 days of storage, compared to for 4 days in the control extender. Fructose maintained higher sperm motility than did glucose and the mixture. VAP values were higher in sugar-supplemented extenders (P < 0.05). Neither type nor concentration of the two sugars influenced sperm plasma membrane, acrosome integrity or the acrosome reaction following ionophore challenge (ARIC). Sugar consumption by dog sperm varied between the different periods of storage and with sugar concentrations provided in the extenders. Glucose consumption by dog sperm was greater than fructose consumption when both sugars were present in equal amounts, indicating that dog sperm used glucose in preference to fructose. In conclusion, the major influence of the two sugars on chilled semen was to support motility. EYT extender supplemented with fructose at a concentration of 70 mM was found to be the best of the tested extenders for long-term preservation of chilled canine semen.
... The domestic canine (Canis familiaris) is generally known to be a fertile species, with !85% pregnancy rates reported under controlled natural mating conditions [1][2][3][4]. ...
Transcervical insemination (TCI) has generated recent interest as an assisted reproductive technique in the dog. A case series study was performed to determine if TCI using frozen-thawed semen was a viable technique to offer in a general veterinary practice setting. Over a period exceeding 28 months, 137 Greyhound bitches were presented for assisted breeding. A single, timed insemination using a rigid cystoscope to aid in transcervical deposition of a frozen-thawed semen dose was given within 72 h after the behaviorally estrual bitch had a > 4 ng/mL serum progesterone concentration and estrus-categorized vaginal cytology. Litter size, pregnancy and whelping rate were collected; their association to semen center and stud dog were quantified. Of the 137 bitches, 117 were bred for one cycle and 20 were bred for two or more cycles, giving a total of 161 single, timed inseminations. Pregnancy rate was 89.4%, with 141 (87.5%) whelping. Litter size was 6.9+/-2.7 (mean+/-S.D.) pups. Semen center (P=0.84) and stud (P=0.79) had no effect on pregnancy. These results were quite favorable when compared to prior TCI studies, and are possibly due to the use of a single breed (i.e., Greyhound) with good fertility. This study supported the application of TCI, in Greyhounds, as a successful and viable service to offer in private practice. Additionally, these results have value in their use for benchmarking future breed-specific and TCI research. Serendipitously, the apparent fecundity results obtained in this observational study suggests a possible greater appreciation be given to breed composition and choice in assisted reproductive technique studies.
... Since the work of Anderson in 1975 [1], it was accepted that frozen-thawed dog sperm should be inseminated into the uterus in order to obtain good fertility. Uterine insemination poses practical problems because it either requires one to pass a pipette through the cervix, which is sometimes impossible to achieve [2] and [3], or expensive fiber-optic equipment with which to catheterize the cervix under visual control [4], or surgical or laparoscopic exposure of the uterus [5] and [6]. Vaginal insemination, in contrast, is easy, requires simple, cheap, readily available equipment, and may be repeated over a number of days if necessary to ensure insemination at the time when the oocytes are fertilizable [7]. ...
Although dog prostatic fluid decreases the longevity of ejaculated dog spermatozoa, it also increases their rate of motility and their fertility after vaginal insemination, as well as the fertility of epididymal spermatozoa after uterine insemination. These findings indicate a need to further characterize the effects of prostatic fluid on dog spermatozoa. This study was done to determine the effects (P<0.05) of homologous prostatic fluid added prior to cooling, after thawing, or at both times to epididymal spermatozoa from 21 dogs. The effects of two extenders were also determined. The one extender was Biladyl(*) with Equex STM paste(**) (BilEq) and the other Andromed(*) (Minitüb, Tiefenbach, Germany (*); Nova Chemical Sales, Scituate, MA, USA (**)). The response variables were percentage progressively motile spermatozoa (Prog) and morphology after thawing. Prog was measured at various times until 8h after extension (unfrozen spermatozoa) or until 2h after thawing. Prog after thawing was higher with BilEq than Andromed, when no prostatic fluid was added prior to cooling, and when prostatic fluid was added after thawing. BilEq resulted in a higher mean percentage of spermatozoa with bent principle pieces than Andromed and the addition of prostatic fluid prior to cooling resulted in lower mean percentages of cytoplasmic droplets and bent principle pieces than when none was added. The optimal combination was BilEq with prostatic fluid added prior to cooling (in order to inhibit the development of bent principle pieces) and after thawing (to achieve higher motility until 1h after thawing). This study shows that BilEq is more suitable for the freezing of epididymal spermatozoa than Andromed and that prostatic fluid improves the freezability and post-thaw longevity of epididymal spermatozoa frozen in BilEq.
A number of methods are currently used to predict the optimal date of insemination of the breeding bitch, particularly with the use of frozen–thawed canine semen which has a far shorter lifespan than fresh semen. Aside from confirming cytological oestrus, vaginal cytology is of no assistance in predicting the most fertile day(s) in a bitch; however, a neglected avenue of research suggests that vaginal cytology may be of great importance in confirming the days of optimal fertility retrospectively. Similarly, vaginoscopy provides clues as to the stage of a bitch's cycle but is inadequate as a sole determinant of her most fertile days. Nevertheless, vaginoscopy is useful to identify very late oestrus and the onset of dioestrus, as well as Stage I of labour (cervical dilatation). Due to variations in the rate at which circulating progesterone concentrations rise in individual bitches, the reliability of circulating progesterone concentrations for determining the optimal day(s) of insemination with frozen–thawed semen decreases as values rise. Moreover, progesterone assay results can vary widely due to extrinsic factors such as the time of blood sampling, sample storage conditions and the assay employed. Finally, this review investigates evidence surrounding various insemination routes and suggests that well‐performed vaginal insemination, even with frozen–thawed semen, may be an acceptable approach for cases where transcervical insemination is impractical.
This study was undertaken to determine the conception rates after artificially inseminating Philippine native bitches with frozen-thawed canine semen on the first day of estrus (single insemination) or first and fifth days of estrus (double insemination). Semen was collected by digital manipulation from an apparently healthy Rotweiller stud. The collected semen was subjected to gross and microscopic examination to determine its viability for freezing and insemination. Only semen with motility rate of 60% or higher was frozen using a Tris-raffinose-eggyolk extender containing glycerol as cryoprotectant. The frozen semen was stored in liquid nitrogen until use. Frozen-thawed semen with a motility rate of 30% or higher was then artificially inseminated into the vagina of adult Philippine native bitches. Sixteen apparently healthy native Philippine bitches were assigned into two treatment groups. Half of the bitches were inseminated only once at the first day of estrus or twice on the first and fifth days of estrus. Heat detection was based on clinical signs and examination of vaginal smears. This study yielded 25% conception rate for single insemination and 50% conception rate for double insemination of frozen-thawed canine semen. All the pregnant bitches were allowed to whelp producing healthy puppies. Based on available literature reviewed, this is the first report on the successful artificial insemination of Philippine native bitches using frozen-thawed canine semen. However, based on the results of this study, further research on optimizing the canine freezing protocol, number and timing of insemination and other factors affecting semen quality are warranted.
This study was carried out to determine the effect of transcervical and intravaginal artificial insemination on the pregnancy rate in dogs. Semen was collected by the massage method from dogs brought to our department. Collected semen was examined in the laboratory and stored in liquid nitrogen after dilution with Tris extender. During the study 31 bitches brought to our department for artificial insemination were used. One of the bitches was not evaluated. Oestrus was detected by vaginal cytology and the bitches were inseminated twice during the oestrus period. Fifteen of the 30 bitches were inseminated transcervically and the other 15 intravaginally. The pregnancy rate was 60.00% with the transcervical insemination method and 26.66% with the intravaginal insemination method (p < 0.05). In conclusion, we have detected that transcervical insemination with frozen dog semen is more effective than intravaginal insemination in terms of fertility.
Cryopreservation induces detrimental effects on spermatozoa affecting their longevity and fertilization capacity. The aim of this study was to evaluate the potential cryoprotective effect on the post-thaw canine sperm quality of different protein fractions from seminal fluid (FS) added to freezing medium. Ejaculates collected from 3 Golden Retriever dogs. In each experimental trial (n= 12) was used a sperm pool which was divided into 4 groups and diluted in a freezing extender (fructose, citric acid, glycerol, egg yolk). Control medium (C) was supplemented with Equex STM and three groups supplemented with different SP protein fractions: Group I (<10kDa), Group II (<30kDa) and Group III (<100kDa). Post-thaw sperm quality was evaluated according to: motility with propidium loduro, viability (PI), plasmatic membrane integrity with SYBR-14/PI, ex-temalization of phosphatidylserine with Annexin-V and acro-some status with CTC-PI. Differences among groups were just evident only for motility (P<0.05). It was higher in Control and Group III (44.8 and 40.6%) than groups I and II (27.6 and 16.3%). The SP-protein fractions added to freezing extender did not improve substantially the post-thaw sperm quality of frozen-thawed dog semen.
The objective of this retrospective clinical study was to compare pregnancy rates obtained after the use of endoscopic-assisted transcervical catheterization (EIU) or laparotomy (SIU) for insemination of frozen-thawed dog semen. Healthy bitches from various breeds were inseminated with semen from multiple donors processed by different freezing centers. Data from 118 inseminations (78 EIU and 40 SIU) performed between 2009 and 2011 were analyzed. Insemination timing was based on vaginal cytology, serum progesterone concentrations, and vaginoscopy. A ureterorenoscope and a CH-5 Transcervical insemination catheter were used for EIU; 28 of the bitches in this group were inseminated twice with the second insemination less than 12 hours after the first. The numbers of live morphologically normal sperm (LMNS) were determined to characterize insemination doses. Overall, pregnancy rate was greater (P < 0.05) in the EIU group (65%) than in the SIU group (45%). Pregnancy rates were greater (P ≤ 0.06) when more than 100 × 10(6) LMNS were inseminated regardless of insemination method; the greatest pregnancy rate was observed in the EIU group when this insemination dose was used (38/49; 78%). There was no significant difference in pregnancy rate whether one (69%) or two inseminations (64%) were performed in the EIU group. Complications in the SIU group included anesthetic-induced bradycardia during surgery, significant postsurgery pain, seroma formation over the abdominal incision, and delayed wound healing. No complications were noted during or after insemination in the EIU group. In conclusion, these results support the use of EIU as a noninvasive alternative to laparotomy for insemination of frozen-thawed dog semen. In addition, use of more than 100 × 10(6) LMNS is also recommended for insemination.
(1) To report whelping rates and litter sizes following coeliotomy-assisted intrauterine inseminations (CAII) performed commercially and (2) to identify factors that may influence these outcomes.
Retrospective single cohort observational study.
All oestrous cycles in bitches that presented to the study hospital for CAII between 1 January 2005 and 31 December 2010 were included. One insemination was performed per oestrus. Whelping and litter size following CAII were recorded. Potential determinants of these outcomes were assessed.
Of 238 inseminations performed, 174 (73.1%) resulted in whelping. The known litter size ranged from 1 to 16 pups (mean ± SD 6.12 ± 3.12 pups). From univariable analyses, progressive motility percentage was the only variable significantly associated with odds of whelping (P = 0.020); bitch parity and weight were associated with litter size when adjusted for each other (P = 0.035 and 0.003, respectively). Inseminations performed with >200 × 10(6) progressively motile sperm were more likely to result in whelping relative to inseminations with >100-200 × 10(6) progressively motile sperm (odds ratio 3.61, 95% confidence interval 0.84-15.5, P = 0.084), and, in a separate model, relative to >75-125 × 10(6) progressively motile sperm (odds ratio 6.09, 95% confidence interval 1.41-26.36, P = 0.016).
Whelping rates and litter sizes were similar to other case studies and the experimental reports of CAII. Progressive motility percentage affects the odds of whelping, and litter size is affected by both the weight and parity of the bitch. Importantly, these findings provide some evidence that whelping rates with CAII are not maximised unless more than 200 × 10(6) progressively motile sperm are inseminated.
Canine semen was obtained by digital manipulation from two donor dogs and twelve stud dogs. The sperm-rich fraction was diluted with either of two different diluents and the survival of spermatozoa before and after freezing was determined. It appeared that there was no difference in the post-thaw survival rate in either of the diluents used.
Resumen: La Inseminación Artificial (IA) en caninos es una práctica que brinda grandes beneficios en la clínica reproductiva diaria. Esta biotecnología puede ser de moderada o alta complejidad, de bajo o mediano costo, según la técnica y el tipo de semen (fresco, refrigerado o congelado) utilizado. En cada caso brinda diferentes posibilidades, otorgando siempre grandes beneficios en la reproducción canina. Si se extrae semen de buena calidad, se lo acondiciona y maneja adecuadamente, se realiza la IA en el momento oportuno y se aplica la técnica adecuada, se pueden obtener porcentajes de fertilidad muy alentadores. Sin embargo, si los factores mencionados no son adecuadamente controlados puede tornarse una práctica des-alentadora. La aplicación de IA con semen criopreservado aumentará las posibilidades de desarrollo del profesional veterinario en nuestro país. Abstract: Artificial insemination in dogs is a technique with great potential in clinical repro-duction. This biotechnology can be implemented with moderate or high complexity and with low or medium cost depending the technique and the type of semen used (fresh, chilled, frozen). In any case it can produce great benefits to canine reproduction. If good semen quality is obtained, and it is properly handled and artificial insemination is done at the right time, the pregnancy resulted could be very encouraging. However if those factors are not properly controlled the results obtained could be very discouraging. The use of artificial insemination with frozen semen will increase the professional development of the veterinar-ians in our country.
Contents
This study assessed the effects of different incubation temperatures on semen viability and the influence of pooling on semen longevity. In experiment 1, semen samples were collected from five dogs, individually processed (individual semen: IS) and then aliquots from each male were pooled (pooled semen: PS). Semen samples (IS and PS) were diluted in a Tris‐glucose‐yolk extender and preserved as fresh (37 and 25°C) and chilled semen (4°C). Sperm motility and the percentages of sperm abnormalities and acrosome membrane integrity were assessed for 24 h. Storage at 25 or 4°C for the first 24 h yielded similar semen quality, but incubation at 37°C caused drastic reduction in sperm motility from 8 h of incubation onwards. In experiment 2, the semen was processed in the same way to that of experiment 1 and then preserved at 25 or 4°C until semen inactivation. Semen that was incubated at 25°C became completely inactive after 3–4 days of storage, while semen that was preserved at 4°C presented with more gradually decreased sperm motility (mean values of 40–60% for the first 8 days). In addition, the mixing of semen was only observed to influence the sperm quality of the samples stored at 4°C. In experiment 3, semen was collected from five dogs, pooled and frozen in liquid nitrogen; after thawing, it was preserved at 37, 25, 15 and 4°C, and the sperm quality was defined. The motility of the freeze‐thawed semen samples decreased quickly in the first 4 h after thawing, regardless of the preservation temperature of the thawed semen. This study confirmed that semen preserved at 37°C should be used within a maximum of 12 h, while the semen stored at 25°C shows acceptable quality for 24 h. Chilled semen presented highest most sustainable quality, especially when semen is processed as pooled semen.
Die Künstliche Besamung (KB) besitzt beim Nutztier schon lange Zeit eine große Bedeutung. Beim Hund hat sich die KB bis jetzt noch nicht durchgesetzt. Dies liegt zum Teil an dem Reglement der nationalen Hundezuchtverbänden und Vereinen, die den Einsatz der Besamung ablehnen oder stark reglementieren. Aus der Erfahrung mit anderen Tierarten kann man aber erwarten, dass sich langfristig auch beim Hund die KB durchsetzten wird. \\
Ziel dieser Arbeit war es, den momentanen Stand der Wissenschaft auf allen Teilgebieten der KB beim Hund aufzuzeigen. Dazu zählen die Spermagewinnung und- untersuchung, die Möglichkeiten der Samenkonservierung, die Bestimmung des optimalen Besamungszeitpunktes bei der Hündin und die Techniken der Sameneinführung. \\
Im zweiten Teil der Arbeit werden zwei Lernfälle als CASUS-Programm zur Aus-, Fort- und Weiterbildung von Studenten der Tiermedizin und praktischen Tierärzten präsentiert. CASUS-Lernfälle stellen eine Form des E-Learnings dar, das der reinen Wissensvermittlung und Wissensüberprüfung dient. Hier sollte ein Lernfall die Teilschritte der KB auf der männlichen Seite (Spermagewinnung, -untersuchung und -konservierung) erklären, der zweite Lernfall beschäftigt sich mit der Bestimmung des optimalen Besamungszeitpunktes und der Technik der Sameneinführung beim weiblichen Tieren.
Artificial insemination (AI) and semen freezing have become services available to dog owners worldwide, and the demand for services to freeze semen is increasing. In other canids such as the fox, the fur industry utilizes fresh or frozen semen to artificially inseminate vixens to produce pelts. Clearly, AI facilitates the use of a male to sire several females by diluting the ejaculate, increases breeding hygiene, and allows crossing between species with slightly different breeding seasons. The African wild dog (Lycaon pictus) is currently considered by the World Conservation Union (IUCN) as one of most endangered canids. In captive populations of African wild dogs, semen has been frozen with encouraging results, using a standard cryopreservation protocol for domestic dogs, but successful AI has not been reported. In wolves, there is one report regarding the live birth of an offspring after intravaginal AI of a deslorelin-induced estrous female. In 2005, three Mexican gray wolf females were artificially bred by intrauterine insemination with freshly collected semen from unrelated males, and all females whelped. Artificial insemination may be vaginal, intrauterine or intratubal, and the semen may be fresh, fresh and chilled (diluted), or frozen-thawed, and the source of semen may be epididymal or ejaculated. In the domestic dog, the results are good to excellent for AI with all three types of processed semen when the source is ejaculated semen, whereas epididymal sperm still yields poorer results. Species differences in female physiology, as well as differences in the cryotolerance of the sperm from various canid species, warrant further research and development.
Assisted reproductive technologies in dogs began as early as the 18th century. The first scientifically recorded artificial insemination (AI) was performed in Italy by Spallanzani and lead to the birth of three pups. Progress in the area was slow, and subsequent development included AI equipment and methods for short-term preservation of fresh, and later, for frozen semen which led to the world's first litter produced from frozen semen in 1969. Improvement of freezing methods and AI equipment from 1970 onwards has rendered AI useful as a breeding technique for dogs. In parallel, AI in foxes was developed in Scandinavia in the early 1980's; this resulted in the economically valuable crossbreeding of silver and blue foxes for the production of bluefrost pelts. Unfortunately, due to the particular physiology of the canine female, progress in other artificial breeding techniques has lagged behind. Only in the last few years have these techniques been successfully applied in basic research to study oocyte maturation, in vitro fertilization, embryo cryopreservation and embryo transfer in canids.
From 1994 to 2003, a total of 526 bitches of 99 different breeds were artificially inseminated in 685 estrus cycles with domestic (n = 353) or imported (n = 332) frozen-thawed semen from 368 males. The overall whelping rate was 73.1% and mean (+/- S.E.M.) litter size 5.7 +/- 0.1 pups. The whelping rate was higher after intrauterine insemination (75.0%; n = 665) than after intravaginal insemination (10.0%, n = 20; P < 0.05). Insemination at the optimal time resulted in a higher whelping rate (78%, n = 559; P < 0.01) and larger litter size (5.8 +/- 0.2; P < 0.05) than inseminations performed late or too late (55.7% and 4.5 +/- 0.5, n = 61). Two inseminations (n = 384) yielded a higher whelping rate (P < 0.05) and mean litter size (P < 0.01) than one insemination (n = 241), 78.1% and 6.0 +/- 0.2 and 70.5% and 5.1 +/- 0.2, respectively. For inseminations performed at the optimal time, however, the whelping rate was not significantly different for bitches inseminated twice (79.3%, n = 358) versus once (76.8%, n = 168), but the litter size was larger (6.0 +/- 0.2 and 5.3 +/- 0.3). Semen classified as of poor quality (progressive motility < 50% or percentage abnormal sperm > 20%) resulted in a lower whelping rate (P < 0.01) than semen classified as of good quality (progressive motility > or = 50% and percentage abnormal sperm < or = 20%), 61 and 77%, respectively. Small breeds (n = 50) had a smaller litter size (3.9 +/- 0.3; P < 0.01) than larger breeds (medium [5.7 +/- 0.3, n = 94], large [5.9 +/- 0.2, n = 295] or giant breeds [6.1 +/- 0.5, n = 62] [P < 0.01]). Bitches older than 6 years had a lower whelping rate (68.2%) than younger ones (77.0%; P < 0.05). The duration of pregnancy was longer (P < 0.01) for bitches with a litter size of < 3 pups (61.7 +/- 0. 4 days, n = 30) than for bitches with larger litters (60.5 +/- 0.1 days, n = 177). These results show the potential of transcervical intrauterine insemination for routine artificial insemination in dogs. The results with frozen semen inseminations were optimised by inseminating bitches < or = 6 years old 2 and 3 days after ovulation with semen of good quality from males < or = 8 years old.
Ejaculates were collected form three mixed-breed male dogs daily for 3 d. The semen was diluted in either a nonfat dried milk solid-glucose (NFDMS-G) or egg yolk citrate (EYC) extender at a concentration of 25 x 10(6) sperm/ml. The diluted samples were exposed to three different storage temperatures (35, 22 and 4 degrees C). Three cooling rates (-1.0, -0.3 and -0.1 degrees C/min) were also investigated at the lowest storage temperature (4 degrees C). The semen was evaluated for total motility, progressive motility and velocity at 0, 6, 12, 24, 48, 72, 96 and 120 h after collection by two independent observers. Interactions between extenders, temperatures and time after collection were found for each of the variables. Nonfat dried milk solid-glucose diluent was superior to EYC (P<0.05) in preservating sperm motility parameters that were evaluated for most of the observations. The evaluated sperm motility parameters were also significantly superior (P<0.05) in semen stored at 4 degrees C than at 35 or 22 degrees C for most of the observations. The progressive motility and velocity of sperm in semen cooled at 4 degrees C in NFDMS-G were higher (P<0.05) at the fast and medium cooling rates (-1.0 and -0.3 degrees C) than at the slow cooling rate (-0.1 degrees C/min) at 24 and 72 h, and at 48 h, respectively. In conclusion, the present study suggests that canine spermatozoal motility is well preserved when a NFDMS-glucose extender is added to the semen and the semen is cooled at a medium or fast rate to a storage temperature of 4 degrees C. Additional studies are needed to evaluate the fertility of semen stored in this manner.
Four ejaculates were collected from each of 6 adult male beagle dogs. The second fraction was divided into 3 aliquants which were then diluted with physiological saline, an isoosmolar solution of sodium/meglumine diatroate, and an iso-osmolar solution of iohexol. The diluted samples were incubated at 39 degrees C and evaluated at 0, 60, 90, 120, 240 and 360 min after dilution. A variety of assessments was made, including, spermatozoal motility, spermatozoal morphology, and acrosorne status. The practicality of using 1.0 ml of iso-osmolar contrast medium combined with radiographic examination was evaluated as a method of confirming accurate placement of a transcervical uterine catheter by injecting contrast after positioning the catheter in 4 beagle bitches. The effect of the procedure on fertility was assessed using 5 greyhound bitches which were inseminated with fresh semen and in which pregnancy was monitored using diagnostic B-mode ultrasound imaging. There was no significant difference between physiological saline and the sodium/meglumine diatroate solution upon semen quality, while the iohexol solution produced a significant reduction in spermatozoal motility and morphology. No adverse clinical effects were observed when contrast medium was administered into the uterus to either group of bitches. A subjective assessment of radiographic quality showed that the sodium/meglumine diatroate solution, which contained twice the iodine concentration of the iohexol solution, produced significantly greater radiopacity and was radiographically more useful than the iohexol solution. The sodium/meglurnine diatroate solution had no adverse effect upon the fertility of dog semen, and all bitches that were inseminated with this technique conceived and maintained the pregnancy to term. Litter size was considered to be normal for the breed. Small volumes of an iso-osmolar solution of sodium/meglumine diatroate may be useful for ensuring correct placement of transcervical catheters prior to artificial insemination in the bitch.
Semen preservation and artificial insemination (AI) in the canine has become a common practice in veterinary medicine. Chilled dog semen is easy to handle, and several extenders can be used. The aim of this study was to compare the effects on canine spermatozoa of seminal plasma and 3 extenders commonly used for chilled semen preservation in clinical practice. The characteristics evaluated were sperm motility; velocity; plasma membrane status (assessed with a fluorescence staining technique and hypo-osmotic swelling test); acrosome morphology; semen pH; and semen osmolarity. These criteria were monitored daily in the ejaculates of 11 dogs. The ejaculates were divided into 4 aliquots. Each aliquot was extended in autologous seminal plasma, egg-yolk Tris, egg-yolk milk or egg-yolk cream and preserved at 4 degrees C for 4 d. In 10 of 11 semen samples extended in autologous seminal plasma, motility had already decreased to 0% by Day 2, and the percentage of spermatozoa with intact membranes was lower than in the 3 extenders (P < 0.05). Motility up to Day 4 was higher in egg-yolk Tris-stored spermatozoa (53.6%) than in those preserved in egg-yolk milk (30.4%) and egg-yolk cream (14.1%). Spermatozoa stored in egg-yolk Tris also had the highest sperm velocity, whereas no difference was found in plasma membrane or acrosome status (P>0.05). Egg-yolk Tris extender seems to be superior to the other extenders tested, to preserve dog semen at 4 degrees C, although differences were not significant for all the parameters.
A technique for laparoscopic intrauterine insemination in bitches is described. During natural estrus, 5 beagle bitches were inseminated and S others were naturally mated (control group) twice at a 48-h interval on Days 3 and S (n = 4) or Days 4 and 6 (n = 6) after the increase in plasma progesterone considered to be indicative of the day of the preovulatory LH peak. All the inseminations were with fresh semen and under general anesthesia. The technique involved the introductions of 1) a Verres needle to insufflate the abdominal cavity by direct punction on the middle line 1 cm over the umbilicus, 2) a laparoscope to visualize the abdominal cavity by a 1 cm puncture on the middle line 1 cm under the umbilicus, 3) a forceps used to manipulate the uterus by a 0.5 cm puncture at 2 to 3 cm lateral to the mammary glands, and 4) an 18-g catheter used to puncture the uterus on the middle line between the 3rd and 5th mammary gland. The uterine body was grasped by the forceps and elevated against the ventral abdominal wall. The 18-g catheter was then inserted through the abdominal wall directly into the uterine lumen, and 1.0 ml of fresh semen containing 250 to 480 x 10(6) spermatozoa/ml was injected. The inseminations resulted in pregnancies in all animals. Litter size was similar in the artificially inseminated and naturally mated bitches (5 +/- 1.8 and 4.8 +/- 1.6 pups per litter, respectively). Bitches in the artificially inseminated group delivered at 65.2 +/- 0.8 d and in the natural mated group at 65.4 +/- 0.5 d after the LH peak. In conclusion, this paper gives the first results of intrauterine laparoscopic insemination in bitches, indicating interesting perspectives for this technique in dog's reproduction.
A method for concentrating canine semen prior to freezing was developed. Concentration was by centrifugation at 1470 g at room temperature, after which the majority of seminal fluid was removed. Motility, speed of progression, and morphology of sperm were not affected by concentration. Subsequent artificial insemination using concentrated semen resulted in a conception rate of 92%. The offspring were normal and healthy. The mean litter size (6.7) and birth weight (256.3 g) were comparable to those reported by a commercial supplier (6.2 and 255.7 g) of the same breed (beagle).
In diesem Versuch sind 11 Hündinnen mit tiefgefrorenem Sperma besamt worden.
Die spermienreiche Ejakulatsfraktion wurde unmittelbar nach der Samenentnahme mit einer Tris-Fructose-Zitronensüure-Lösung, die 8 Vol. % Glyzerin und 20 Vol. % Eidotter enthielt, etwa 1: 4 verdünnt. Wührend einer 3stündigen Equilibrierungszeit wurde der Samen auf + 5 °C heruntergekühlt, and in PVC-Röhrchen im Stickstoffdampf eingefroren.
Die Inseminationsdosen, die ungefähr 150 × 106 Spermien enthielten und 3 Wochen bis 1 1/2 Jahre gelagert waren, wurden unmittelbar nach dem Auftauen für 6,5 Sek. im Wasserbad von + 75 °C, durch den Cervicalkanal intrauterin deponiert. Es wurde meistens zweimal mit etwa 48stündigen Intervallen inseminiert. Von den 11 Hündinnen konzipierten 10 und brachten von ein bis sieben Junge. Die höchste Zahl der lebendigen Welpen in einem Wurf war sechs.
Insemination with frozen dog semen was performed in a small trial including 11 bitches. The semen was diluted about 1: 4 with Tris-fructose-citric acid extender containing 8 % (v/v) glycerol and 20 % (v/v) egg yolk, equilibrated for 3 hrs and frozen in P.V.C.-straws by use of N2-vapour. The insemination doses being stored in liquid N2 from 3 weeks to 1 1/2 year and containing about 150 × 106 spermätozoa, was deposited in the uterus via the cervical canal immediately after thawing at 75 °C for 6,5 sec. By this procedure conception was obtained in 10 of the 11 bitches. The litter size ranged from one to seven puppies, the highest number of living puppies being six.
In this paper the exfoliated cell types present in canine vaginal smears have been classified using a procedure based on that described by Schutte, (1967a). Nine beagle bitches were studied and the proportion of anuclear, superficial, large intermediate, small intermediate and parabasal cells was evaluated in a total of 155 vaginal smears obtained during each stage of the oestrous cycle. The main change in proestrus and oestrus was a rise in the proportion of anuclear and superficial cells associated with a decrease in large and small intermediates and parabasals. A rise in the proportion of small intermediates occurred at the beginning of metoestrus.
Reproduction in the Dog
- A E Harrop
Die künstliche Besamung von Hündinnen mit defizienter Fruchtbarkeit. (The artificial insemination of bitches with low fertility.)
- Knaus E.
Kunstig sædoverføring på hund. (Artificial insemination in the dog.)
- Andersen K.