Insemination Of Rabbits Research Articles

Potential use of dimethyl sulfoxide (DMSO) in artificial insemination of rabbits

The aim of this work was to analyse the effect of incubation dimethyl sulfoxide (DMSO) with insemination dose (ID) on reproduction parameters (kindling rate, number of live and still-born kits and birth weight of kits). The experiments were carried out under the conditions of two rabbit breeds. An ejaculate was diluted to concentration of 40 to 50 million/0.5 ml/ID. DMSO was added to the ID in concentration of 0.5 M DMSO. Control ID did not contain any DMSO. Kindling rates obtained from 2 different breeds (P1, P2) showed minor improvement (+4.36% P1; +4.06% P2) between the monitored groups of females, however without statistically significant differences. Number of live born kits in litter obtained from breeds P1 and P2 showed minor improvement (+0.61 pcs P1; +0.13 pcs P2) compared to the control groups (p>0.05). The weight of live born kits was higher in experimental groups (+3.85 g P1 = p≤0.001; +1.18 g P2 = p>0.05) compared to the control groups. Monitoring of sperm quality indicators (1, 3 and 6 hours incubation) in vitro conditions (CASA – Computer Assisted Semen Analyzer) showed the best results in the control group of non-affected DMSO. The data obtained from our experiments suggest the possitive effects of DMSO incubation on reproduction parameters especially in vivo.

Trends in rabbit insemination extenders for fresh and frozen semen. A review

Artificial insemination (AI) has become a popular technique in rabbit farms worldwide. This report discusses the progress made on semen extenders used in rabbit AI, setting out the latest innovations. Fresh and frozen semen have different requirements, so the extender composition will vary depending on the type of semen used. We discuss the endocrine supplementation of extenders for ovulation induction, the use of active molecules as an alternative to conventional antibiotics and the extenders developed for rabbit sperm cryopreservation.

123 Induction of ovulation after artificial insemination in rabbits: intramuscular injection of gonadotrophin-releasing hormone analogue versus intravenous administration of mated doe serum.

Reproduction, Fertility and Development is an international journal publishing original research , review and comment in the fields of reproduction and developmental biology in humans, domestic animals and wildlife

Induction of ovulation after artificial insemination in rabbits: Intramuscular injection of gonadotropin-releasing hormone (GnRH) agonist vs. intravenous administration of mated doe serum

BACKGROUND: Rabbits are reflex ovulators with the ovulatory process triggered by neuro-hormonal impulses generated during natural mating. When applying artificial insemination (AI), an array of biostimulation techniques and/or exogenous hormones (e.g., gonadotropin-releasing hormone (GnRH) or its analogues) must be used to induce ovulations in female rabbits. However, the effectiveness of various biostimulation techniques and exogenous hormones is not always satisfactory and the use of GnRH analogues is additionally associated with high production costs. Therefore, developing an alternative inexpensive, efficient and safe treatment for the induction of ovulation in artificially inseminated does is urgently needed. OBJECTIVES: In the present study, we examined and compared the effects of mated doe serum (MDS) and GnRH analogue (Gonadorelin) administered immediately after artificial insemination on circulating concentrations of luteinizing hormone (LH) and fertility in New Zealand does. METHODS: Forty artificially inseminated does were allocated to four equinumerous groups that received: 0.2 ml of saline i.m. (Control G), 0.8 µg of Gonadorelin dissolved in 0.2 ml of saline i.m. (Treatment G), 2.5 ml of mixed sex normal rabbit serum i.v. (Control M) or 2.5 ml of mated doe serum (MDS)/doe i.v. (Treatment M). RESULTS: A peak in systemic LH concentrations occurred earlier in Treatment M compared with Treatment G does (71 vs. 107 min post-AI, respectively; P≤ 0.05); mean LH concentrations did not vary (P≤ 0.05) from the pre-AI values in both control groups. Serum LH concentrations remained higher (P≤ 0.05) in Treatment M compared with Treatment G does from 30 to 90 min post-AI but they were greater (P≤ 0.05) in Treatment G than in Treatment M group at 120 and 160 min after AI. Gonadorelin and MDS injections both resulted in the same kindling rate (80%) at each of the four consecutive AI’s (initiated 30 days post-partum) and they were significantly greater than those recorded in control animals (20%). CONCLUSION: It can be concluded that MDS administration is an effective treatment to induce ovulations in rabbits, with the repeatability like that achieved with a GnRH analogue.

Artificial insemination of rabbits: current state and practical possibilities of the method

Relevance. Rabbits have great reproductive and productive potential. In the industrial (conveyor) system of rabbit production, the brood stock of the rabbit farm is divided into production groups and artificially inseminated on a strictly fixed day of the week on the 4th or (more often) 11th day of lactation. Only clinically healthy and well-fed females are allowed to insemination. It is shown that with an intensive rate of reproduction of the herd from one rabbit, it is possible to receive from 40...55 to 60...65 weaned rabbits and produce up to 120 kg of rabbit meat annually. Methods. The technological processes and practical possibilities of the method of artificial insemination of rabbits are considered and analyzed. Results . Work on artificial insemination of rabbits is carried out in the following order: collecting semen from the bucks, assessing the quality of ejaculate, diluting and short-term storing sperm in vitro, stimulating sexual activity and diagnosing the sexual receptivity of suckling female rabbits, intravaginal insemination of does with hormonal induction of ovulation. Sperm from male rabbits is obtained on a receptive female with the help of an artificial vagina: two ejaculates collected once a week with an interval of at least 15 min. The process of collecting semen on an artificial vagina takes average 26.2 seconds. After macro-and microscopic evaluation, the ejaculate is diluted 1:5...1:10 with a medium based on Tris-or Hepes-buffer. For dilution and short-term storage of sperm directly in the farm environment (up to 24...48 hours), ready-to-use commercial extenders are also used (for example, Lepus®, Cortalap®, Merk III®, Formula® etc.). The selection of rabbits for insemination is carried out according to the signs of estrus and sexual reaction of the female to the male. 48 hours before the planned insemination, all suckling rabbits of the production group are injected with the gonadotropic drug folligon (at a dose of 20 IU). Exogenous gonadotropic stimulation induces cyclic growth of follicles, synchronizes the manifestation of sexual activity in rabbits of the production group, improves reproductive efficiency of rabbit does in term of fecundity (fertility and prolificacy). The technique of artificial insemination of rabbits is quite simple. Using a semi-automatic syringe with a removable disposable sterile catheter, sperm is inserted deeply into the rabbit vagina in a volume of 0.5 ml. With an effective organization of work, an insemination technician and an assistant can inseminate up to 150 female rabbits in 1 hour (with simultaneous hormonal induction of ovulation).Good results, almost as with natural insemination, are obtained when using freshly obtained diluted or diluted chilled sperm for insemination with a shelf life of up to 6 ... 12 hours.

Artificial insemination in rabbits: factors that interfere in assessing its results

Artificial insemination in rabbits: factors that interfere in assessing its results

Protection of GnRH analogue by chitosan-dextran sulfate nanoparticles for intravaginal application in rabbit artificial insemination

The present study was designed to prove new rabbit insemination extenders containing aminopeptidase inhibitors (AMIs) with or without chitosan (CS)-dextran sulfate (DS) nanoparticles entrapping the GnRH analogue. In addition, different hormone concentrations were tested in these extenders, evaluating their in vivo effect on rabbit reproductive performance after artificial insemination. A total of 911 females were inseminated with semen diluted with the four experimental extenders (C4 group: 4 μg buserelin/doe in control medium (Tris-citric acid-glucose supplemented with bestatin 10 μM and EDTA 20 mM), C5 group: 5 μg of buserelin/doe in control medium, Q4 group: 4 μg of buserelin/doe into CS-DS nanoparticles in control medium, Q5 group: 5 μg of busereline/doe into CS-DS nanoparticles in control medium). Results showed that fertility was significantly lower in C4 group compared to C5, Q5 and Q4 groups (0.7 versus 0.85, 0.85 and 0.82, respectively). On the contrary, prolificacy was similar in the four experimental groups studied (P > 0.05). We conclude that the CS-DS nanoparticles prepared by a coacervation process as carrier for buserelin acetate allows reducing the concentration of hormone used in extenders supplemented with bestatin and EDTA without affecting the fertility and prolificacy of rabbit females.

Chitosan-dextran sulphate nanoparticles for GnRH release in rabbit insemination extenders.

This study was designed to develop chitosan (CS)-dextran sulphate (DS) nanoparticles containing a GnRH analogue and to study their effect on rabbit (Oryctolagus cuniculus) semen quality. Six experimental extenders were tested as follows: (control) Tris-citric acid-glucose (TCG), (1) 0.05% CS-0.05% DS (4:1), (2) 0.1% CS-0.05% DS (4:1), (3) 0.05% CS-0.05% DS (3:1), (4) 0.1% CS-0.05% DS (3:1), (5) 0.1% CS-0.05% DS (2:1). CS and DS were dissolved in TCG medium, and nanoparticles were obtained through magnetic stirring. Rabbit seminal samples were incubated up to 5hr at 37°C in the extenders, and seminal quality was evaluated. The entrapment efficiency was 40%-50%. After 5hr at 37°C, a 20% of the hormone was released. Results showed that the presence of CS-DS nanoparticles did not affect rabbit semen motility, viability and membrane functionality; however, acrosome integrity was significantly higher versus control (p<.001).

Evaluation of effectiveness of an innovative semen extender (Formula®) comparing with a traditional extender (Lepus®) for artificial insemination in rabbits does

This study aimed to investigate the preservability and viability of the rabbit spermatozoa diluted in a new semen extender Formula® in comparison with Lepus® at 17 °C of storage. The main characteristic of the new extender formulation is the use of an enzymatic agent associated to a polysaccharide as energy source precursor, added with gentamycin. During eight trials, ejaculates from 70 bucks were collected and diluted at 1:10 ratio with both the extenders, after 24 h of storage the semen doses were used for the artificial insemination (AI). Aliquots of the semen doses for each trial were stored at 17 °C, the total and progressive motility were checked at 0, 4, 12, 18, 24, 36, 48, 60, 72, 84, 96, 108 h of storage. A total of 1267 and 1525 does were inseminated, respectively with Formula® and Lepus®. During storage the mean total and progressive motility (77.23% and 72.854%, respectively) were significantly higher for Formula® (p < .01) and the progressive motility at almost 70% was maintained for at least 60 h vs the 24 h of storage for Lepus® with significant differences after 12 h of storage (p < .05). The new extender reported a higher pregnancy rate (p < .05) and an average of 9.25 rabbits born per litter vs 8.83 for the traditional extender (p < .05), while the mean of the newborn alive was 9.08 using Formula® vs 8.51 with Lepus® (p < .05). In conclusion, the use of Formula® is recommended for rabbit semen AI programmes.

Improve intra-uterine insemination in rabbits using ultra-high temperature skim milk as extender to keep semen at room temperature

Two experiments were carried out to examine invitro quality and invivo fertility of rabbit semen diluted in ultra-high temperature (UHT) skim milk. In the first experiment, pooled ejaculates of 10 adult rabbits were divided in three aliquots. Each aliquot was diluted in saline solution, TrisC or UHTm extender and kept at room temperature for 24h. Sperm quality assessment was performed during all the incubation periods. In the second experiment, 27 adult rabbit does were inseminated with semen incubated for 5h. Embryo recovery was performed 96h after insemination. Results showed that treatments diluted in UHTm registered the highest values of spermatozoon with total motility, intact and functional plasma membrane and greater number of embryos recovered in rabbit does. We conclude that UHT skim milk would be a good extender for improved intra-uterine insemination in rabbits and to keep sperm cells for several hours at room temperature.

Induction of ovulation in rabbits by adding Lecirelin to the seminal dose: In vitro and in vivo effects of different excipients

This study evaluates the effect of Lecirelin (Dalmarelin®, Fatro, Italy) diluted in different excipients (benzilic alcohol, benzoic acid and paraben) added to a seminal dose on LH concentrations, progesterone concentrations and ovarian status in rabbits. The in vitro effect on spermatozoa was also tested. A total of 100 multiparous female rabbits were divided into 5 groups, which at the moment of AI, received 0.2mL (5μg/dose) intramuscular (im) inoculation of Lecirelin (control) or the same Lecirelin dose administered intravaginally (iv) with the seminal dose alone (Lecirelin group) or with benzilic alcohol (Lecirelin BA group), benzoic acid (Lecirelin BAc group) or parabens (Lecirelin PA group) as an excipient. After 7 days, 10 rabbits per group were euthanized to analyze their ovarian status. In the control group, a high LH peak was detected 30min post AI, while in the iv groups a slight increase in LH occurred after 120min. The ovulation and fertility rate was similar in control and Lecirelin groups, while the lowest fertility rate was detected in the Lecirelin BA group. In a second experiment, the semen samples collected from male rabbits were diluted in TALP (control) or mixed with the 5μg of Lecirelin solutions used in the first experiment. The highest percentage of capacitated sperm (68.3%) was recorded in the Lecirelin PA. The lowest percentages were observed in the Lecirelin BA and BAc groups. In conclusion, the iv administration of Lecirelin represents an alternative method for simplifying rabbit insemination procedures.

Development of a Sperm Preparation Method for Artificial Insemination in Rabbits

Development of a Sperm Preparation Method for Artificial Insemination in Rabbits

Elimination of Apoptotic Spermatozoa from Rabbit Insemination Dose Using Annexin V Associated with the MACS Technique. A Preliminary Study

The aim of this study was to verify whether the separation and elimination of the apoptotic fraction in rabbit semen using a MACS technique may improve sperm fertility potential and consequently rabbit kindling rate. Semen samples from 25 New Zealand White (NZW) rabbit males were collected using an artificial vagina and evaluated using the CASA system for concentration and motility. For artificial insemination the best 11 bucks were chosen based on motility parameters. Their ejaculates were mixed to make a heterospermic pool and routinely diluted in a commercial insemination diluent (MiniTüb, Tiefenbach, Germany) at a ratio of 1:6. Diluted heterospermic spermatozoa were filtered through a Sartorius filter to wash out seminal plasma, re-diluted in binding buffer (Annexin V Microbead Kit, Miltenyi Biotec, Germany) at a ratio of 1:3.66 and divided into two groups: an experimental group intended for MACS separation and control group without MACS separation. Then hormonally treated females of NZW rabbits were inseminated with fresh doses of filtered heterospermic semen (n = 27; 0.5 ml I.D. per female) and MACS separated semen (n=28; 0.5 ml I.D. per female). Separation and subsequent elimination of apoptotic spermatozoa (positive selection) from the insemination dose (after negative MACS selection) was verified under in vivo conditions on the basis of increased kindling rate in the experimental group in comparison with kindling rate in the control group (81.3% vs. 73.8%). In conclusion, elimination of apoptotic spermatozoa by the use of the MACS technique results in a slight improvement in kindling rate of rabbit does.

Technical Note: Artificial insemination in rabbits: laboratory and field trial with three different semen extenders.

Today a great deal of research is focused on the development of new extenders that allow the refrigeration and maintenance of rabbit semen for a longer period of time. In this study, semen diluted with 3 different extenders (A, B, and C) and stored at two different temperatures (4°C and 38°C) were evaluated using both laboratory and in vivo tests. The best results were obtained with extender C (INRA 96) which, in the first 10 h of the test at 4°C, displayed about 80% higher motility compared to the other two extenders and preserved optimal seminal fluid motility for over 34 h after dilution. In the test at 38 °C, the motility of semen diluted with extender C was 52% in the fifth h vs 21% of the semens diluted with extenders A (Lepus) and B (Verdunnungsmischung). Another test involved artificial insemination (AI) of 1800 lactating does using refrigerated semen diluited with the extenders under study. The fertility rate and litter size obtained with semen diluted with extender C was higher (78.1% and 8.65, respectively) than those obtained with extenders A (71.2% and 8.15, respectively) and B (71.05% and 8.13, respectively) in both parallel and sequential tests. In conclusion, extender C offers greater vitality and motility to rabbit spermatozoa, thus higher fertility rates to rabbits does.

Artificial Insemination in Rabbits

INTRODUCTIONArtificial insemination (AI) is used in rabbit husbandry to improve breeding management. Conception rates after AI with fresh semen are equivalent to or even better than those obtained by natural mating. Also, AI has the advantage of avoiding contact between animals. Furthermore, AI with frozen sperm is particularly useful for assisted reproduction and conservation of rabbit genetic resources, and in some cases, frozen semen produce results similar to those obtained in AI using fresh sperm. This protocol describes the most commonly used protocol for AI using fresh sperm.

Ovulation induced by mucosa vaginal absorption of buserelin and triptorelin in rabbit

The aim of this study was to evaluate the supplementation of semen extender with two synthetic GnRH analogues (buserelin and triptorelin) to induce ovulation in rabbit does submitted to artificial insemination. In a first experiment, 255 receptive multiparous does were inseminated with 0.5 mL of Tris–citrate–glucose extender supplemented or not with two GnRH synthetic analogues. Experimental groups were: NC (not supplemented extender), PC (not supplemented extender and does treated with 1 μg of buserelin i.m.), B2 (2 μg per female buserelin supplemented extender), B5 (5 μg per female buserelin supplemented extender), T2 (2 μg per female triptorelin supplemented extender) and T5 (5 μg per female triptorelin supplemented extender). Thirteen does of NC females ovulated, reaching an ovulation rate similar to the other groups. Ovulation rate was similar in all groups (11.4–12.5). The efficiency of ovulation induction was very low (32.5%) in NC group and showed the higher results in PC females (97.8%). Only B5 females reached similar ovulation induction response than PC group. In a second experiment, 702 receptive does were inseminated to compare fertility and prolificacy parameters from the conventional insemination technique (control group, females treated with 1 μg per female of buserelin intramuscularly) versus a supplementation with buserelin or triptorelin (5 μg per female) in semen extender (B5 and T5 groups, respectively). Fertility and prolificacy parameters were similar among the groups (77.8% fertility rate, 73.9% kindling rate, 9.4 live born and 9.9 total born). This study demonstrate the possibility of ovulation induction in rabbits by adding two GnRH synthetic analogues in the seminal doses and open up new prospects for changing rabbit insemination procedures.

Rabbit reproductive performance after insemination with buserelin acetate extender

Rabbit farmers and insemination centres have established new requirements relating to males (genetic, nutritional and environmental factors) and rabbit insemination techniques. The aim of this study was to evaluate buserelin acetate on the reproductive performance of nulliparous, multiparous lactating and multiparous non-lactating does inseminated on three commercial farms. Two thousand two hundred and three commercial crossbred does belonging to three commercial farms were inseminated with pooled semen from males of two selected meat lines; R line (UPV rabbit selection centres, Spain) in farms 1 and 2, and PS Hyplus 59 line (Grimaud Frère, France) on farm 3. Ejaculates from 12–20 males from each line were pooled and diluted to twelve million sperm per millilitre by adding TRIS–citrate-extender. Diluted semen from each male line was split into two fractions, the first without buserelin acetate added to semen (Control group) and the second fraction was supplemented with 10 μg of buserelin acetate per millilitre (Buserelin group). Receptive females (red colour of vulvar lips) were inseminated with 0.5 mL using a standard plastic curved pipette. Artificial insemination with semen extended with buserelin resulted in lower pregnancy and kindling rates irrespective of the physiological status of females or the farm (78.7% and 76.0% vs 85.8% and 83.4%, buserelin extender group and control respectively, P<0.01), although does from both treatment groups had a similar litter sizes (10.4 and 9.6 total and alive born, respectively). This study opened up new prospects for changing rabbit insemination procedures.

From experiments with artificial insemination of rabbits to assisted reproductive technologies

The contribution of the Ott institute collaborators in formation and development of auxiliary reproduction technologies is elucidated in this article.

Pregnancy by tubal insemination in rabbits using sperm cells capacitated in vitro.

It has been suggested that the mechanical interference involved in inserting a tube into the oviduct before ovulation, during tubal insemination, may impair the capacity of the tubal fimbriae to pick up ovulated eggs. When fresh sperm cells are used, the semen has to be injected into the oviduct before ovulation to allow time for sperm capacitation. In the present study in rabbits, sperm cells capacitated by pre-incubation in vitro were injected into the oviducts through the tubal fimbriae after ovulation. Two of the six rabbits inseminated became pregnant and gave birth to one and three offspring, respectively. Injecting capacitated sperm cells after ovulation may avoid the potential problems posed by mechanical damage of the tubal fimbriae.

Relation between the number of sperms to be deposited and pregnancy rate in tubal insemination in rabbits.

Pregnancy rate of tubal insemination with semen diluted to concentrations of x10(0) to x10(7) was studied in rabbits. The animals were laparotomized under general anesthesia, and 0.05 ml of diluted semen was injected with a glass capillary from the tubal fimbria into the oviduct. The semen was obtained from mature male rabbits by means of an artificial vagina and diluted to concentrations between x10(0) and x10(7). One hour after the insemination, ovulation was induced by administration of hCG. Six experimental groups were set up according to the semen concentrations. In the x10(0), x10(2), x10(4), and x10(7) groups, newborn rabbits were obtained. The best pregnancy rate was obtained with the x10(2) groups, in which 10(5) level of sperms were deposited. The newborn rabbits were normal not only morphologically, functionally, but also in chromosomal examination. The results suggested that tubal insemination with a small number of sperms could be applied in sterility due to oligospermia in human.