198 EXOGENOUS CONTROL OF FOLLICULAR WAVE EMERGENCE IN WOOD BISON (BISON BISON ATHABASCAE)

2010 ◽  
Vol 22 (1) ◽  
pp. 257 ◽  
Author(s):  
R. B. McCorkell ◽  
W. Paziuk ◽  
L. Smart ◽  
M. R. Woodbury ◽  
G. P. Adams
Keyword(s):  
Ovarian Function ◽  
Follicular Development ◽  
Reproductive Technologies ◽  
Bison Bison ◽  
Control Group ◽  
New Wave ◽  
Handling Stress ◽  
Follicular Wave ◽  
End Point ◽  
Wood Bison

Two methods for synchronizing ovarian follicular development in both wood bison (Bison bison athabascae) and plains bison (Bison bison bison) were tested as part of a project to conserve wood bison through the application of advanced reproductive technologies. A secondary objective was to test the effect of a long-acting neurolept tranquilizer, pipothiazine palmitate, on ovarian function in bison. Female wood bison (4 years old; n = 14) and plains bison (2-8 years old, n = 10), previously conditioned to daily examination in a chute, were divided randomly into 3 groups in which 1) ovarian follicles ≥5 mm were ablated by ultrasound-guided transvaginal follicle aspiration, 2) 5 mg of estradiol-17β in canola oil was given i.m. or 3) no treatment was given (control). The experiment was conducted in 3 replicates so that each animal rotated through each of the groups. Half of the bison, blocked by subspecies and treatment group, were given a single dose (150 mg) of pipothiazine palmitate i.m. The ovaries were examined daily by transrectal ultrasonography beginning 4 days before treatment and continuing until the dominant follicle of a new wave reached a diameter of 10 mm. No effect of treatment with pipothiazine palmitate was detected for any end point. In addition, no differences were detected between wood and plains bison for any end point. Consequently the pipothiazine palmitate and subspecies treatment groups were collapsed for further analyses. The interval and variation in the interval to new follicular wave emergence were compared by ANOVA. Wave emergence was detected on Day 1.0 ± 0.2 (mean ± SEM; Day 0 = day of treatment) in the follicle ablation group, and was earlier (P < 0.05) than in both the estradiol (Day 3.3 ± 0.3) and control (Day 4.0 ± 0.4) groups. The interval to follicle wave emergence was least variable in the follicle ablation group (P < 0.05) and tended to be less variable in the estradiol group (P = 0.09) than in the control group (residuals, 0.1 ± 0.04, 1.0 ± 0.2, and 1.6 ± 0.3 days, respectively). Ovulations occurred subsequent to estradiol administration in 10 of 23 (43%) bison. In conclusion, ovarian follicular wave emergence can be synchronized in bison during the anovulatory season. Follicular ablation consistently shortened and decreased the variability in the interval to new wave emergence. The synchronizing effect of estradiol was confounded by the induction of ovulation. Progesterone will be added in future studies to control the ovulatory effect of estradiol. Pipothiazine palmitate had no discernable effect on ovarian function and maybe useful in reducing the effects of handling stress on untrained animals. Supported by a grants from the Advancing Canadian Agriculture and Agri-Food Fund, the Agri-Food Innovation Fund, Parks Canada, the World Wildlife Fund, and the Northwest Territories.

Ovarian synchronisation in wood bison (Bison bison athabascae) during the anovulatory season

2014 ◽  
Vol 26 (4) ◽  
pp. 521 ◽  
Author(s):  
J. Manuel Palomino ◽  
Robert B. McCorkell ◽  
Murray R. Woodbury ◽  
Gregg P. Adams
Keyword(s):  
Untreated Control ◽  
Transvaginal Ultrasound ◽  
Hormone Treatment ◽  
Bison Bison ◽  
New Wave ◽  
Control Phase ◽  
Treatment Groups ◽  
Follicular Wave ◽  
Wood Bison ◽  
Experimental Treatments

Two experiments were performed in wood bison during the anovulatory season to establish an effective protocol for ovarian synchronisation. In an untreated control phase, bison cows (n = 19) were examined daily to establish the interval to new follicular wave emergence (4.9 ± 0.7 days) for the purposes of comparison with the experimental treatments. In Experiment 1, bison were treated by transvaginal ultrasound-guided follicular ablation (n = 9) or with 2 mg, i.m., 17β-oestradiol (n = 10). In Experiment 2, bison were treated by follicular ablation (n = 9) or with 2 mg, i.m., 17β-oestradiol +100 mg, i.m., progesterone (n = 10). In Experiment 1, the interval to new wave emergence for control, follicular ablation and 17β-oestradiol-treated groups was 4.9 ± 0.7, 1.1 ± 0.1 and 3.1 ± 0.4 days, respectively (P < 0.05). The degree of synchrony was 2.4 ± 0.4, 0.2 ± 0.1 and 0.8 ± 0.2 days, respectively (P < 0.05). In Experiment 2, the interval to new wave emergence for control, follicular ablation and 17β-oestradiol + progesterone-treated groups was 4.9 ± 0.7, 1.2 ± 0.2 and 3.3 ± 0.3 days, respectively (P < 0.05), and the degree of synchrony was 2.4 ± 0.4, 0.2 ± 0.1, and 0.8 ± 0.2 days, respectively (P < 0.05). The degree of synchrony did not differ between ablation and hormone treatment groups in either experiment, but was greater in treatment groups than in the untreated control phase. Both follicular ablation and hormone treatment shortened and decreased the variability in the interval to follicular wave emergence in bison, but wave emergence occurred earlier after follicular ablation.

415 INDUCTION OF FOLLICULAR WAVE EMERGENCE IN WOOD BISON BY FOLLICULAR ABLATION OR TREATMENT WITH ESTRADIOL AND PROGESTERONE

2010 ◽  
Vol 22 (1) ◽  
pp. 364 ◽  
Author(s):  
J. M. Palomino ◽  
R. B. McCorkell ◽  
B. Balog ◽  
D. Ambati ◽  
M. Woodbury ◽  
...  
Keyword(s):  
Transvaginal Ultrasound ◽  
Initial Study ◽  
Bison Bison ◽  
New Wave ◽  
Control Phase ◽  
Follicular Wave ◽  
Innovation Fund ◽  
Specific Objective ◽  
Wood Bison ◽  
Parks Canada

Reclamation of Canada’s threatened wood bison (Bison bison athabascae) herd is complicated by endemic disease. As part of an overall goal to conserve bison genetics, the specific objective of this study was to develop a protocol to control follicular wave emergence in bison for the purposes of ovarian superstimulation and collection of disease-free oocytes. In an initial study, the synchronizing effect of follicular ablation and estradiol (E2) treatment was examined. Ablation was effective, but the effects of E2 (5 mg) were confounded by treatment-induced ovulation in some animals. Two experiments were done to determine the effect of a reduced dose of E2 or the addition of progesterone (P4) in comparison with follicular ablation. Bison cows (n = 19), ≥3 years old, were scanned for 14 days to determine the mean and variance in the interval to follicular wave emergence (control phase). In Experiment 1, bison were assigned randomly to 2 groups: follicular ablation (n = 9) or 2 mg of E2i.m. (n = 10). In Experiment 2, the same bison were randomly assigned to 2 groups: follicular ablation (n = 9) or 2 mg of E2+ 100 mg of P4 i.m. (n = 10). Ablation involved transvaginal ultrasound-guided aspiration of all follicles ≥5 mm. Wave emergence was determined retrospectively by identification of the follicle destined to become dominant at an initial diameter of 4 to 5 mm, with a concurrent increase in the number of follicles ≥4 mm. The interval and variation in the interval to emergence of a new follicular wave was compared among the control phase and treatment groups by ANOVA. In Experiment 1, the interval to new wave emergence (mean ± SEM) was 4.9 ± 0.66, 1.1 ± 0.11, and 2.4 ± 0.47 days from the start of the control phase, follicular ablation, and E2 treatment, respectively (P < 0.001). The degree of synchrony (residuals) was 2.4 ± 0.36, 0.2 ± 0.09, and 1.2 ± 0.24 days for the control phase, follicular ablation, and E2 treatment, respectively (P < 0.001). Ovulation was detected in 1 bison treated with E2. In Experiment 2, the interval to new wave emergence (mean ± SEM) was 4.9 ± 0.66, 1.2 ± 0.15, and 2.9 ± 0.31 days from the start of the control phase, follicular ablation, and E2 + P4 treatment, respectively (P < 0.001). The degree of synchrony was 2.4 ± 0.36, 0.2 ± 0.08, and 0.7 ± 0.20 days for the control phase, follicular ablation, and E2 + P4 treatment, respectively (P < 0.001), and no ovulations were detected. In conclusion, follicular ablation, E2, and E2 + P4 treatments all shortened and decreased the variability in the interval to new wave emergence in bison, but follicular ablation consistently produced a quicker and more synchronous response. Supported by grants from the Advancing Canadian Agriculture and Agri-Food Fund (ACAAF), the Agri-Food Innovation Fund, Parks Canada, the World Wildlife Fund, and the Northwest Territories.

Progesterone as the driving regulatory force behind serum FSH concentrations and antral follicular development in cycling ewes

2011 ◽  
Vol 23 (2) ◽  
pp. 303 ◽  
Author(s):  
Tanya E. Baby ◽  
Pawel M. Bartlewski
Keyword(s):  
Luteal Phase ◽  
Follicular Development ◽  
Treated Group ◽  
Time Frame ◽  
Oestrous Cycle ◽  
Control Group ◽  
Corpora Lutea ◽  
Follicular Waves ◽  
Follicular Wave ◽  
And Control

Ovarian antral follicles in sheep grow in an orderly succession, producing typically three to four follicular waves per 17-day oestrous cycle. Each wave is preceded by a transient increase in circulating FSH concentrations. The mechanism controlling the number of recurrent FSH peaks and emerging follicular waves remains unknown. During the ewe’s oestrous cycle, the time between the first two FSH peaks and days of wave emergence is longer than the intervals separating the ensuing FSH peaks and follicular waves. The prolonged interpeak and interwave interval occurs early in the luteal phase when low levels of progesterone are secreted by developing, or not fully functional, corpora lutea (CL). The purpose of the present study was to determine the effect of varying progesterone (P4) levels on circulating concentrations of FSH and antral follicular development in sheep. Exogenous P4 (15 mg per ewe, i.m.) was administered twice daily to six cycling Rideau Arcott × Dorset ewes from Day 0 (ovulation) to Day 4 (the mean duration of the interwave interval); six animals served as controls. Follicular growth was monitored in all animals by daily transrectal ultrasonography (Days 0–9). Jugular blood samples were drawn twice a day from Day 0 to Day 4 and then daily until Day 9 to measure systemic concentrations of P4, FSH and 17β-oestradiol (E2). The first FSH peak after ovulation was detected on Days 1.5 ± 0.2 and 4.2 ± 0.2 in treated and control ewes, respectively (P < 0.05). The next FSH peak(s) occurred on Day 3.9 ± 0.3 in the treated group and on Day 6.4 ± 0.5 in the control group. Consequently, the treated group had, on average, three follicular waves emerging on Days 0, 3 and 6, whereas the control group had two waves emerging on Days 0 and 5. Mean serum E2 concentrations were greater (P < 0.05) in control compared with treated ewes on Days 1.3, 2.3, 3.3, 4.0 and 4.3 after ovulation. In summary, creation of mid-luteal phase levels of P4 in metoestrus shortened the time to the first post-ovulatory FSH peak in ewes, resulting in the emergence of one more follicular wave compared with control ewes during the same time frame. Therefore, P4 appears to be a key endocrine signal governing the control of periodic increases in serum FSH concentrations and the number of follicular waves in cycling sheep.

scholarly journals Histological and steroidogenic changes in dominant ovarian follicles during oestradiol-induced atresia in heifers

Reproduction ◽  
2005 ◽  
Vol 129 (5) ◽  
pp. 611-620 ◽  
Author(s):  
Christopher R Burke ◽  
Horacio Cárdenas ◽  
Martin L Mussard ◽  
Michael L Day
Keyword(s):  
Treatment Initiation ◽  
Follicular Development ◽  
Pulse Amplitude ◽  
Treated Group ◽  
Ovarian Follicles ◽  
Assay Method ◽  
New Wave ◽  
Follicular Wave ◽  
The Status ◽  
Cell Layers

Histological and steroidogenic changes within dominant ovarian follicles (DFs) undergoing atresia following systemic administration of oestradiol benzoate (ODB) were characterized in beef heifers. At 5.6 ± 0.1 days after the onset of oestrus, heifers received 1 mg ODB i.m./500 kg body weight (ODB; n = 15) or served as controls (n = 15). Timing of treatment initiation was designated as hour (h) 0 on day (d) 0, and coincided with the presence of the DF of the first follicular wave (DF1). Within treatments, the DF1 was collected following ovariectomy in four animals at h 12, h 36 or after ultrasonic detection of a new wave (NW) of ovarian follicular development. In heifers of the NW groups (n = 7 per treatment), blood samples were collected at intervals of 20 min for 12 h beginning at h − 12, 0, 24 and 48 to characterize circulating LH patterns. Administration of ODB suppressed (P < 0.01) mean concentrations of LH at h 24 and h 48 by preventing (P < 0.05) the increase in LH pulse amplitude observed in controls, but had no effect on FSH. Follicular fluid (FF) concentrations of androgens and oestradiol were reduced at h 36 in the ODB-treated group. The diameter of the DF1 and the number of granulosa cell layers were also reduced in ODB-treated as compared with control heifers. Treatment differences were not observed in the proportion of apoptotic granulosa cells as assessed using the TUNEL assay method, and timing of a new wave of follicular development (d 4.6 ± 0.2) was similar (P > 0.1) among treatments. A prominent characteristic of oestradiol-induced atresia of the DF1 of the oestrous cycle in heifers was a loss in oestrogenic function associated with reduced LH support. However, the timing of new follicular development may be influenced by a factor(s) other than the status of the DF undergoing oestradiol-induced atresia.

scholarly journals Expression of estrogen receptors alpha (ERs α) and folliculogenesis profile in ovary of the rats ovarian hypofunction model

2021 ◽  
Vol 31 (1) ◽  
pp. 18-26
Author(s):  
Aulia Firmawati ◽  
Mitra Artha Kurnia Hutabarat ◽  
Herlina Pratiwi ◽  
Alibiruni Haryo
Keyword(s):  
Treatment Group ◽  
Ovarian Function ◽  
Follicular Development ◽  
Control Group ◽  
Reproductive Disorders ◽  
Test Analysis ◽  
Antral Follicles ◽  
Wistar Strain ◽  
Estrogen Binding ◽  
Hematoxylin Eosin

Ovarian hypofunction is one of the reproductive disorders that occur due to a decrease in ovarian function that causes animals to not experience heat. The purpose of this study was to determine the effect of GnRH antagonist hormone interventions on ovarian hypofunction model rats by looking at the expression of alpha ERs (ERs α) and the profile of folliculogenesis in the ovaries. This study used two groups of female Wistar strain rats, aged 8-10 weeks, bodyweight 150-180 grams and each group contained 10 animals. Intervention gave control group, without cetrorelix acetate intervention (placebo aqua dest sterile), treatment group with the induction of cetrorelix acetate 0.0135 mg/kg BW for 17 days. Observation of α ERs expression in the ovary was analyzed by immunohistochemical methods, and data were analyzed using T-Test analysis (α <0.05). Meanwhile, the folliculogenesis profile was analyzed by hematoxylin-eosin (HE) staining, then analyzed descriptively. The results of this study indicate that the treatment group given the intervention cetrorelix acetate dose 0.0135 mg/kg BW showed significantly different results compared to the control group. In the treatment group, the ERs α expression decreased by 82.7% compared to the control group and in the folliculogenesis profile, there was a decrease in follicular development from pre-antral follicles to antral follicles. Cetrorelix acetate interventions can have an effect on the inhibition of folliculogenesis and estrogen binding with ERs that cause anoestrous.

Estrous Cycle of Induced Ovulators: Lesson From The Camel — A Review

2018 ◽  
Vol 1 (2) ◽  
pp. 108-125
Author(s):  
Y Dauda
Keyword(s):  
Estrous Cycle ◽  
Ovarian Function ◽  
Assisted Reproductive Technologies ◽  
Current Knowledge ◽  
Reproductive Technologies ◽  
Wave Pattern ◽  
Follicular Wave ◽  
Calving Intervals ◽  
Camel Husbandry ◽  
Ovulatory Process

Camel, rabbit, cat, ferrets, minks, koala and meadow moles are induced ovulators requiring copulation to trigger the ovulatory process and the estrous cycle differs from that of other domestic animals. The estrous cycle in these animals composed of follicular recruitment, follicular growth, follicular maturity and follicular regression phase. These animals are variously reared as companion, fur-bearing and meat animals. Among these, the camel is the most valuable and classical induced ovulator which is rear not only for milk and meat, but as work animal and contributes effectively to the welfare of people in harsh and difficult environments. As a classical induced ovulatory, camelid has cycling receptivity with distinctive estrus but requires mating in order to ovulate. The other classes of induced ovulators like cats and ferrets require both the presence of male to achieve behavioral estrus and actual copulation to ovulate. The camel has good prospects of survival as a suitable livestock for projects of sustainable agriculture and animal production under harsh desert or arid conditions. However the reproductive nature of camels presents a huge challenge to camel husbandry. The natural constraints include the long period of attaining puberty, limited breeding season, difficulties in induced ovulation, long gestation period and inter-calving intervals. Efforts to improve the reproductive efficiency of the female camel are closely related to a better understanding of the folliculogenesis or follicular wave pattern. Many investigators might not be aware of the peculiar reproductive information available about this animal species. A working knowledge of ovarian function or estrous cycle will be of immense importance to the application of assisted reproductive technologies (ARTs) and enhancements of reproduction in camelids. This work presents the overview of estrous cycle in camel as a classical example of induced ovulators with the aim of providing current knowledge to the reader and to stimulate wider research interest in camel research and reproduction.

scholarly journals Effect of hyperandrogenism on ovarian function

Reproduction ◽  
2015 ◽  
Vol 149 (6) ◽  
pp. 577-585 ◽  
Author(s):  
Leandro M Velez ◽  
Maria F Heber ◽  
Silvana R Ferreira ◽  
Giselle A Abruzzese ◽  
Roxana M Reynoso ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Ovarian Function ◽  
Follicular Development ◽  
Female Rats ◽  
Control Group ◽  
Peroxisome Proliferator ◽  
Mrna Levels ◽  
Ovarian Steroidogenesis ◽  
Inflammatory Status

The objective of this work was to study the ovarian function when follicular development is induced during a hyperandrogenic condition. Female rats were injected with either equine chorionic gonadotropin (eCG group) to induce folliculogenesis or eCG together with DHEA to induce folliculogenesis in a hyperandrogenic condition (eCG+HA group). The control group was injected with vehicle. Ovarian mRNA levels of the peroxisome proliferator-activated receptor gamma (PPARγ) co-activator PGC1α, the PPARγ co-repressor NCoR, the main enzymes involved in the ovarian steroidogenesis (CYP17, 3β-hydroxysteroid dehydrogenase (3β-HSD), 17β-HSD, and CYP19A), and cyclooxygenase 2 (COX2) were evaluated only by real-time PCR. COX2 was evaluated by both real-time PCR and western blot. Serum steroid hormones and both the oxidative and inflammatory statuses were also quantified. We found that eCG-induced folliculogenesis induced increased mRNA levels of PGC1α and decreased those of NCoR when compared with controls. In addition, we found an increase in serum estradiol (E2) levels and enhanced mRNA expression of CYP19A. A pro-inflammatory status and a pro-oxidant status were also established. When folliculogenesis was induced in a hyperandrogenic condition, the mRNA levels of the PPARγ co-repressor NCoR remained higher than in controls and the pro-inflammatory and pro-oxidant statuses were enhanced. In addition, the enzymes involved in ovarian steroidogenesis were altered leading to the accumulation of testosterone and an unfavorable E2/testosterone ratio. These alterations led to abnormal follicular development.

227 SUPEROVULATION AND EMBRYO COLLECTION IN WOOD BISON DURING THE ANOVULATORY SEASON

2012 ◽  
Vol 24 (1) ◽  
pp. 226 ◽  
Author(s):  
J. M. Palomino ◽  
R. B. McCorkell ◽  
M. Anzar ◽  
M. R. Woodbury ◽  
N. Hawkins ◽  
...  
Keyword(s):  
Transvaginal Ultrasound ◽  
Bison Bison ◽  
Corpora Lutea ◽  
Chi Square ◽  
Release Formulation ◽  
Follicular Wave ◽  
Slow Release Formulation ◽  
Wood Bison ◽  
Wood Buffalo National Park ◽  
Disease Free

Brucellosis and tuberculosis are endemic in Wood Buffalo National Park, the largest reserve of wood bison (Bison bison athabascae) in Canada. Our goal is to produce and preserve disease-free embryos for the purpose of wood bison repopulation. This study was designed to determine if embryo collection is feasible in wood bison during the anovulatory season (May–July) and to test if progesterone priming is required for superovulation. A 2-by-2 design was used to determine the effectiveness of LH (Lutropin) or hCG (Chorulon) for induction of ovulation with or without intravaginal progesterone releasing device (PRID) in 32 wood bison cows. Follicular wave emergence was synchronized among bison by transvaginal ultrasound-guided follicle ablation. Synchronized bison were assigned to 4 groups: PRID+LH (n = 12), PRID+hCG (n = 4), no-PRID+LH (n = 12) and no-PRID+hCG (n = 4). A PRID was inserted on the day of follicular ablation in the respective groups. A single SC dose of 400 mg FSH (Folltropin) in a slow-release formulation was given the day after follicular ablation (i.e. on the expected day of a new follicular wave emergence, Day 0). The PRID was removed on Day 4 and either 25 mg LH or 2000 IU hCG was given IM on Day 5. Artificial insemination was done at 24, 36 and 48 h after LH or hCG treatment. Embryos were collected nonsurgically on Day 13 using commercial bovine equipment. Transrectal ultrasonography was done on Days 0, 5, 6, 7, 8 and 13 to record follicular and ovulatory responses. Count data (mean ± SEM) were analysed by two-way ANOVA and proportions by chi square. The number of ovulatory-sized follicles (≥10 mm) on Day 5 did not differ among groups (P = 0.33; Table 1). Ovulation rate (number of ovulations/number of follicles ≥10 mm) was greater in bison treated with hCG (P < 0.05; Table 1). The number of corpora lutea (CL) on Day 13 was greater in bison treated with hCG without a PRID (P < 0.05; Table 1). No differences in number of ova/embryos and transferable embryos were found among groups (P = 0.36 and P = 0.52, respectively; Table 1). In conclusion, progesterone priming (PRID) had no effect on ovarian superstimulation in wood bison in the anovulatory season. The ovulatory response was satisfactory only in bison treated with hCG. Embryo collection is feasible in wood bison, but the reasons for a low embryo collection rate in all groups remain unclear. Table 1.Response to superovulation and embryo collection in wood bison Funded by Advancing Canadian Agriculture and Agri-Food and Agri-Food Innovation.

224 A COMPARATIVE STUDY BETWEEN WOOD AND PLAINS BISON

2008 ◽  
Vol 20 (1) ◽  
pp. 191
Author(s):  
C. Lessard ◽  
J. Danielson ◽  
J. Thundatil ◽  
M. Woodbury ◽  
R. McCorkell
Keyword(s):  
Egg Yolk ◽  
Reproductive Technologies ◽  
Bison Bison ◽  
Animal Origin ◽  
Accessory Glands ◽  
The Status ◽  
Reproductive Techniques ◽  
Wood Bison ◽  
Student’S T ◽  
Student’S T Test

In Canada, brucellosis and tuberculosis threaten an estimated 4500 wood bison (Bison bison athabascae), a species considered at risk by the Committee on the Status of Endangered Wildlife In Canada (COSEWIC). To help rescue this species, our Wood Bison Reproductive Research group proposes to employ advanced reproductive technologies. Unfortunately, little is known about the reproductive physiology of the wood bison, which hinders the application of these reproductive technologies. In order to modify advanced reproductive techniques developed in cattle for use in wood bison, the large amounts of semen, embryos, and oocytes from wood bison required are not available. The purpose of this study was to compare semen collected from the more abundant and closely related plains bison (Bison bison bison) with that of wood bison. Semen from 3 wood and 4 plains bison were collected by electro-ejaculation during the summer of 2007. Andrological parameters of morphology and motility were recorded on fresh semen, extended semen, and post-thawed semen samples. A Student's t-test was used to compare the results of these two groups. Semen was cryopreserved using two commercially available cryopreservation media (Andromed and Triladyl, Minitube Canada, Ingersoll, Ontario, Canada). Sperm morphology and motility were not different between electro-ejaculated samples from plains and wood bison (P > 0.05). Also, no difference was found in the survival rate of sperm from the electro-ejaculated samples between plains and wood bison after freezing and then thawing using an egg-yolk based extender (Triladyl) or an extender containing no products of animal origin (Andromed). A difference between cryopreservation media was found; post-thaw motility of Triladyl-treated sperm was higher (29%) than that of the Andromed-treated sperm (12%). Due to lack of previous success with preserving electro-ejaculated semen in media free of animal-origin products, motility assays were performed to evaluate if spermatozoa retrieved from epididymides of plains bison can be cryopreserved in Andromed. Interestingly, cyropreserved epididymal spermatozoa had a higher motility than cryopreserved electro-ejaculated sperm after freezing-thawing procedures using a medium containing no products of source animal (respectively, 30% v. 7%). This result suggests that there may be a factor secreted by the reproductive accessory glands that interferes with the post-thaw survivability of bison sperm. In conclusion, this study supports the hypothesis that semen from plains bison behaves similarly to that of wood bison semen during cryopreservation and therefore could be used to establish protocols for advanced reproductive technologies in wood bison. This project was supported by Canadian Adaptation and Rural Development in Saskatchewan.

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