Bison Calves Research Articles

Serum IgG Immunoglobulin Levels are Associated with Reduced PCR Detection of Mycoplasma bovis in Naturally Infected American Bison (Bison bison).

Mycoplasma bovis (M. bovis) is an important pathogen of American bison (Bison bison), associated with high morbidity and mortality epizootics of respiratory and reproductive disease. Despite the significant negative impact on bison health, little is known about the kinetics of disease and the host immune response to infection. To address these questions, a cohort of bison calves was created and serially sampled 5 times, once every 2-3 mo, over a 12-mo period. At each sampling period nasal swab samples were collected and tested by PCR for the presence of M. bovis. Serum samples were also collected and assessed for M. bovis-specific antibodies using both a commercial and an in-house ELISA. Overall, 19/41 bison (46.3%) had positive PCR tests, and 31/41 (75.6%) were seropositive. Over the course of the study, the frequency of PCR-positive nasal swabs and the ELISA scores decreased, although serum samples remained positive for at least 6 mo following the final positive PCR test. Bison were grouped according to results from the in-house ELISA into high-responder (n=7), low-responder (n=5), and seronegative (n=7) groups. M. bovis-specific IgG antibody levels were significantly elevated in the high-responder group compared to the low-responder and seronegative groups. The differences were statistically significant for 3/5 sampling periods. A trend toward increased IgG2 levels was observed in the high-responder group. High total IgG responses correlated with a decline in positive PCR tests from nasal swabs. These data provide evidence that a strong humoral response is beneficial and is probably involved in the clearance of M. bovis from bison.

339 An Evaluation of the Effects of Feeding an Exogenous Fibrolytic Enzyme Product on the Growth Performance and Apparent Nutrient Digestibility of Growing Bison Calves Fed in a Commercial Feed Yard

Abstract While exogenous enzyme supplementation has been tested in ruminants as early as the 1960’s, industry adoption of such technologies has been slow. With high feed costs, technologies such as feed enzyme could potentially help producers to lower the production cost by improving feed efficiency. A 69-day growing experiment was conducted at a commercial feed yard in Western NE using bison calves [n = 228; initial body weight (BW) = 269 kg, SD = 41 kg] to determine the effects of supplementation of an exogenous fibrolytic enzyme from T. reesei on calf dry matter intake (DMI), growth performance and nutrient apparent digestibility. A completely randomized design was utilized with two treatments, control (CON) or enzyme (CX), and four pens, with calves assigned randomly to pen and pen assigned to TRT (48 to 66 calves per pen). Individual calf BW were obtained on day 0, day 35, and day 69. The DMI was measured daily by pen, with feed offered adjusted daily and fecal samples were composited and analyzed on pen-basis. Data were analyzed using JMP statistical software, with initial BW included as a covariate in the analyses. Average daily gain and DMI in calves fed the CX treatment was 7% greater (0.895 vs. 0.830 kg/d; P = 0.02), and 11% less (7.83 vs. 8.75 kg/d; P = 0.02) than in calves fed the CON treatment, respectively, resulting a 18% numeric improvement in feed efficiency for calves fed the CX treatment compared with calves fed the CON treatment. Apparent starch digestibility tended to improve (P = 0.07) by 15% in calves fed the CX treatment compared with calves fed the CON treatment, while apparent neutral detergent fiber (NDF) digestibility (as a percent of NDF) was numerically improved by 9% in calves fed the CX treatment compared with calves fed the CON treatment. Although the mode of action warrants further investigation, these data suggest that feeding an exogenous fibrolytic enzyme product may be beneficial for growing bison calves, likely in part because of greater apparent nutrient digestibility.

171 Sex-Sorted Sperm Used for Fixed-Time Artificial Insemination and in Vitro Fertilization in Wood Bison

Abstract Wood bison (Bison bison athabascae) are a threatened species native to Canada. In a conservation setting such as zoos, females are preferred over males and sex-sorted sperm may help skew the proportion of females born. The objective of this study was to determine the efficacy of sex-sorted sperm in fixed-time artificial insemination (FTAI, Experiment 1) and in vitro fertilization (IVF, Experiment 2). In Experiment 1, females in bison herds at the University of Saskatchewan and Toronto Zoo were synchronized with 3.3 mg estradiol-17ß + 50 mg progesterone and given a progesterone-releasing intravaginal device for 8 days. At device removal, bison were given 500 µg of cloprostenol, and 72 h later were given 2500 IU human chorionic gonadotropin (hCG) and inseminated with either sex-sorted or conventional sperm. A second insemination occurred 24 h after hCG. Pregnancy diagnosis and fetal sexing was done by transrectal ultrasonography at 30- and 70-days post-AI, respectively. In Experiment 2, cumulus oocyte complexes collected transvaginally from live bison were fertilized in vitro with either sex-sorted or conventional sperm. Cleavage and embryo rates were determined at 3- and 7-days post fertilization, respectively. Proportional data were compared by chi-square. In Experiment 1, there was no effect of herd (P=0.17) or sperm (P=0.68) on pregnancy per AI (P/AI) at 30 days (total=25/51 [49%]). The proportion of female calves was greater in the sex-sorted than conventional group (9/10 [90%] vs 3/11 [27%]; P< 0.01). In Experiment 2, the cleavage (122/222 [55%] vs 62/94 [66%];P=0.07) and embryo rate (18/222 [8%] vs 14/94 [15%]; P=0.07) tended to be lower in the sex-sorted than the conventional group. In summary, sex-sorted sperm increased the proportion of female bison calves born following FTAI. Future efforts will include improving embryo production rates following IVF with sex-sorted sperm. Funding provided by Toronto Zoo, Mitacs, and STGenetics.

Toxocara vitulorum infection in European bison (Bison bonasus) calves from Central Germany.

Whitish roundworms were found in the faeces of a female (3months old) and a male (1month old) European bison calf from an animal park in Central Germany. Since the faeces samples were not assignable to the individual animals, it is not certain if both calves were infected. The worms were identified as Toxocara vitulorum by morphological and molecular analysis, and a treatment with doramectin was initiated. To monitor the success of the therapy, faecal samples were examined before and after treatment by combined flotation/sedimentation technique, followed by a quantitative McMaster analysis in case of positive results. Additionally, stages of several Eimeria species and Trichuris sp. were found. Eggs of T. vitulorum were detected one week after application of doramectin, so, a second treatment was performed. However, no eggs of T. vitulorum were found at the time of the second treatment. Because of the difficulty of T. vitulorum eradication in infected herds, further investigations in the following year will be conducted.

Cryopreservation of bison semen without exogenous protein in extender and its fertility potential in vitro and in vivo following fixed-time artificial insemination

Successful cryopreservation of bison semen is fundamental for restoration of genetic diversity in Canada’s wood bison. Conventional bovine semen extenders contain animal products, such as egg yolk and milk, which are undesirable because of biosecurity risks and undefined composition. In this study, we examined the efficacy of an exogenous protein-free extender containing cholesterol-cyclodextrin complex (CC) to cryopreserve bison semen. The study also provided an opportunity to determine the effectiveness of different ovulation synchronization protocols for fixed-time artificial insemination in bison. Semen was collected from wood bison bulls via electroejaculation and cryopreserved in either Tris-egg yolk-glycerol (called ‘TEYG’) extender or pretreated with CC (2 mg/mL semen) and diluted in Tris-glycerol (collectively called ‘CC-TG’) extender. Post-thaw sperm motion characteristics and in vitro fertilization of cattle oocytes confirmed that CC alone without egg yolk protected bison sperm during cryopreservation process. In the first fertility trial, however, no pregnancy was obtained following fixed-time artificial insemination of bison cows with CC-TG extender. In a follow-up trial, low concentration of CC (1 mg/mL semen) resulted in better post-thaw sperm motion characteristics, fertility rate, and birth of live calves following fixed-time artificial insemination. Results showed that 1 mg CC/mL semen completely replaced egg yolk in bison semen extender. In addition, both follicular ablation and steroid treatment protocols provided ovulation synchrony to permit successful application of fixed-time artificial insemination in bison. This is the first report on the birth of live bison calves following fixed-time artificial insemination using semen cryopreserved in a defined extender.

Usefulness of PCR-RFLP of 18S rRNA gene for rapid post-mortem diagnostics of highly pathogenic Eimeria spp. (Apicomplexa: Eimeriidae) of European bison, Bison bonasus L. with histopathological correlation.

Eimeria spp. infection was investigated in 10 free-roaming European bison aged three months to 26 years by anatomopathological, histopathological, coproscopic and PCR-RFLP examination. The coproscopic study identified Eimeria oocysts in the faeces of five bison. The most prevalent morphotypes were E. bovis, present in all positive samples, and E. zuernii, in all but one. Additionally, mixed infections consisting of E. bovis, E. zuernii, E. alabamensis, E. auburnensis, E. canadensis, E. cylindrica, E. ellipsoidalis and E. subspherica were diagnosed in two bison calves. Besides being the most prevalent form, E. bovis also demonstrated the highest OPG (2,750). The presence of oocysts in the faeces was associated with those of macrogamonts, microgamonts and oocysts in the epithelium of the large intestine. Intestinal coccidiosis associated with lymphoplasmacytic enteritis was observed in many bison, not only those with positive OPG. Four animals with negative coproscopy results demonstrated early-stage gametogony in the large intestine; one case presented no endogenous stages of coccidians in the histopathological sections of the intestine, nor oocysts in the faecal samples. A 530 bp product of E. bovis 18S rDNA (GenBank: MK951685) was obtained from both the colon wall and oocysts; this was subjected to PCR-RFLP analysis based on AluI and Hin1II (NlaIII) restriction enzymes. Both samples yielded a consistent seven-band pattern, four of which (270 bp, 40 bp, 180 bp and 84 bp) were expected, and the other three represented undigested fragments. The obtained digestion pattern is indicative of Eimeria spp. infection, and can serve as a first-step diagnostic approach in detection of infection. The result of computer-based virtual digestion of the PCR product suggests that double digestion with Mval (BstNI) and KpnI restriction enzymes may be used as a second-step tool to distinguish between E. bovis, E. zuernii and E. alabamensis, all of which are highly-pathogenic species.

Past the Boardwalk

Past the Boardwalk Courtney Kersten (bio) Idaho was burning when Gordon and I met. Smoke blew into the city streets, blocked the sun, and crept through our bedroom windows. I would wake, lungs taut and tender, watch the smoke waft thick against the ceiling, and smear my nose against my palm, gray mucus a streak. For weeks after the smoke cleared, my chest would suddenly spasm and recede. A residual ember. I wondered if this was what it would be like for a ghost to wrap its translucent arms around you and squeeze. I thought it might be an omen—meeting Gordon and the smoke and the pains. He was dangerous. I should run. Knowing him was bad. But when I buried my nose in his chest and breathed, I smelled nothing but cigarettes and soap. When the smoke cleared, and he still remained—sturdy and serene like a river stone—an unfettered amour blossomed within me. It was then, nestled against his sternum, that I invited him, Come to the desert with me this summer—meet me there. As I felt him inhale to say yes, the first ribbon of anxiety unfurled within me. ________ Idaho is dark months later when I leave for the Great Basin. In the night, I drive from Moscow to Lapwai, from Cottonwood to Grangeville, from White Bird to Slate Creek, a photograph of my mother at twenty-eight, the same age as me, fidgeting on the dashboard. In the photo, she stands in knee-high cheat grass at the base of a taupe-colored mountain in Hells Canyon, Idaho. I want to see where she stood nearly thirty years ago; before she was a mother; before she could imagine a body revolting against itself; before she was old enough, I imagine, to truly conceive of her demise. I drive on the dirt road until I can go no farther, slip the photo in my back pocket, and as light spills into the valley, I walk the trails leading to [End Page 83] the Snake River. Tumbling hills unfold while grasshoppers, fat and wild, shudder across the trail. I imagine my mother walking beside me, and my lungs contract. ________ Only days before I left, a young man died in Yellowstone National Park. He went to the thermal hot springs bubbling at nearly 200 degrees Fahrenheit. He ignored the pamphlets. He ignored the instructions from park rangers. He ignored the smell of sulfur. He walked past the warning signs, the rails, the boardwalk. He walked into the steam. He heard the ground beneath him crackle or felt it waver and give; he slipped and fell into an acidic mudpot. He capsized and screamed. Gasped. Clawed for his life until the earth swallowed him. He boiled to death. No remains left to recover. Twenty-two people have died in the waters since 1890. A month earlier, another tourist thought a bison calf looked cold, put it in his car, and drove off with it until he was stopped by park rangers. The calf subsequently died. Meanwhile, a woman tried to pet a bison near the Old Faithful geyser, and another visitor inched closer to an elk, camera poised in her hand, until it charged. She scrambled backward, trees reeling above. The parks are a study in juxtaposition: cheery foldable maps, souvenir plush animals, and the emblematic park ranger hats alongside the warnings to carry bear spray, to stay on the trail, to know that animals can and will charge, to know that you visit the park at your own risk. Standing in a visitor's center or on a trail, the line between safety and danger can appear porous. Maybe you touch that boundary and walk away. Maybe you touch it and leave with a scar. Or maybe you touch it and never come back. But how do you know when to proceed and when to retreat? When to walk into the steam and when to turn around? When do you snap that shot and when do you drop your camera and run? ________ The Great Basin is all wind when I arrive. Dry and unyielding. I've come for a job to curate the...

5 Live Offspring Produced from Reproductive Material Recovered During the Annual Cull of Bison from Yellowstone National Park

Bison from Yellowstone National Park (YNP) have a unique genetic history that makes them a conservation priority for the species. Unfortunately, there is a high prevalence of the zoonotic disease brucellosis in the herd. Part of the management strategy for controlling the disease and herd size in YNP is an annual culling process. This culling may result in loss of valuable genetic material and, until now, has been a missed opportunity to recover and preserve those genetics. The goal of this project was to demonstrate the feasibility of producing healthy offspring from reproductive material collected during the nonbreeding season from bison postmortem and to determine effects of donor parameters, including sexual maturity and pregnancy status on IVF outcomes. Oocytes were collected from ovaries harvested from bison within 2 h of slaughter during winters of 2014 to 2017 for use in in vitro embryo production (IVP). Frozen-thawed semen from 7 YNP bulls collected via electroejaculation in vivo or from epididymal flushes postmortem was used for IVF. Embryos were produced using standard cattle IVP procedures. On Days 7, 7.5, and 8 of in vitro culture, embryos were assessed for developmental stage and quality, and Grade 1 and 2 embryos were vitrified on Cryotops® (Kitazato, Tokyo, Japan) in a two-step equilibration process. Embryos were then stored until the breeding season when they were warmed, cultured for 6 h, evaluated for survival, and transferred to healthy bison recipients. Data were analysed using a Student’s t-test. Age did not affect the mean number of oocytes collected from a mature female (n = 254) v. juvenile (n = 27; 24 ± 16 v. 24 ± 13), embryo cleavage rates (54 ± 24% v. 45 ± 24%), or the rate of blastocyst development (8 ± 12% v. 7 ± 8%, respectively). Pregnancy status did have a significant effect on the number of oocytes collected per female (pregnant 22 ± 15%, n = 258; nonpregnant 26 ± 20%, n = 82; P = 0.04) and the percent of oocytes that cleaved (pregnant 56 ± 23%, n = 189; nonpregnant 47 ± 24, n = 61; P = 0.005). No difference was detected in the percent of embryos that reached the blastocyst stage of development (pregnant 8 ± 10%, nonpregnant 8 ± 15%). In August 2016, 12 embryos were transferred singly or in pairs to 10 recipient bison synchronized using a standard synch protocol. Ten days following removal of the CIDR, embryos were transferred to recipient bison with a palpable corpus luteum. In spring of 2017, a healthy female calf was born to a recipient who had received 2 Grade-2 blastocysts as graded at the end of the 6-h incubation period. The genetic dam of the calf was a pregnant adult bison cow. This calf demonstrates that live offspring can be generated from oocytes collected from bison postmortem in the nonbreeding season. Although cleavage rates were higher with oocytes from pregnant bison, viable embryos were generated from nonpregnant adults and juvenile females, warranting continued collection of their oocytes and banking of resulting embryos. To our knowledge, this is the first bison calf produced by in vitro production using postmortem reproductive material.

Клинический случай проявления ценуроза церебрального у зубра

Objective of research: the analysis of Coenurus cerebralis found in the brain of a bison from
 Prioksko-Terrasny Nature Biosphere Reserve of the Moscow region.
 Materials and methods. We have conducted the euthanasia and dissection of the brain of a
 bison calf due to manifestation of clinical neurological symptoms.
 Results and discussion: After brain dissection, a strange large dumb-bell shaped vesicle was
 revealed in the brain tissue. On the inner surface of the vesicle the protoscolexes of helminthwere
 found. The surrounding brain tissue was significantly atrophied, cerebral meninges were swollen,
 and fissures were smoothed.
 To confirm the species belonging of the parasite, a part of surface with 50 protoscolexes was
 fed to a 6 mo. aged dog. 2,5 months later, Тaenia multiceps proglottids were revealed in dog’s
 feces, which confirmed the belonging of Coenurus cerebralis. It was found, that the bison might
 be one of the intermediate hosts for this helminth.

Influence of inbreeding on the incidence of cryptorchidism in males of Lowland-line bison

The aim of this study was to find whether the coefficient of inbreeding is correlated with the incidence of cryptorchidism in the Białowieża line of bison. Our study included 605 male European bison Bison bonasus (L.) born between 1971 and 2015 in the Białowieża Forest. The animals were free-ranging as well as from captive breeding programs. Among the animals culled, there were 144 European bison calves. The calves were not considered in the research, because the descending of the testes in European bison may not occur until a year after birth. The study period, from 1966 to 2015, was divided into 5 decades. The number of male European bison born in each decade was recorded, as well as the number of cryptorchidism cases identified through necropsy in these animals. The percentage of incidence of cryptorchidism among them was calculated for every decade. Subsequently, the Pearson correlation coefficient was calculated between the number of cryptorchidism cases and the coefficient of inbreeding. In 461 male European bison older than 1 year, there were 18 cases of cryptorchidism. In the animals born in the first decade, two autopsical cases of cryptorchidism (0.045%) were recorded, and 4 cases of cryptorchidism (0.03%) were found in the animals from the second decade. Among the bison born in the third decade, there were no cases of cryptorchidism. In the fourth decade, 7 cases of cryptorchidism (0.071%) were diagnosed, and among the bison born during the fifth decade, there were 5 cases (0.111%). The Pearson correlation coefficient suggests that, as the value of the coefficient of inbreeding rises, there is an increase in cryptorchidism cases in male European bison.

Superovulation and embryo transfer in wood bison (Bison bison athabascae)

Two experiments were done to develop an effective superovulatory treatment protocol in wood bison for the purpose of embryo collection and transfer. In experiment 1, donor bison were assigned randomly to four treatment groups (N = 5 per group) to examine the effects of method of synchronization (follicular ablation vs. estradiol-progesterone treatment) and ovarian follicular superstimulation (single slow-release vs. split dose of FSH). Recipient bison were synchronized with donor bison by either follicular ablation (N = 8) or estradiol-progesterone treatment (N = 9). In experiment 2, bison were assigned randomly to four treatment groups (N = 5 per group) to examine the ovarian response to two versus four doses of FSH, and the effect of progesterone (ovarian superstimulation with or without an intravaginal progesterone-releasing device). Donor bison were inseminated with fresh chilled wood bison semen 12 and 24 hours after treatment with GnRH (experiment 1) or LH (experiment 2). The ovarian response was assessed using ultrasonography. In experiment 1, the number of large follicles (≥7 mm) increased in response to both FSH treatments, but the diameter of the largest follicle detected 4 and 5 days after the start of ovarian superstimulation was greater in bison treated with a single dose of FSH than in those treated with two doses (P < 0.05). A total of 10 ova and/or embryos were collected. One blastocyst was transferred to each of five recipient bison resulting in the birth of two live wood bison calves. In experiment 2, two doses of FSH resulted in a greater number of large follicles (≥9 mm) on Days 4, 5, and 6 (P < 0.05) after beginning of superstimulation (Day 0), and more ovulations than four doses of FSH (11.2 ± 2.4 vs. 6.4 ± 0.8; P < 0.05). Embryo collection was performed on only five donors, and a total of 19 ova and/or embryos were recovered. In summary, fewer FSH treatments were as good or better than multiple treatments, consistent with the notion that minimizing handling stress improves the superovulatory response in bison. Follicular ablation and estradiol plus progesterone treatment were effective for inducing ovarian synchronization in embryo donor and recipient bison, and an intravaginal progesterone-releasing device during superstimulatory treatment did not influence the superovulatory response or embryo collection. Delaying ovulation-inducing treatment (GnRH or LH) to 5 days after superstimulatory treatment resulted in a greater number of ovulations and improved embryo collection efficiency (experiment 2). Embryo collection and transfer resulted in live offspring from wild wood bison.

Xenografting of testis tissue from bison calf donors into recipient mice as a strategy for salvaging genetic material

The objective was to evaluate the long-term outcome of testis tissue xenografting from neonatal bison calves as a model for closely related rare or endangered ungulates. Testis tissue was collected postmortem from two newborn bison calves (Bison bison bison) and small fragments of the tissue were grafted under the back skin of immunodeficient recipient mice (n = 15 mice; eight fragments/mouse). Single xenograft samples were removed from representative recipient mice every 2 mo after grafting (for up to 16 mo). The retrieved xenografts were evaluated for seminiferous tubular density, tubular diameter, seminiferous tubular morphology, and identification of the most advanced germ cell type. Overall, 69% of the grafted testis fragments were recovered as xenografts. Xenografts weight increased (P < 0.02) approximately four-fold by 2 mo and 10-fold by 16 mo post-grafting. In testis xenografts, gradual maturational changes were evident, manifested as the first detection of the following at the times specified: seminiferous tubule expansion, 2 mo; spermatocytes, 6 mo; round spermatids, 12 mo; and elongated spermatids, 16 mo. Furthermore, there were differences between the two donor calves regarding the efficiency of spermatogenesis in xenografts. The timing of complete spermatogenesis approximately corresponded to the reported timing of sexual maturation in bison. This study demonstrated, apparently for the first time, that testis tissue xenografting from neonatal bison donors into recipient mice resulted in testicular maturation and complete development of spermatogenesis in the grafts.

Surgical Repair of a Cleft Palate in an American Bison (Bison bison)

A 4-mo-old bison (Bison bison) was evaluated and treated at a university veterinary hospital for a cleft defect in the hard and soft palate. Using a mandibular symphysiotomy approach, the palatal defect was repaired with a Z-plasty pattern in the soft palate and mucoperiosteal flaps in the hard palate. A small area of dehiscence in the rostral aspect of the hard palate, and aspiration pneumonia, were complications, but the bison calf recovered with medical management. Even though this surgical procedure has a high potential for complications, the described technique allowed return to normal feeding and resolution of the aspiration pneumonia by 14 mo postsurgery.

Coyote, &lt;em&gt;Canis latrans&lt;/em&gt;, Predation on a Bison, &lt;em&gt;Bison bison&lt;/em&gt;, Calf in Yellowstone National Park

We observed a single adult male Coyote (Canis latrans) kill a Bison (Bison bison) calf in Yellowstone National Park. The predation is, to our knowledge, the only direct and complete observation of a lone Coyote capturing and killing a Bison calf. The bison calf had unsuccessfully attempted to ford a river with a group and subsequently become stranded alone in the territory of a six-year-old alpha male Coyote.

Occurrence and Molecular Characterization of Cryptosporidium and Giardia in Captive Wild Ruminants in Belgium

Both Cryptosporidium and Giardia are frequently found in the stool of domestic ruminants, especially young animals. Wild ruminants are also host to these protozoa, but the prevalence of these parasites in both free-ranging and captive nondomesticated ruminants needs to be further investigated. Moreover, the role of wild ruminants serving as reservoirs for these zoonotic parasites remains unclear. Therefore, a cross-sectional survey was conducted to estimate the occurrence of Cryptosporidium and Giardia in captive wild ruminants younger than 6 mo and to determine the potential of these animals to serve as reservoirs for these zoonotic parasites. A total of 67 captive wild ruminants belonging to 21 different animal species at the Antwerp Zoo (Belgium), along with 82 American bison (Bison bison) on a commercial breeding farm, were sampled for the detection of Cryptosporidium and Giardia, using a commercial immunofluoresence assay (Merifluor Cryptosporidium/Giardia IFA). The Cryptosporidium prevalence was 7.5% in the Antwerp Zoo animals and 3.7% in the bison from the breeding farm. All but two of the Cryptosporidium-positive animals were younger than 1 mo of age. Molecular characterization by amplification of the 70-kDa heat-shock protein and the 18S ribosomal DNA gene identified Cryptosporidium parvum in four animals of the Antwerp Zoo. The prevalence of Giardia was 8.9% in the Antwerp Zoo animals and 23.2% in the bison calves. Most Giardia-positive animals were older than 1 mo of age. Molecular characterization on the beta-giardin gene and the triose phosphate isomerase gene identified Giardia duodenalis assemblage A in the Antwerp Zoo and both G. duodenalis assemblage A and assemblage E in the bison calves. These findings indicate that both protozoan parasites are prevalent in captive wild ruminants and that these animals can serve as a potential reservoir for zoonotic transmission.

Immune responses after oral inoculation of weanling bison or beef calves with a bison or cattle isolate of Mycobacterium avium subsp. paratuberculosis.

Paratuberculosis is endemic in domestic and wild ruminants worldwide. We designed the following study to compare host immune responses and pathologic changes in beef calves and bison calves after challenge with either a cattle or bison (Bison bison) strain of Mycobacterium avium subsp. paratuberculosis. In the first part of the study, six bison and six beef calves were orally inoculated with a cattle isolate of M. avium subsp. paratuberculosis over a 2 wk period. In the second part, an additional six bison and six beef calves were similarly inoculated with a bison strain of M. avium subsp. paratuberculosis. Throughout each of the studies, blood and fecal samples were taken monthly for a 6 mo infection period. Tissue samples were obtained at necropsy for culture and histopathologic analyses. Results from this study demonstrated that bison calves were more susceptible to tissue colonization than beef calves after challenge with the cattle isolate and, conversely, that beef calves were more susceptible to the bison strain of M. avium subsp. paratuberculosis. Although lesions were minimal they were most apparent in the jejunum and distal ileum. Interferon-gamma (IFN-gamma) responses were noted in some calves by 1 mo postinoculation and were sustained longer in beef calves after challenge with the bison isolate. Antibody was not detected in either beef or bison calves during the 6 mo infection period. These results indicate that the host response to strains of M. avium subsp. paratuberculosis may differ between ruminant species.

Virologic investigations of free-living European bison (Bison bonasus) from the Bialowieza Primeval Forest, Poland.

We conducted virologic investigations on postmortem specimens from 261 free-living European bison (Bison bonasus) from the Bialowieza Primeval Forest, Poland collected between 1990 and 2000. Fifty-four of 94 males had balanoposthitis; none of the 167 female bison examined had reproductive tract lesions. Peripheral blood, swabs, and various tissues were analyzed for bovine viruses as well as for viral DNA by bovine herpesvirus 1 (BoHV-1) and bovine herpesvirus 4 (BoHV-4) specific polymerase chain reaction (PCR) technique. An infectious bovine rhinotracheitis like BoHV-1 strain was isolated from the spleen of a female bison calf and additionally was detected by nested PCR from splenic tissue. None of the bison had significant antibody titers against BoHV-1, bovine herpesvirus 2, BoHV-4, caprine herpesvirus 1, cervid herpesvirus 1, or bovine viral diarrhea (BVD) virus-1. However, low antibody titers in two animals indicate that this European bison population has been exposed to BVD virus or BVD-like viruses and BoHV-2.

Electronic aversive conditioning for managing wolf predation

Author(s): Shivik, John A.; Asher, Val; Bradley, Liz; Kunkel, Kyran; Phillips, Mike; Breck, Stewart; Bangs, Ed | Abstract: Electronic training collars have previously been used to condition captive predators not to attack livestock and other prey, but the use of aversive collars in actual management situations involving wild predators has not been scientifically evaluated and published. We adapted and tested commercially available dog training collars in an actual management situation involving wild wolves. Because we temporarily held wolves in captivity, we also discuss the use of pens as a tool that provides management flexibility. Three packs that had been implicated in killing livestock were held at a pen facility at the Flying D Ranch near Bozeman, Montana. Wolves from 2 packs were used in training collar experiments. We ran trials using bison calves, domestic cow calves, and hides to test equipment and the behavioral conditioning paradigm. In our program, we were unable to condition wolves not to attack livestock because of a variety of logistical and behavioral reasons. We concluded that temporarily holding wolves at a small, moderately accessible facility is of limited use for determining the utility of aversive conditioning as a wolf predation management technique. More research is necessary to effectively apply electronic training collars to wolf management. However, we determined that maintaining holding pens for wolves provides flexibility to managers in translocation efforts. Because wolves in our studies survived to reproduce, our collaborative efforts have made a significant contribution to wolf recovery.

WOLF–BISON INTERACTIONS IN YELLOWSTONE NATIONAL PARK

Abstract We studied interactions of reintroduced wolves (Canis lupus) with bison (Bison bison) in Yellowstone National Park. Only 2 of 41 wolves in this study had been exposed to bison before their translocation. Wolves were more successful killing elk (Cervus elaphus) than bison, and elk were more abundant than bison, so elk were the primary prey of wolves. Except for a lone emaciated bison calf killed by 8 1-year-old wolves 21 days after their release, the 1st documented kill occurred 25 months after wolves were released. Fourteen bison kills were documented from April 1995 through March 1999. All kills were made in late winter when bison were vulnerable because of poor condition or of bison that were injured or young. Wolves learned to kill bison and killed more bison where elk were absent or scarce. We predict that wolves that have learned to kill bison will kill them more regularly, at least in spring. The results of this study indicate how adaptable wolves are at killing prey species new to them.

Habituating Antelope and Bison to Cooperate With Veterinary Procedures

Undomesticated, wild, nonhuman animals with an excitable temperament frequently sustain injuries when handled for veterinary procedures such as blood sampling or injections. Both bison and antelope may become agitated when they are restrained, often resulting in broken horns. Also, antelope may panic when restraint is forced on them suddenly. This research group has successfully trained both Bongo and Nyala antelope to enter a box voluntarily for food rewards. While quiet, nonsedated antelope were standing in the box, blood samples were taken from their rear legs. Three Bongo antelope who had been conditioned to stand in the box had low cortisol levels that averaged 4.4 ± 3.4 ng/ml in a male and 8.5 ± 4.7 ng/ml in two females. The unsedated animals were held in the box for 10-20 min to allow cortisol levels to rise. These values were much lower than cortisol levels reported in the literature for restrained unsedated wild ruminants and domestic cattle who are not habituated to restraint. Because antelope are flighty animals, each new step in the conditioning process had to be introduced in very small steps to prevent panic. In another experiment, bison calves were trained to walk through the handling chutes for feed rewards. In both species, avoiding panic is important, especially in the early stages of training.