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The study aimed to propose sensitive, specific and easy pregnancy diagnosis for American Bison. Trans-rectal Palpation and Ultrasonography (TRPUS), concentration of Pregnancy Associated Glycoproteins (PAG), Progesterone (P4), Estrone (E1), Estrone-Sulfate (E1S) in serum and P4 and E1S in feces were compared. Immunoassay was used for PAG, whereas steroids were assayed using Liquid Chromatography coupled to Mass Spectrometry. Pregnancy and its period were retrospectively assessed after calving. Animals included were distributed as follows: 40 were non-pregnant, 27 were in their second and 15 in their third trimester of gestation. Fisher's test was used to determine sensitivity and specificity of TRPUS. Thresholds leading to best sensitivities and specificities for hormonal assays were determined using Receiver Operating Characteristic Curves. Although TRPUS requires contention, palpation skills, it was conclusive in 70.63 % of cases and good sensitivity (97.50 %) and decent specificity (83.33 %) were observed. Concentrations of PAG, P4, E1S and E1 in serum were higher in Pregnant animals (P), with thresholds giving decent specificity and sensitivity (lower sensitivity for E1 and E1S: 92.11 %; lower specificity for P4: 93.48 %). In feces, P4 and E1S were higher in P: pregnancy diagnosis using E1S assay in feces showed 100 % of sensitivity and specificity. In conclusion, assaying E1S in feces during the two last trimesters of American Bisons pregnancy is a sensitive and specific gestation diagnosis. Pregnancy diagnosis using TRPUS can be useful in ranches but requires contention and skill adaptation. Serum hormonal assays can help evaluating the pregnancy period but also require contention., Competing Interests: Declaration of Competing Interest All authors of the paper entitled “Diagnosing American Bison pregnancy during its two last trimesters: comparison between rectal palpation associated with ultrasonography, assay of Pregnancy Associated Glycoproteins and of steroids in feces or serum” have no conflict of interest to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Hematological and biochemical blood parameters are important tools for evaluating animals' health. They might be crucial in assessing the health of entire populations of wild animals, such as European bison (Bison bonasus). The aim of this study was to establish hematological and biochemical values for healthy European bison and to determine whether there were significant relations with age and sex. Blood samples were collected from 79 animals and tested according to generally accepted standards and the results were subjected to statistical analysis. Most of the age and gender-related correlations found in our study were predictable based on previous reports. Due to bone growth, juvenile animals have typically higher ALP and P concentrations relative to adults. Several age-related dependencies were surprising, like higher Na concentration in younger European bison. Determination of hematological and biochemical blood parameters of healthy European bison may significantly contribute to the further restitution of this endangered species., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Didkowska et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: This is the first report describing levels of APPs in European bison. Serum concentration of acute phase proteins (APPs) may be helpful to assess general health status in wildlife and potentially useful in selecting animals for elimination. Since there is a lack of literature data regarding concentration of APPs in European bisons, establishment of the reference values is also needed., Methods: A total of 87 European bison from Polish populations were divided into two groups: (1) healthy: immobilized for transportation, placing a telemetry collar and routine diagnostic purposes; and (2) selectively culled due to the poor health condition. The serum concentration of haptoglobin, serum amyloid A and α1-acid-glycoprotein were determined using commercial quantitative ELISA assays. Since none of the variables met the normality assumptions, non-parametric Mann-Whitney U test was used for all comparisons. Statistical significance was set at p < 0.05. Statistical analyses were performed using Statistica 13.3 (Tibco, USA)., Results: The concentration of haptoglobin and serum amyloid A was significantly higher in animals culled (euthanised) due to the poor condition in respect to the clinically healthy European bison. The levels of α1-acid-glycoprotein did not show statistical difference between healthy and sick animals., Conclusions: Correlation between APPs concertation and health status was proven, therefore the determination of selected APPs may be considered in future as auxiliary predictive tool in assessing European bison health condition., (© 2022. The Author(s).)

Background: The European bison is an endangered species, and as such it is extremely important to monitor herds for pathogens which can lead to reproductive failure. The aim of the present study was to determine the current prevalence of antibodies to pathogens known to potentially influence reproduction in European bison. Serum samples from 183 bison, originating from different parts of Poland, were tested using commercial ELISA tests for antibodies to Chlamydia spp., Coxiella burnetti, Leptospira interrogans, Neospora caninum and Toxoplasma gondii; the findings were compared between captive and main free-ranging herds, and with regard to the influence of demographic factors such as age and sex. The prevalence of seropositivity was also checked with regard to location and the animal species sharing it., Results: Chlamydia spp. antibodies were present in 48 out of 130 (36.9%) tested samples. Coxiella burnetii was found in one sample out of 178 (0.58%). N. caninum in 36 out of 172 (20.9%) and T. gondii in 23 out of 172 (13.4%). No sample was positive for leptospirosis. Neither sex nor age appeared to have a significant effect on the occurrence of antibodies to the identified species. The prevalence of Chlamydia spp. in the samples varied significantly according to location; however, similar frequency ranges were observed between free ranging and captive herds. In contrast, antibodies to N. caninum were more common in free-ranging herds than captive herds, with the highest frequency observed in the Bieszczady Mountains., Conclusions: Chlamydia spp., N. caninum and T. gondii might have a similar impact on the reproductive potential of European bison as they have on cattle. The high occurrence of antibodies to N. caninum in bison from the Bieszczady Mountains may be associated with the relatively high density of the wolf population in the area., (© 2021. The Author(s).)

Steroid concentrations in serum are fluctuating during pregnancy of many mammal species. The current knowledge about endocrinology of gestation is mainly based on immunoassays. However, the lack of specificity of these assays hampers the reliability of the results. In the present work, we developed and validated a methodology associating liquid chromatography (LC) and mass spectrometry (MS) to simultaneously quantify, with high specificity and accuracy, estrone-3-sulfate (E3S), progesterone (PRO), estrone (E1) and estradiol (E2) in serum of two different mammal species. The sample preparation procedure is based on a simple protein precipitation and a derivatization with dansyl chloride. After the chromatographical separation, compounds were analyzed with a triple-quadrupole mass spectrometer operating in multiple reaction monitoring. Mare and American bison serum samples were analyzed with the validated method and results were compared with concentrations measured with commercial radioimmunoassay (RIA), enzyme linked immunosorbent assay (ELISA) and chemiluminescent microparticle immunoassay (CMIA). Following these criterions: relative standard deviation <15% and relative bias <15%, lower limits of quantification of 0.5 ng/mL (E3S), 0.1 ng/mL (PRO) and 2 pg/mL (E1 and E2) were achieved. Most of the comparison between immunoassays and LC-MS showed poor correlation and proportional differences. Our LC-MS method is able to simultaneously quantify several steroid hormones with high specificity, accuracy and sensitivity in serum of two different mammal species. Our method constitutes a useful and performant tool for veterinary clinicians and LC-MS should thus be used to update and refine the current knowledge about the endocrinology of pregnancy in mammals., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The age-specific reference values for immunoglobulin (Ig) serum concentrations in European bison ( Bison bonasus ) are lacking. Identification of immune alterations that accompany normal physiological aging will help assist in development of better monitoring health programs. In the present study, the age-associated changes in concentration of IgG, IgM, and IgA in serum of apparently healthy European bison of various ages were studied. The quantities of IgA, IgM, and IgG were measured by the use of a commercial ELISA kit. The serum samples originating from apparently healthy European bison ( n = 206) were divided into the following age categories: (1) <1 year of age; (2) animals between 1 and 3 years of age; and (3) animals which have reached sexual maturity: (3a) animals between 4 and 8 years of age, (3b) animals between 9 and 15 years of age, and (3c) animals > 15 years of age. IgG was found to be predominant Ig in the serum regardless of the age of the animals. The significant positive correlation between IgG absolute and relative concentration and the age of animals was found. The absolute concentration of IgM did not differ significantly during the lifespan; however, the negative correlation was observed between percentage of IgM and European bison's age. IgA represented the least class of serum Ig. Total serum concentration of analyzed Ig also significantly increased with age. No gender-related differences were detected. Our findings represent a meaningful contribution to the studies on the immunity of European bison and effect of age on the immunoglobulin level. Our results would be useful for veterinarians and researchers in the studies with this animal's species., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this paper., (Copyright © 2020 Małgorzata Pomorska-Mól et al.)

A central goal for reintroduced populations of threatened wood bison ( Bison bison athabascae) is to maintain them free of diseases of concern, particularly bovine tuberculosis (caused by Mycobacterium bovis) and brucellosis (caused by Brucella abortus). A wood bison population in southwestern Yukon, Canada was reintroduced into the wild in 1988, but no health assessment has been done since then. To provide an initial assessment of the health status and, hence, the conservation value of this population, we serologically tested 31 wood bison (approximately 3% of the population) for pathogens of interest and obtained histopathology results for select tissues. We found no evidence of exposure to M. bovis or Brucella spp., but antibodies were present to bovine parainfluenza virus 3, bovine coronavirus, Leptospira interrogans, and Neospora caninum, with seroprevalences of 87, 7, 61, and 7% of the tested animals, respectively. Reintroduced wood bison in southwestern Yukon may be of high value for wood bison recovery because it is a large and geographically isolated population with no bacteriologic, histopathologic, or serologic evidence of exposure to Brucella spp. or M. bovis.

Blood species identification is an important challenge in forensic science. Conventional methods used for blood species analysis are destructive and associated with time-consuming sample preparation steps. Nuclear magnetic resonance (NMR) spectroscopy is known for its nondestructive properties and fast results. This research study presents a proton ( 1 H) NMR method to discriminate blood species including human, cat, dog, elephant, and bison. Characteristic signals acting as markers are observed for each species. Moreover, the data are evaluated by principle component analysis (PCA) and support vector machines (SVM). A 100% correct species recognition between human and nonhuman species is achieved using radial basis kernel function (RBF) and standardized data. The research study shows that 1 H NMR spectroscopy is a powerful tool for differentiating human and nonhuman blood showing a great significance to forensic science.

The performance characteristics of a newly developed liquid chromatography-mass spectrometry (LC-MS) method were validated and demonstrated to be fit for purpose in a pharmacokinetic and tissue depletion study of white-tailed deer and bison. Tulathromycin was extracted from bison and deer sera with acetonitrile or trifluoroacetic acid and K2 HPO4 (pH 6.8) buffer solution and cleaned up on a conditioned Bond-Elut cartridge. Tulathromycin, retained on the cartridge; it was eluted with methanol containing 2% formic acid, dried, re-constituted in methanol/1% formic acid, and analyzed by LC-MS. The limit of quantification (LOQ) of the method was 0.6 ng/mL in serum and 0.6 ng/g in tissue with RSDs ≤ 10% and accurate over the linear calibration range of 0.8-100 ng/mL for bison serum, 0.6-50 ng/mL for deer serum, 100-2500 ng/g for deer muscle tissue, and 500-5000 ng/g for deer lung tissue, all with coefficients of determination, r(2) ≥0.99. The validated method was used to quantify the concentration of tulathromycin residues in serum of bison and deer and selected tissue (lung and muscle tissue) samples obtained from 10 healthy, white-tailed deer that were administered the therapeutic dose approved for cattle (i.e., a single 2.5 mg/kg subcutaneous injection of tulathromycin in the neck). The deer were included in a tulathromycin drug depletion study. © 2016 Her Majesty the Queen in Right of Canada. Drug Testing and Analysis © 2016 John Wiley & Sons, Ltd., (© 2016 Her Majesty the Queen in Right of Canada. Drug Testing and Analysis © 2016 John Wiley & Sons, Ltd.)

Background: The European bison (Bison bonasus) is an endangered species. More information on its anatomy is needed as only few studies have been published. This study is the first report on the morphology of the coronary vessels. Given the anatomical similarity between the European bison and other ruminants, the results of this study can be applied to other species, including endangered ones., Results: The study was conducted on 70 hearts of European bisons of both sexes, aged 5-20 years, with an average body weight of 449 kg. A distinct view of subepicardial arterial vessels was obtained by filling them with dyed synthetic latex (LBS 3060) and Plastogen G. There was a division of the common trunk of the left coronary artery into the interventricular paraconal branch and the left circumflex branch in 63 individuals (90 %). In five individuals (7.1 %), the presence of a third vessel, which was a branch of the interventricular septum, was observed. There was a lack of a common trunk in two individuals (2.9 %). Ramifications of the interventricular paraconal branch to the wall of the left ventricle were significantly larger than those to the wall of the right ventricle. In 17 individuals (24.3 %), the right coronary artery extended into the subsinuosal interventricular branch., Conclusion: The blood supply to the heart in bisons is provided by the left and right coronary arteries. In all the studied specimens, the left coronary artery was better developed than the right coronary artery.

Tulathromycin is approved for the treatment of respiratory disease in cattle and swine. It is intended for long-acting, single-dose injection therapy (Draxxin), making it particularly desirable for use in bison due to the difficulty in handling and ease of creating stress in these animals. The pharmacokinetic properties of tulathromycin in bison were investigated. Ten wood bison received a single 2.5 mg/kg subcutaneous injection of Draxxin. Serum concentrations were measured by liquid chromatography-mass spectrometry (LC-MS) detection. Tulathromycin demonstrated early maximal serum concentrations, extensive distribution, and slow elimination characteristics. The mean maximum serum concentration (Cmax) was 195 ng/mL at 1.04 h (tmax) postinjection. The mean area under the serum concentration-time curve, extrapolated to infinity (AUC0-inf ), was 9341 ng · h/mL. The mean apparent volume of distribution (Vd /F) and clearance (Cls/F) was 111 L/kg and 0.4 L/h/kg, respectively, and the mean half-life (t1/2) was 214 h (8.9 days). Compared to values for cattle, Cmax and AUC0-inf were lower in bison, while the Vd /F was larger and the t1/2 longer. Tissue distribution and clinical efficacy studies in bison are needed to confirm the purported extensive distribution of tulathromycin into lung tissue and to determine whether a 2.5 mg/kg subcutaneous dosage is adequate for bison., (© 2015 John Wiley & Sons Ltd.)

A serological study of twenty three European bison (Bison bonasus) derived from Northern-East Poland for the seroprevalence of Mycobacterium avium subsp. paratuberculosis, Mycoplasma bovis, Mycoplasma mycoides subsp. mycoides SC, Mycoplasma agalactiae and Mycoplasma capricolum subsp. capripneumoniae was conducted. Only specific antibodies to M. bovis were detected in two animals (8.7%) which were connected with the clinical signs and macroscopic anatomopathological lesions.

The aim of the present study was to investigate the occurrence of Borrelia burgdorferi sensu lato DNA in a group of 120 wild bison (Bison bonasus) from the Bialowieza Primeval Forest in eastern Poland. The PCR technique revealed the presence of 16S RNA of Borrelia burgdorferi sensu lato in the blood of 16 out of 120 examined animals. DNA amplification by means of primers SC1 and SC2 gave a product with a size of 300-bp. The sequences of the PCR products obtained showed 100% homology with each other and 100% homology with B. burgdorferi s.1. 16S RNA gene DQ111061. Results of this study suggest that wild bison are important in maintaining agents of Lyme borreliosis, and that studies of reservoir competence of this species are indicated.

Ranched bison are typically less acclimated to handling than are domesticated livestock, suggesting that they might be more vulnerable to handling and transportation stressors. Grain-finished bison were slaughtered on-farm (n = 11), or held for 48 h, transported to a research abattoir, held in lairage for 18 h, and then slaughtered (n = 11). An additional group (n = 10) was sampled at a conventional fixed location abattoir. Measures included serum cortisol and corticosterone concentrations during on-farm handling and exsanguination, serum glucose, creatinine phosphokinase (CPK), aspartate aminotransferase (AST), and trim losses. Transport was associated with an increase in trim loss. On-farm, glucose was elevated, CPK was positively associated with handling order over 12 h, and corticosterone concentration, although lower than cortisol concentration, showed a greater response to prolonged disturbance. With appropriate on-farm handling facilities, the use of on-farm slaughter and mobile abattoir could avoid muscle damage and trim losses, and mitigate injuries sustained during handling and transport of bison.

The blood samples of 17 bison (7 cows, a heifer, a young bull and 8 calves) formed the basis for conducting analyses of blood plasma. The measurements were carried out by using ionoselective electrodes aided by a Hitachi 917 biochemical analyser. An interpretation of the results was possible due to comparison with the results of similar analyses completed in the United States. Many differences in blood chemistry values in bison bred at Kurozweki were found in comparison to bison from the US.

Blood was collected from bison that were selected between 1991 and 2001 for poor body condition, cachexia, lameness and balanoposthitis. Sera were tested for antibodies to bovine herpes virus type 1 (BHV-1), bovine viral diarrhoea virus (BVDV), foot-and-mouth disease virus (FMDV), parainfluenza virus type 3 (PI-3), Brucella abortus, Chlamydophila abortus, Coxiella burnetti, and Leptospira interrogans. The results of serological tests showed a prevalence of low titers of a serological reaction to Chlamydophila abortus (45.1%), bovine viral diarrhoea virus (29.5%), Leptospira interrogans (21.3%) and parainfluenza virus type 3 (13.9%). There were differences in the prevalence of antibodies to Ch. abortus between female and male bison. Futhermore, a relationship between age and antibodies to BVDV was observed in older bison. These results suggest that there is some transmission of bacterial and viral pathogens occurring between domestic and wild ruminants grazing in the same pastures in the peripherial areas of Bialowieza Primeval Forest.

Ninety-seven bison (39 males and 58 females) were culled out during three successive winter seasons. No infection with BHV-1 and BHV-5 or other viruses was detected by PCR and SN methods. Advanced pathological lesions observed in males exhibiting symptoms of posthitis/balanoposthitis are probably due to secondary infection by microorganisms present in the prepuce (Corynebacterium spp., Bacillus spp., Fusobacterium necrophorum, Staphylococcus spp. (coagulase negative) and Staphylococcus hyicus). Histopathological examinations of sections from prepuce and lips of pudendum showed the presence of Onchocercinae nematode (Onchocerca sp.). A comparison of biochemical and morphological blood parameters in the bison with or without lesions in the digestive (presence of parasites), respiratory, urinary and reproductive tracts revealed that the most variable parameter during reproductive organ disorder is the leukocyte count, while disorders in the urinary and digestive tracts coincided with the age of animals. In cases of digestive disorder most changes were observed in the number of neutrophils and concentration of urea. The number of red blood cells, monocytes, the level of alkaline phosphatase (AP) and hematocrit negatively correlated with age. Negative correlation was also observed between the number of neutrophils, level of creatinine and lymphocyte proliferation index. However, positive correlation was seen between erythrocyte sedimentation rate (Spearman's correlation coefficient), level of alanine aminotransferase (ALT) and protein, and age of the bison. Positive correlation was also observed between the lymphocyte count and lymphocyte proliferation index. The attempt to determine the reference values for blood biochemical and morphological parameters showed similarities to those of cattle.

The aim of this study was to find a safe and reliable alternative to Immobilon for the immobilization of (feral) cattle. A combination of xylazine, zolazepam-tiletamine and ketamine was tested in Limousin cattle, Scottish Highland cattle, and American bison. Bodyweight, induction time, arterial O2 saturation and the total downtime were measured. Arterial blood was taken for pH and blood gas analysis. The animals were then injected with atipamezole and the recovery time was recorded. A combination of 500 mg zolazepam, 500 mg tiletamine, 500 mg xylazine, and 1000 mg (10 ml) ketamine, administered in a dosage of 1 ml per 100-150 kg bodyweight (depending on the species), proved to be most reliable and effective. The combination resulted in a fast immobilization. In all animals slight respiratory depression was seen, which indicates that oxygen suppletion may be needed for long-lasting immobilization. After reversal of the xylazine component, almost all animals recovered within 4 minutes. No long term adverse effects were reported by the owners.

The prevalence of antibodies to Neospora caninum was examined in European bison (Bison bonasus bonasus L.) living in free and fenced areas in Poland. Sera of 320 European bison, different ages and sexes, from breeding areas in Poland were tested for N. caninum antibodies using ELISA test. Positive antibody responses were found in 23 bison (prevalence 7.3%). Additionally, all positive sera were tested by Western blot to verify the ELISA results. The Western blot results confirmed the presence of antibodies to Neospora tachyzoites antigens in all 23 sera tested. The antibodies were detected against a wide range of NC-1 tachyzoite antigens. The antibody responses were directed against proteins at: 9.5, 17, 21, 27, 31, 36.5, 38, 40, 43, 47, 48.5, 53.5 and 58 kDa. The most heavily stained bands had molecular weights of 9.5, 17, 27 and 58 kDa. The most important is that antibody to N. caninum was detected for the first time in sera from bison cow shot in 1988. It is the year of recognition of this protozoan parasite. Our results indicate strongly the presence of N. caninum in European bison in Poland and suggest that a sylvatic cycle of N. caninum can exist. However, further studies are needed to evaluate the existence of a sylvatic cycle of N. caninum. The study on the effect of the infection on the health status and conservation of European bison should be taken under consideration too.

The comparative analysis of genetic differentiations between three species of Bovinae--Bos taurus, Bison bonasus, Bison bison with the use of different types of molecular-genetic markers--genetical-biochemical (35 loci) and DNA markers (RAPD-PCR, ISSR-PCR) was carried out. It was shown, that the evaluation of interspecies genetic interrelations was connected more with the determined molecular-genetic markers (loci), included in analysis, than with the marker's belonging to certain type (protein polymorphism, variability of DNA repeat distributions).

From 168 European bison divided into four groups (group 1, 0-3-year-old males; group 2, 0-3-year-old females; group 3, mature bulls, over 2 years old; group 4, mature cows, over 3 years old) the serum lysozyme level was studied. The mean lysozyme level varied from 3.91 micrograms/ml in young males (group 1) to 4.02 micrograms/ml in young females (group 2) and mature bulls (group 3); the range was from 2.10 to 6.40 micrograms/ml (only in a few animals). Statistically significant differences between months were found only in young males (group 1).

Polymorphism of nine blood group systems was studied in three reproductive lines of auroch (European bison Bison bonasus), Belovezhskaya, Caucasian-Belovezhskaya, and Gornaya. All blood group systems analyzed were polymorphic; 50 out of the 57 antigens tested were detected. The number of detected blood group antigens in aurochs is comparable to that in breeds of domestic cattle. However, intrapopulation diversity, estimated with the mu test, is significantly higher in cattle than in aurochs. The lowest mu values were observed in line Belovezhskaya, which was founded by a small number of animals and has a high level of inbreeding. For the FV system, the amount by which heterozygotes exceeded the Hardy-Weinberg proportions was shown; this deviation was significant in all lines except Caucasian-Belovezhskaya. The excess of heterozygotes may be due to population processes that prevent the loss of genetic diversity in populations. The level of differentiation in the auroch lines was low. Similarity coefficients between the lines were higher than those between different stocks within a cattle breed.

Hematologic and blood chemistry parameters were measured in 149 free-ranging American bison (Bison bison) from Yellowstone National Park, Wyoming (USA). Additionally, histopathologic evaluations of lung, liver, spleen, kidney, and mesenteric and bronchial lymph nodes were made from ten animals. Forty-five fecal samples were screened for the presence of helminth ova. Leukopenia and markedly low blood urea nitrogen concentrations were the most notable differences observed from other bison populations. All tissues examined were essentially normal; there was evidence of moderate intestinal parasite burdens.

1. In the blood of 65 European bison divided into four groups (Group 1, 0-3-year-old males; Group 2, 0-3-year-old females; Group 3, mature bulls, over 3 years old; Group 4, mature cows, over 3 years old) the values of pH, pCO2, pO2, base excess and bicarbonate level were studied. 2. The studies were carried out in winter months, from mid-December to mid-April. 3. No significant differences in parameters studied were found between young males and females. 4. All indices found in mature bulls and cows showed significant differences between all other groups. 5. Most of parameters examined here in European bison are comparable with those found in other big ruminants.

An enzyme immunoassay for urinary pregnanediol-3 alpha-glucuronide (PdG) was evaluated for the indirect measurement of progesterone metabolites during the oestrous cycle and early pregnancy of uncaptured North American bison. Comparisons between plasma progesterone and urinary PdG, dose-response parallelism between the standard curve and diluted urine samples and high-performance liquid cochromatography revealed that PdG was a primary immunoreactive urinary metabolite of progesterone in bison. Urine samples were collected directly from the soil from 29 bison cows during the August rutting season and analysed for PdG. Eight bison cows demonstrated complete oestrous cycles ranging from 19 to 26 days (mean cycle length = 23.12 +/- 0.76 days) and behavioural oestrus among four of these cows correlated with PdG nadirs. Mean PdG nadirs were 63.62 +/- 21.61 ng/mg urinary creatinine (Cr) and mean peak midluteal values were 546.01 +/- 130.73 ng/mg Cr. Seven of eight became pregnant, indicating that bison exhibit a second seasonal oestrus. Eighteen other bison cows were pregnant prior to the beginning of the study and demonstrated non-cyclic increased PdG concentrations (greater than 200 ng/mg Cr) during the 30-day course of collection. Three cows ovulated and became pregnant during the 30-day collection period and then exhibited increasing urinary PdG concentrations. This report demonstrates that ovarian function in uncaptured bison can be monitored by means of urinary PdG and that both ovulatory cycles and early pregnancy can be detected.

Normal hematological and blood chemistry parameters were measured in 45 American bison (Bison bison) that were divided into three age groups for comparison. There was a statistically significant (P less than 0.05) increase with advancing age in mean corpuscular volume, mean corpuscular hemoglobin, absolute neutrophil and eosinophil counts, total protein, globulin, creatinine, and blood urea nitrogen. There was a statistically significant (P less than 0.05) decrease with advancing age in levels of sorbital dehydrogenase, alkaline phosphatase, glucose, sodium, calcium and phosphorus.