The Sustainability of Bison Production in North America: A Scoping Review

Evaluating Two Sampling Methods for Mycoplasma Bovis Diagnosis in American Bison (Bison bison)

Mycoplasma bovis is a bacterial pathogen endemic to cattle. In the early 2000s, M. bovis emerged as a cause of respiratory disease in American bison (Bison bison), causing significant morbidity and mortality. Bison herds that experience an outbreak of M. bovis are at higher risk for subsequent outbreaks, suggesting that chronic, subclinical infections can be established. Antemortem testing is therefore crucial to disease management; however, the precise sampling method to maximize detection of M. bovis in bison is unknown. We evaluated two sample types-superficial nasal swabs and deep nasopharyngeal swabs-collected from apparently healthy or symptomatic bison from January 2021 through December 2022. We used real-time PCR to detect M. bovis in 76/938 bison (8.1%) from 11 herds. For bison testing positive on at least one swab type, M. bovis was detected in 63/76 (82.8%) deep nasopharyngeal swabs and 29/73 (38.1%) superficial nasal swabs. Agreement between swabs for positive bison was 21% (n=16, kappa coefficient 0.319). We conclude that deep nasopharyngeal swabbing is more sensitive than superficial nasal swabbing for detection of M. bovis in bison and that low agreement between methods may be related to stage of infection. We further tested pooled samples by PCR and found that pooling of up to five samples can be effective to increase throughput and minimize costs. Management of wild bison relies on the ability to relocate animals to maintain gene flow and healthy populations. Sensitive and specific diagnostic tests are needed to inform decisions and minimize risk of transmission, especially from subclinical carriers. This study provides valuable insight that will inform best practices for M. bovis testing, thereby supporting the conservation of bison as healthy wildlife, which in turn promotes ecological restoration, safeguards cultural practices of Tribal Nations, and upholds the bison as a unique American icon.

Benchmarking the United States bison meat industry: stakeholder perceptions, production parameters, and live animal factors affecting meat quality

The objectives of this study were 1) to understand stakeholder perceptions regarding the bison industry, 2) to benchmark live animal characteristics and production parameters of the bison industry, and 3) to identify live animal factors related to animal welfare and their effect on specific quality characteristics of bison meat. A survey was conducted both online and in-person at the National Bison Association Winter Conference (2022). Descriptive statistics were performed on a total of 110 surveys. Most stakeholders (94%, n = 104) agreed that the industry should continue to grow, and the majority (99%, 108) agreed that animal welfare impacts meat quality. Facility design (80%, n = 88), animal handling (78%, 86), employee training (56%, 62), and transportation duration (56%, 62) were selected as the factors that affect animal welfare. More than half of the stakeholders selected flavor (67%, n = 74) as the most important quality attribute of bison meat. For the in-plant antemortem and postmortem parameters data was collected from three plants in the United States over the course of a year. A total of 2,284 bison (bulls: n = 1,101; cows: n = 199; heifers: n = 984) were included in the study. Antemortem measurements such as distance traveled, vocalization, prod use, mobility, and head bumps were measured, followed by postmortem measurements that included bruise score, live weight, dressing percentage, ribeye area, and instrumental color. Approximately 97% of bison (n = 2,213) had at least one bruise. The average distance traveled from producer to slaughter plant was (mean ± SD; 823 ± 583 km) and the average dressing percentage was (mean ± SD; 60.5 ± 3.3%). Average (mean ± SD) fat thickness and ribeye area were 1.4 ± 1.1 cm and 62.6 ± 9.8 cm2, respectively. Approximately 30% (n = 676) of the bison in this study head bumped between 1 and 5 times in the restraining chute or the single-file gate before being stunned. Linear regression indicated that differences in lean a* were associated with plant, number of head bumps in the chute, ribeye area, fat thickness, live weight, and sex class (P < 0.05). Logistic regression indicated that season, sex class, live weight, plant, and season were associated with differences (P < 0.05) in bruising. These results can be used as a baseline for current production parameters and serve as the foundation for future research to monitor improvement.