Animal & Range Sciences
Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/9
The curricula in animal science provide students with a firm foundation in the biological and natural sciences, animal breeding, reproductive physiology, nutrition, and livestock production and management. Natural Resources & Rangeland Ecology focuses on managing the interaction of livestock, and wildlife and their rangeland habitats. Emphasis is placed on soil, water and vegetation attributes which influence habitat ecology and management of livestock and wildlife.
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Item Perceived Stress and Molecular-BV in the NIH Longitudinal Study of Vaginal Flora(Oxford University Press, 2021-05) Turpin, Rodman; Slopen, Natalie; Borgogna, Joanna C.; Yeoman, Carl J.; He, Xin; Miller, Ryan S.; Klebanoff, Mark A.; Ravel, Jacques; Brotman, Rebecca M.Vaginal microbiota provide the first line of defense against urogenital infections primarily through protective actions of Lactobacillus spp. Perceived stress increases susceptibility to infection through several mechanisms, including suppression of immune function. We investigated if stress was associated with deleterious changes to vaginal bacterial composition in a subsample of 572 women in the Longitudinal Study of Vaginal Flora, sampled from 1999 through 2002. Using Cox proportional-hazard models, both unadjusted and adjusted for sociodemographics and sexual behaviors, participants who exhibited a 5 unit-increase in Cohen’s perceived stress scale had greater risk (aHR=1.40, 95% CI 1.13-1.74) of developing molecular bacterial vaginosis (BV), a state with low Lactobacillus abundance and diverse anaerobic bacteria. A 5-unit stress increase was also associated with greater risks for transitioning from the L. iners-dominated community state type (26% higher) to molecular-BV (aHR=1.26, 95% CI 1.01-1.56) or maintaining molecular-BV from baseline (aHR=1.23, 95% CI 1.01-1.47). Inversely, women with baseline molecular-BV reporting a 5-unit stress increase were less likely to transition to microbiota dominated by L. crispatus, L. gasseri, or L. jensenii (aHR=0.81, 95% CI 0.68-0.99). These findings suggest psychosocial stress is associated with vaginal microbiota composition, inviting a more mechanistic exploration of the relationship between psychosocial stress and molecular-BV.Item Biogenic Amines Increase the Odds of Bacterial Vaginosis and Affect the Growth of and Lactic Acid Production by Vaginal Lactobacillus spp.(American Society for Microbiology, 2021-04) Borgogna, Joanna-Lynn C.; Shardell, Michelle D.; Grace, Savannah G.; Santori, Elisa K.; Americus, Benjamin; Li, Zhong; Ulanov, Alexander; Forney, Larry; Nelson, Tiffanie M.; Brotman, Rebecca M.; Ravel, Jacques; Yeoman, Carl J.Bacterial vaginosis (BV) is the most common vaginal disorder of reproductive-aged women, yet its etiology remains enigmatic. One clinical symptom of BV, malodor, is linked to the microbial production of biogenic amines (BA). Using targeted liquid chromatography mass spectrometry, we analyzed 149 longitudinally collected vaginal samples to determine the in vivo concentrations of the most common BAs and then assessed their relationship to BV and effect upon the growth kinetics of axenically cultured vaginal Lactobacillus species. Increases in cadaverine, putrescine, and tyramine were associated with greater odds of women transitioning from L. crispatus-dominated vaginal microbiota to microbiota that have a paucity of Lactobacillus spp. and from Nugent scores of 0 to 3 to Nugent scores of 7 to 10, consistent with BV. Exposure to putrescine lengthened the lag time and/or slowed the growth of all vaginal Lactobacillus spp. except L. jensenii 62G. L. iners AB107’s lag time was lengthened by cadaverine but reduced in the presence of spermidine and spermine. The growth rate of L. crispatus VPI 3199 was slowed by cadaverine and tyramine, and strain-specific responses to spermine and spermidine were observed. BAs were associated with reduced production of d- and l-lactic acid by vaginal Lactobacillus spp., and this effect was independent of their effect upon Lactobacillus species growth. The exceptions were higher levels of d- and l-lactic acid by two strains of L. crispatus when grown in the presence of spermine. Results of this study provide evidence of a direct impact of common biogenic amines on vaginal Lactobacillus spp.Item Relationships among intramammary health, udder and teat characteristics, and productivity of extensively managed ewes(Oxford University Press, 2021-02) Knuth, Ryan M.; Stewart, Whit C.; Taylor, Joshua B.; Bisha, Bledar; Yeoman, Carl J.; Van Emon, Megan L.; Murphy, Thomas W.Mastitis is an economically important disease and its subclinical state is difficult to diagnose, which makes mitigation more challenging. The objectives of this study were to screen clinically healthy ewes in order to 1) identify cultivable microbial species in milk, 2) evaluate somatic cell count (SCC) thresholds associated with intramammary infection, and 3) estimate relationships between udder and teat morphometric traits, SCC, and ewe productivity. Milk was collected from two flocks in early (<5 d) and peak (30 to 45 d) lactation to quantify SCC (n = 530) and numerate cultivable microbial species by culture-based isolation followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS; n = 243) identification. Within flock and lactation stage, 11% to 74% (mean = 36%) of samples were culture positive. More than 50 unique identifications were classified by MALDI-TOF MS analysis, and Bacillus licheniformis (18% to 27%), Micrococcus flavus (25%), Bacillus amyloliquefaciens (7% to 18%), and Staphylococcus epidermidis (26%) were among the most common within flock and across lactation stage. Optimum SCC thresholds to identify culture-positive samples ranged from 175 × 103 to 1,675 × 103 cells/mL. Ewe productivity was assessed as total 120-d adjusted litter weight (LW120) and analyzed within flock with breed, parity, year, and the linear covariate of log10 SCC (LSCC) at early or peak lactation. Although dependent on lactation stage and year, each 1-unit increase in LSCC (e.g., an increase in SCC from 100 × 103 to 1,000 × 103 cells/mL) was predicted to decrease LW120 between 9.5 and 16.1 kg when significant. Udder and teat traits included udder circumference, teat length, teat placement, and degree of separation of the udder halves. Correlations between traits were generally low to moderate within and across lactation stage and most were not consistently predictive of ewe LSCC. Overall, the frequencies of bacteria-positive milk samples indicated that subclinical mastitis (SCM) is common in these flocks and can impact ewe productivity. Therefore, future research is warranted to investigate pathways and timing of microbial invasion, genomic regions associated with susceptibility, and husbandry to mitigate the impact of SCM in extensively managed ewes.Item In Vivo Competitions between Fibrobacter succinogenes, Ruminococcus flavefaciens, and Ruminoccus albus in a Gnotobiotic Sheep Model Revealed by Multi-Omic Analyses(American Society for Microbiology, 2021-04) Yeoman, Carl J.; Fields, Christopher J.; Lepercq, Pascale; Ruiz, Philippe; Forano, Evelyne; White, Bryan A.; Mosoni, PascaleRuminant animals, including cattle and sheep, depend on their rumen microbiota to digest plant biomass and convert it into absorbable energy. Considering that the extent of meat and milk production depends on the efficiency of the microbiota to deconstruct plant cell walls, the functionality of predominant rumen cellulolytic bacteria, Fibrobacter succinogenes , Ruminococcus albus , and Ruminococcus flavefaciens , has been extensively studied in vitro to obtain a better knowledge of how they operate to hydrolyze polysaccharides and ultimately find ways to enhance animal production.Item Dryland Cropping Systems, Weed Communities, and Disease Status Modulate the Effect of Climate Conditions on Wheat Soil Bacterial Communities(2020-08) Ishaq, Suzanne L.; Seipel, Tim F.; Yeoman, Carl J.; Menalled, Fabian D.Little knowledge exists on how soil bacteria in agricultural settings are impacted by management practices and environmental conditions in current and predicted climate scenarios. We assessed the impact of soil moisture, soil temperature, weed communities, and disease status on soil bacterial communities in three cropping systems: (i) conventional no-till (CNT) systems utilizing synthetic pesticides and herbicides, (ii) USDA-certified tilled organic (OT) systems, and (iii) USDA-certified organic systems with sheep grazing (OG). Sampling date within the growing season and associated soil temperature and moisture exerted the greatest effect on bacterial communities, followed by cropping system, Wheat streak mosaic virus (WSMV) infection status, and weed community. Soil temperature was negatively correlated with bacterial richness and evenness, while soil moisture was positively correlated with bacterial richness and evenness. Soil temperature and soil moisture independently altered soil bacterial community similarity between treatments. Inoculation of wheat with WSMV altered the associated soil bacteria, and there were interactions between disease status and cropping system, sampling date, and climate conditions, indicating the effect of multiple stressors on bacterial communities in soil. In May and July, cropping system altered the effect of climate change on the bacterial community composition in hotter conditions and in hotter and drier conditions compared to ambient conditions, in samples not treated with WSMV. Overall, this study indicates that predicted climate modifications as well as biological stressors play a fundamental role in the impact of cropping systems on soil bacterial communities.