American foulbrood (AFB) is an infectious disease of honey bee brood caused by the endospore-forming bacterium Paenibacillus larvae. P. larvae spores are resilient in the environment, thus colonies with clinical signs of AFB are often destroyed by burning to eradicate the causative agent. To prevent outbreaks of AFB, oxytetracycline metaphylaxis is widely used in North America, resulting in sustained selective pressure for oxytetracycline resistance in P. larvae. To determine if antimicrobial resistance (AMR) is present among P. larvae isolates from commercial beekeeping operations in Saskatchewan, Canada, we performed antimicrobial susceptibility testing of 718 P. larvae samples cultured from pooled, extracted honey collected from 52 beekeepers over a 2-y period, 2019 and 2020. We found that 65 of 718 (9%) P. larvae samples collected from 8 beekeepers were resistant to oxytetracycline with minimum inhibitory concentration (MIC) values of 64-256 µg/mL. Eight of 718 (1%) samples from 4 beekeepers had intermediate resistance to oxytetracycline (MIC: 4-8 µg/mL). Susceptibility testing for tylosin and lincomycin indicated that P. larvae in Saskatchewan continue to be susceptible to these antimicrobials (tylosin MIC: <1 µg/mL, lincomycin MIC: ≤2 µg/mL). Most oxytetracycline-resistant P. larvae samples were identified in northeastern Saskatchewan. Whole-genome sequence analysis identified the P. larvae-specific plasmid pMA67 with tetracycline-resistance gene tet(L) in 9 of 11 oxytetracycline-resistant P. larvae isolates sequenced. Our results highlight the advantage of using pooled, extracted honey as a surveillance tool for monitoring AMR in P. larvae.

Abstract This study evaluated the impact of naturally occurring water with a high-sulfate concentration on dry matter intake (DMI), water intake, growth, and trace mineral status of yearling beef heifers. Angus-based heifers (n = 48; 398.4 ± 22.1 kg) were randomly assigned to 1 of 12 pens (4 heifers/pen) and fed for 100 d arranged into 25 d periods. Heifers were provided water containing 350 (CON); 2,300 (MEDS); or 4,300 mg/L (HIGHS) sulfate. Concentrated water (71,482 mg/L sulfate) from natural source was collected and blended to achieve the treatments. All data were analyzed using the fixed effects of treatment, period (d 1-25, 26-50, 51-75, and 76-100), and the treatment × period interaction, with period as a repeated measure. Average daily gain, and gain-to-feed were not affected (P&amp;gt;0.29). Provision of HIGHS decreased (interaction, P&amp;lt; 0.01) DMI from d 1-25, 26-50 and 51-75, with no effect from d 76-100 compared with CON. Heifers drinking CON and MEDS during d 26-50 had greater (interaction, P&amp;lt; 0.01) water intake than HIGHS with no differences among treatments otherwise. Total sulfate intake (g/d) was greater for HIGHS, followed by MEDS and CON with a greater difference between treatments during d 26-50 (interaction, P&amp;lt; 0.01). Heifers provided MEDS and HIGHS had a greater (interaction, P&amp;lt; 0.01) reduction in serum copper compared with CON. Liver copper concentration did not differ at the start of the study but was 74% and 62% of CON for MEDS and HIGHS, respectively at the end of the study (interaction, P&amp;lt; 0.01). Serum selenium was greater for MEDS and HIGHS than CON; while liver selenium was least for HIGHS heifers at the end of the study (interaction, P&amp;lt; 0.01). These data highlight that beef heifers were able to tolerate 213 g/d of sulfate intake with no negative impact on growth performance; however, MEDS and HIGHS decreased liver copper and liver selenium concentrations.

It is necessary to obtain more recent data on the prevalence and co-occurrence of mycotoxins in feed and food to minimize risks. This study examined the recent presence, co-occurrence, and correlation patterns of six major ergot alkaloids (EAs; i.e. ergocornine, ergocristine, ergocryptine, ergometrine, ergosine, and ergotamine) in cool-season adapted barley (n = 57) and wheat (n = 80) submitted by livestock producers and industries for testing ergot alkaloids/mycotoxins by liquid chromatography − tandem mass spectrometry method. Overall, 91% industry-submitted barley samples and 84% industry-submitted wheat samples tested positive for at least one ergot alkaloid and 33% industry-submitted barley and 38% industry-submitted wheat samples were found to be co-contaminated with all six major EAs. The content of total EAs in 9 industry-submitted barley (16%) and 18 industry-submitted wheat (23%) samples exceeded the recommended maximum allowable level for lactating or pregnant animals (250 ppb). All the barley and wheat samples that contained detectable ergosine were found to co-occur with other EAs. Overall, the content of individual EAs was positively correlated with each other and strong correlations (r > 0.8, P < 0.01) were detected between the content of individual EAs and total EAs. These results implied that the industry and producers submitted cool-season adapted barley and wheat samples contaminated with a single EA is likely to contain high levels of other major EAs. The patterns of individual EAs in this study were distinct from previous studies that focus on samples from European countries. Ergocristine was remained as the predominant EAs in the industry-submitted cool-season adapted barley and wheat samples at levels up to 9438.8 and 12416.2 ppb, respectively. While the mean contents of ergosine were the lowest (68.5 and 50.6 ppb for the industry-submitted cool-season adapted barley and wheat samples, respectively). The high prevalence and co-occurrence of EAs indicated that ergot contamination is still posing a significant threat to food and feed industry and more research is expected to reduce the contamination level and explore the toxicological significance of various co-occurrence profiles. A full scale of investigation for all barley and wheat samples is needed to obtain a full picture of mycotoxin contamination.

Paenibacillus larvae, the causative agent of American foulbrood (AFB), produces spores that may be detectable within honey. We analyzed the spore content of pooled, extracted honey from 52 large-scale (L) and 64 small-scale (S) Saskatchewan beekeepers over a two-year period (2019–2020). Our objectives were: (i) establish reliable prognostic reference ranges for spore concentrations in extracted honey to determine future AFB risk at the apiary level; (ii) identify management practices as targets for mitigation of risk. P. larvae spores were detected in 753 of 1476 samples (51%). Beekeepers were stratified into low (< 2 spores/gram), moderate (2- < 100 spores/gram), and high (≥ 100 spores/gram) risk categories. Of forty-nine L beekeepers sampled in 2019, those that reported AFB in 2020 included 0/26 low, 3/18 moderate, and 3/5 high risk. Of twenty-seven L beekeepers sampled in 2020, those that reported AFB in 2021 included 0/11 low, 2/14 moderate, and 1/2 high risk. Predictive modelling included indoor overwintering of hives, purchase of used equipment, movement of honey-producing colonies between apiaries, beekeeper demographic, and antimicrobial use as risk category predictors. Saskatchewan beekeepers with fewer than 2 spores/gram in extracted honey that avoid high risk activities may be considered at low risk of AFB the following year.

Three commercial honey bee operations in Saskatchewan, Canada, with outbreaks of American foulbrood (AFB) and recent or ongoing metaphylactic antibiotic use were intensively sampled to detect spores of Paenibacillus larvae during the summer of 2019. Here, we compared spore concentrations in different sample types within individual hives, assessed the surrogacy potential of honey collected from honey supers in place of brood chamber honey or adult bees within hives, and evaluated the ability of pooled, extracted honey to predict the degree of spore contamination identified through individual hive testing. Samples of honey and bees from hives within apiaries with a recent, confirmed case of AFB in a single hive (index apiaries) and apiaries without clinical evidence of AFB (unaffected apiaries), as well as pooled, apiary-level honey samples from end-of-season extraction, were collected and cultured to detect and enumerate spores. Only a few hives were heavily contaminated by spores in any given apiary. All operations were different from one another with regard to both the overall degree of spore contamination across apiaries and the distribution of spores between index apiaries and unaffected apiaries. Within operations, individual hive spore concentrations in unaffected apiaries were significantly different from index apiaries in the brood chamber (BC) honey, honey super (HS) honey, and BC bees of one of three operations. Across all operations, BC honey was best for discriminating index apiaries from unaffected apiaries (p = 0.001), followed by HS honey (p = 0.06), and BC bees (p = 0.398). HS honey positively correlated with both BC honey (rs = 0.76, p < 0.0001) and bees (rs = 0.50, p < 0.0001) and may be useful as a surrogate for either. Spore concentrations in pooled, extracted honey seem to have predictive potential for overall spore contamination within each operation and may have prognostic value in assessing the risk of future AFB outbreaks at the apiary (or operation) level.

Baseline data on the boreal jack pine associated chanterelle (Cantharellus cibarius Fr.) and pine mushrooms (Tricholoma magnivelare (Peck) Redhead) in the Boreal Plain Ecozone of Saskatchewan were collected in five ecosites of productive mushroom areas. It investigated hourly weather parameters correlated with daily purchase volumes over 4 yrs; yield data over 5 yrs; and varying age, tree density, and species for presence of mushrooms in over 100 stands. All plots fell within the lichen jack pine (jP) ecosite with an overstory entirely of jack pine. The understory was dominated by reindeer lichen, bearberry, and blueberry. Plots were well- to rapidly drained, subxeric to submesic, with low nutrient regime. Both chanterelle and pine mushrooms were present in jack pine stands of &lt; 20 yrs, with greatest occurrence in pure jack pine stands of 41–60 yrs in moderately open A-B canopy density. Weekly purchase data correlated with environmental parameters. Growing degree days (GDD) (base temperature 5 °C) + soil temperature (minimum 500 ± 70 GDD), + either soil moisture or precipitation (cumulative 50–100 mm) provided the highest regression value with chanterelle yield 6–13 wks prior to first appearance. The 5-yr total chanterelle yield from this region averaged 7100 kg·yr−1. Chanterelle cap diameter was a good predictor of fresh weight and proxy for yield. Pine mushroom was &lt; 10% of chanterelle yield, averaging 1.72 kg·ha−1 over 4 yrs based on 5 days picking. With future climate predictions of warmer and moister conditions, timing of fruiting body appearance is anticipated to advance.

Cicer milkvetch (Astragalus cicer L.) (CMV) is a non-bloating, perennial legume that has shown persistence under grazing. Limited information is available on its seedling establishment and subsequent forage yield and nutritive value in alfalfa (Medicago sativa L.) mixtures. Field plots were seeded in May 2013 at Melfort, SK, Canada, to evaluate ‘Oxley II’ cicer milkvetch performance in ‘AC Grazeland’ alfalfa or alfalfa and ‘AC Success’ hybrid bromegrass (Bromus riparius Rehmann× Bromus inermis Leyss.) mixtures from 2014 to 2017. Two controlled environment tests were also conducted by treating seeds of CMV using alfalfa root aqueous extract. Seed germination and seedling height of CMV were significantly reduced in aqueous extract. In the field, establishment of CMV in a mixture containing alfalfa was reduced, and CMV dry matter proportion in the mixture increased only 3.5% over three years. Increasing CMV seeding rate did not increase its dry matter (DM) percent in the mixtures, indicating a high allelopathic effect of alfalfa. Forage DM yield of all mixtures was linearly correlated to the proportion of alfalfa, and adding hybrid brome did not increase the DM yield. Forage DM yield was higher for the three-cut than the two-cut treatments for CMV–alfalfa mixtures, but there was no difference between the cutting frequency for CMV–alfalfa–hybrid brome mixtures. Fiber concentrations decreased linearly with increased CMV seeding rate in the mixtures. This study showed that CMV establishment in alfalfa mixtures was reduced in a same-row seeding, and the allelopathic effect was not reduced by lower alfalfa seeding rates or adding a grass.

A field experiment with 24 treatments consisting of three perennial forage crops [alfalfa (Medicago sativa L. cv. AC Longview), hybrid bromegrass (Bromus riparius Rehm & Bromus inermis Leyss. cv. AC Success) and their mixture], four Cut 1 dates (approximately June 20, July 10, July 30 or August 20), and two fertilizer levels (unfertilized and fertilized) was established in late May 2014, on a Black Chernozem [Udic Boroll] silty clay soil. Forage dry matter yield [DMY], and concentration (g·kg−1 DM) of crude protein [CP], total digestible nutrients [TDN] and acid detergent fiber [ADF] data were collected over 3 years from 2015 to 2017. The fertilizer treatments were imposed in 2016 and 2017. Forage crops were initially cut at four Cut 1 dates, and again cut [Cut 2] in autumn (September 2 in 2015, November 7 in 2016 and October 5 in 2017). For all three forage crops, forage DMY usually increased when Cut 1 was delayed. Delaying Cut 1 reduced forage DMY for Cut 2. Total DMY (Cut 1 + Cut 2) for all three forage crops was highest from the combination of July 10 and late Autumn cuts. Alfalfa-bromegrass mixture produced higher DMY than bromegrass or alfalfa alone. Fertilizer application resulted in a significant increase in Cut 1 and total DMY for bromegrass. The CP concentration in Cut 1 forage usually declined as the forage crops matured. The CP concentration was highest for alfalfa, followed by alfalfa-bromegrass mixture, and much lower for bromegrass. There was little or no effect of forage crop maturity on the TDN and ADF concentrations in forage. The TDN concentration was higher and ADF concentration was lower in forage from alfalfa or alfalfa-bromegrass mixture than bromegrass. Fertilizer application significantly increased CP concentration for alfalfa-bromegrass mixture. Delaying harvesting for Cut 1 increased ADF yield and TDN yield until Late July, but CP yield generally decreased with crop maturity. The ADF yield and TDN yield were higher for alfalfa-bromegrass mixture than bromegrass or alfalfa alone, and CP yield was similar for alfalfa and alfalfa-bromegrass mixture but considerably higher than bromegrass. Fertilizer application increased CP yield and ADF yield for bromegrass and alfalfa-bromegrass mixture, and TDN yield only for bromegrass. In conclusion, total DMY (Cut 1 + Cut 2) was highest for a combination of Early July and Autumn cuts. Forage yield was highest for alfalfa-bromegrass mixture, followed by alfalfa and lowest for bromegrass. The CP and TDN concentrations were higher, and ADF concentrations were lower in forage from alfalfa or alfalfa-bromegrass mixture than bromegrass.

Synchrotron radiation-based infrared microspectroscopy (SR-IMS) is a nondestructive bioanalytical technique with a high signal-to-noise ratio and high ultraspatial resolution (3-10 μm). It is capable to explore the microstructures of plant tissues in a chemical sense and provide information on the composition, structure, and distribution of chemical compounds/functional groups. The objective of this study was to illustrate how SR-IMS can be used to image the internal microstructures of chickpea seed tissue within a cellular level. Chickpea seeds (CDC Cory) were collected from the Crop Development Center (University of Saskatchewan, Saskatoon, SK). The seeds were frozen at -20 °C on object disks in a cryostatic microtome and then were cut into thin cross sections (ca. 8 μm thick). The experiment was carried out on the mid-infrared beamline (01B1-1) at the Canadian Light Source (Saskatoon, SK). We obtained the ultraspatial images of the chickpea tissue with pixel-sized increments of imaging steps. The results showed that, with the extremely bright synchrotron light, spectra with high signal-to-noise ratios can be obtained from an area as small as 3.3 μm × 3.3 μm, allowing us to observe the seed tissue within a cellular level. Chemical distribution of chickpea such as lipids, protein, and carbohydrates could be mapped, revealing the chemical information of the chickpea internal microstructure. In conclusion, SR-IMS can rapidly characterize the molecular structure of protein, carbohydrates, and lipids at an ultraspatial resolution.

Abstract The authors have withdrawn this preprint due to author disagreement.