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Open Access
Characterizing the gut microbiome of wild-caught and lab-reared larval sea lamprey under different feeding regimes
(2024-08-26) Montalvo-Rodriguez, Patricia Sofia; Docker, Margaret (Biological Sciences); Wang, Feiyue (Environment & Geography); Loseto , Lisa; Good, Sara V.
Lampricide treatments are one of the most common population control methods for invasive larval sea lampreys in the Great Lakes. The success of current population control methods depends on obliterating larval cohorts. However, most testing of the efficacy of different population control methods are carried out on lab-reared larval sea lampreys. In aquaculture, the gut microbiome plays a key role in fitness, including determining how rearing conditions affect the host. This has been studied in many commercially popular fish, but research on the gut microbiome of larval sea lampreys and its role in host growth and development is limited. This is a disadvantage for studies aimed at developing population control methods that depend on lab- reared larvae having a similar physiological response to wild populations of larval sea lampreys. To help breach this research gap, we characterized and compared the gut microbiome of lab- grown (LG), wild-caught lab-reared (WCLR) and wild-caught (WC) larval sea lampreys. Our main findings are that there was a i) strong seasonal pressure driving diversity in the gut microbiome of WC and WCLR larvae; ii) strong influence of the collection site on the gut microbiome of WC larvae; iii) lower diversity of the gut microbiome of LG compared to WC and WCLR samples. Although, we did not detect a core microbiome among our samples, we found common predicted functional pathways among sample types that suggest there could be a microbial functional core. At the genus level, Cetobacterium was the most abundant taxon in WC and WCLR samples. LG samples had unique taxa at higher abundances but shared less abundant taxa with other sample types. Identifying the factors contributing to differences in the microbiome in WCLR or LG samples will inform the development of aquacultural approaches to rearing larval sea lamprey.
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Open Access
The application of C-band and L-band polarimetric microwave radars in cryosphere (terrestrial snowfalls and oil spills within freezing seawater)
(2024-08-26) Zabihi Mayvan, Mahdi; Stern, Gary (Environment and Geography); Ehn, Jens (Environment and Geography); Isleifson, Dustin
The recent global warming and climate change have significantly altered the extents of sea ice and snow. Declining thickness of the Arctic sea ice increases maritime activities for resource extraction, refueling communities, tourism, and shipping. Changes of snowpack threaten water availability for agriculture, drinking water, and hydropower in dependent regions. Thus, remote sensing approach is essential for detecting and monitoring snowfall and oil-contaminated sea ice. This thesis focuses on studying two main objectives: 1) monitoring oil spills within freezing seawater (by aiming to understand the potential impacts of diesel fuel and wind on the growth, thermophysical, and C-band backscattering responses of newly forming sea ice.), and 2) investigating terrestrial snowfall events (by aiming to examine the capabilities of C-band and L-band scatterometers in detecting the presence of dry and wet snow, along with monitoring the thermophysical changes within the snowpacks). In order to investigate the objectives, three experiments were conducted during 2022-23 at the University of Manitoba research facilities (SERF and The Point). The experiments were centered on change detection, dual-frequency, and multi-scenario approaches to provide intercomparable results and interpretations. By accomplishing these objectives, this thesis makes a substantial contribution in developing both contemporary and future C-band and L-band satellites missions. It provides essential data, such as the location and extent of the snow on the ground, as well as the oil-contaminated sea ice in the Arctic for modeling and mapping programs. Consequently, the outcomes will provide successful supports to many climate change counter-responses and strategies around the world.
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Open Access
Participatory Forest Management in Sri Lanka: is it a myth or reality?
(2024-07-16) Batuwatta, Sonali; Sinclair, John (Natural Resources Institute); Nayak, Prateep (Natural Resources Institute); Haque, Emdad
Participatory Forest Management (PFM) has gained attention as a potential solution for sustainable forest conservation and community empowerment. However, its implementation often faces challenges and criticism. This study aims to critically examine the concept of PFM in the context of Sri Lanka, exploring whether it represents a myth or a reality on the ground. Using a secondary qualitative study method including review of literature, published government documents, and community organization reports, in addition to thematic analysis, this research evaluates the genesis of PFM, the role of community in PFM, and ways and means of improving PFM in the Sri Lankan context. The findings reveal the complexities and nuances of PFM implementation in Sri Lanka. While there are instances of successful community involvement and positive outcomes, challenges such as inadequate stakeholder engagement, unequal power dynamics, limited resource allocation, lack of community consultation and engagement, and lack of tenure security persist. The research uncovered inconsistencies between the policies regarding PFM and the practical implementation of these initiatives. This disparity raises questions regarding the efficiency and sustainability of PFM strategies in Sri Lanka. By acknowledging and addressing these challenges, policymakers and stakeholders can work toward enhancing the effectiveness and sustainability of PFM initiatives, ultimately contributing to more resilient and equitable forest ecosystems in Sri Lanka.
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Open Access
Vegetative preferences and the impact of Dutch Elm Disease (Ophiostoma ulmi) on bird abundance in Winnipeg, Manitoba
(2024-09-15) Sawchyn, Jacob; Fraser, Kevin (Biological Sciences); Westwood, Richard (Entomology); Koper, Nicola
Since 2016, Winnipeg’s urban forest has lost more than 33,000 American elm (Ulmus americanus) providing habitat to urban birds due to Dutch Elm Disease (DED) (Ophiostoma ulmi) (Trees Winnipeg, 2021). However, the presence of DED in a migratory and breeding stopover site may increase insect abundance for insectivores and urban bird species, such as resident woodpeckers (spp.), warblers (Parulidae spp.), and other insect-eating birds that forage and nest in dead elm trees (Nicholls, 1994). The research investigates the impact of DED and its potential benefit on bird populations, as well as their vegetative preferences by recording 45 bird abundance point counts conducted across 18 neighbourhoods in Winnipeg during spring migration in 2022 and 2023. Bird abundance and vegetative composition was recorded in 50-m² circular plots next to a focal elm tree on public property that was either healthy, diseased with DED, or sites where elms had been recently removed due to DED to assess the potential positive or negative effects of DED on the bird population’s usage of an urban habitat. Results indicated that year-round residents, as generalists in the urban environment, benefit from DED. However, breeding migrant birds, with their more specialized habitat requirements, are significantly and negatively impacted by DED. The fact that breeding migrants and year-round residents were significantly less abundant in sites where elms had been recently removed underscores the urgent need for effective DED management in Winnipeg to preserve elms as bird habitat. Birds were most abundant near non-native deciduous shrubs, coniferous trees and shrubs, and riparian areas like riverbanks and greenspaces. This highlights the importance of restoring riverbanks, cultivating higher diversity in the urban forest, and increasing connectivity between natural areas in Winnipeg.
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Open Access
Isotopic and petrologic constraints on intracontinental deformation and metamorphism, Churchill Province, Nunavut
(2024-08-27) Drayson, Derek; Bohm, Christian (Earth Sciences); Oliver, Derek (Electrical and Computer Engineering); Gibson, Dan (Simon Fraser University); Pehrsson, Sally (Geological Survey of Canada); Camacho, Alfredo; Anderson, Scott
The Canadian Churchill Province was the locus of repeated, regional reworking in the Paleoproterozoic associated with five major orogenic events that ultimately resulted in the formation of Earth’s first supercontinent, Nuna. Tectonic models for the Archean and Paleoproterozoic evolution of the Churchill Province have been formulated at the broadest scale, and consequently, the timing, nature and regional extent of deformation and metamorphism associated with these collisional events are poorly constrained. In this thesis, the metamorphic and deformation histories of two relatively unexplored regions in Nunavut were characterized in order to contribute to the understanding of the processes that reworked the boundaries and interior of the Churchill Province during development of Nuna. Aeromagnetic data and geological mapping on Boothia Peninsula, Nunavut, revealed the presence of a ~165 km long, 5-10 km wide high-strain zone, named the Sanagak Lake shear zone (SLsz), that marks the transition from dominantly N-trending Thelon-related structures in the north to SW-trending Trans-Hudson-related structures in the south. Field, microstructural, petrologic and isotopic data indicated that the SLsz is a south-dipping, strike-slip (sinistral) shear zone that formed in the mid-crust (~ 0.52 GPa) at 1804 ± 6 Ma. The timing, geometry and kinematics of high-strain deformation is consistent with north-directed compression associated with far-field stresses derived from the Trans-Hudson orogeny, and marks the northern limit of Trans-Hudson related deformation. Geologic mapping, phase equilibria modelling, and multi-mineral geochronology coupled with previously collected petrological and isotopic data from the Baker Lake area outline four lithotectonic domains named the Woodburn Lake and Ketyet River groups, Quoich River domain, Kramanituar Complex and the Thirty Mile domain. Each of these domains experienced distinct pressure – temperature – time – deformation (P-T-t-d) histories and are separated by shear zones that facilitated differential burial-exhumation in the Paleoproterozoic. All domains were buried and reworked, to varying degrees, between ca. 1.93 and 1.90 Ga during the Snowbird Orogeny. The Kramanituar Complex was exhumed rapidly following ca. 1.9 Ga metamorphism, whereas the Quoich River and Thirty Mile domains exhumed between ca. 1.87 and 1.85 Ga during the accretionary phases of the Trans-Hudson Orogeny.
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Open Access
Crude protein content and probiotic supplementation in sows: effects on sow and piglet performance and indices of gut health
(2024-08-27) Chrapun, Leah; Yang, Chengbo (Animal Science); Rogiewicz, Anna (Animal Science); Nyachoti, Martin
Since the use of in-feed antibiotics has been banned in many jurisdictions, alternative methods that maintain animal performance and health are being investigated. The objective of this study was to investigate the effects of crude protein (CP) content and supplementation of Bacillus-based probiotics (PRO) in late-gestation and lactation sow diets on performance of sows and gut health of suckling pigs. A total of 120 pregnant sows (60 gilts and 60 2+ parity) were assigned to one of four dietary treatments in a 2 x 2 factorial arrangement (2 CP levels, with or without PRO supplementation) from d 85 of gestation to d 21 of lactation. The experiment was conducted in 4 consecutive periods (half gilts and half sows per period). The diets consisted of 1) a corn-soybean meal (SBM)-based low CP (LCP; 12% CP) diet; 2) LCP + 0.05% probiotic (LCP-PRO); 3) a corn-SBM-based high CP (HCP; 15% CP) diet; and 4) HCP + 0.05% probiotic (HCP-PRO) and were formulated in 2 phases: gestation (d 85 – 115) and lactation (d 0 – 21). Commercially swine diets often contain approximately15% CP, therefore the HCP diet in this study reflects the industry standard. Lactation diets contained 14% and 17% CP for LCP and HCP respectively. Sow body weight (BW) and backfat (BF) thickness were recorded on d 85 and 111 of gestation and on d 1 and 21 of lactation. Sow blood and milk were sampled on d 1 and 17 of lactation to analyze plasma urea nitrogen (PUN) concentration, and milk fat, protein, and lactose, respectively. Reproductive performance data were recorded on d 0 of lactation and sow feces were collected d 12 of lactation for digestibility and microbial analysis. One piglet per sow close to average BW for each litter was selected for blood collection to analyze PUN and fecal collection for microbial analysis. Data were analyzed using the PROC MIXED of SAS. The statistical model included CP, PRO and their interaction as fixed effects, and period and replication as random effects. There was an interaction (P < 0.05) between CP and PRO on the number of stillbirths, where the number of stillbirths did not differ between LCP and LCP-PRO groups, while the number decreased in sows fed the HCP-PRO diet compared with the HCP diet. Sows fed LCP diets had reduced (P < 0.05) PUN concentrations on d 1 and d 17 of lactation compared with those fed HCP diets. No difference was found in fat, protein, or lactose content in both colostrum (d 1) and milk (d 17). Piglets from the sows fed LCP diets showed heavier (P < 0.05) birth weights (1.58, 1.57, 1.53, and 1.52 kg for diets 1 to 4) than those in HCP groups, however, the average daily gain (ADG) of week 1 (188, 166, 187, and 187 g for diets 1 to 4) was lower (P < 0.05) for piglets in LCP groups than HCP groups. There was an interaction (P < 0.05) between CP and PRO on piglet fecal DM, where HCP-PRO had higher fecal DM percentage than HCP, however, LCP and LCP-PRO groups did not differ. There was an interaction of CP and PRO on d 21 relative abundance of E. coli, where the abundance of was lower (P < 0.05) in piglets from sows fed HCP-PRO diets compared to piglets from sows fed HCP diets, however, piglets from sows fed LCP diet had a lower abundance (P < 0.05) of E.coli than piglets from sows receiving LCP-PRO diets. There was an interaction effect of CP and PRO on the relative abundance of Lactobacillus in piglets at age 21. Piglets from sows receiving HCP diets had a lower (P < 0.05) relative abundance compared to piglets from sows receiving HCP-PRO diets. Conversely, piglets from sows fed LCP-PRO diets had a lower (P < 0.05) relative abundance of Lactobacillus compared to piglets from sows fed LCP diets. On d 28, piglets from sows fed LCP diets had a decreased (P < 0.05) relative abundance of E.coli compared to pigs from sows fed HCP diets. There was an interaction effect of CP and PRO on d 28 where piglets from sows fed HCP diets had a decreased (P < 0.05) relative abundance of Clostridium perfringens compared to those from sows fed HCP-PRO diets. In conclusion, feeding LCP diets supplemented with PRO to sows has the potential to improve both the reproductive performance of sows and the gut health of suckling pigs.
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Open Access
Effects of polysaccharide iron complexes on growth, gut health, and gut microbiota in nursery pigs raised under different sanitary conditions
(2024-08-27) Cai, Zhen; Nyachoti, Martin (Animal Science); O, Karmin (Animal Science); Yang, Chengbo
This study evaluated the effect of different iron sources, including iron polysaccharide complexes (SQM®.iron) and ferrous sulfate (FS) on growth performance, gut health, pathogenic bacteria load, colon microbiota, and fecal iron concentration in nursery pigs. A total of 320 weaned pigs were randomly assigned to four treatments arranged in a 2 × 2 factorial design, with the factors being sanitation conditions (clean vs. dirty) and iron sources (SQM® iron vs. FS, each at 100 mg iron/kg) to give 8 pens (10 piglets per pen) per treatment. Pigs were fed their respective diets in two phases over a 28-d period. Fecal scores, body weight (BW), and feed intake were recorded weekly. Iron content, gene expression of butyryl-CoA:acetate CoA-transferase and bisulfite reductase, and pathogenic bacteria quantification were determined in fresh fecal samples collected on d 0, d 14, and d 21. On d 28, one pig randomly selected from each pen was euthanized to sample colon digesta for 16S rRNA analysis and sample jejunal tissue and serum for gut integrity and permeability analysis. Overall, SQM® iron resulted in higher average daily gain (ADG) from d 0 to14 and average daily feed intake (ADFI) from d 0 to 28 (P < 0.05). SQM® iron resulted in higher fecal iron at d 21 and improved fecal scores at d 27 (P < 0.05). Dietary iron treatments did not significantly affect gastrointestinal integrity and permeability in jejunum and did not alter fecal microbiota composition on d 28. In conclusion, substituting 100 mg/kg added iron as ferrous sulfate with equal concentration of SQM® iron improved ADG in the phase 1 (d 0 to 14) and overall ADFI (d 0 to 28) in weaned pigs.
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Open Access
Impact of bread waste inclusion in feedlot diets on the environmental footprint of growing and finishing beef cattle
(2024-08-27) Hansen, Janine; McAllister, Tim (Animal Science); Stanford, Kim (Animal Science); Terry, Stephanie (Animal Science); Cordeiro, Marcos (Animal Science); Ominski, Kim
The objective of this research was to examine the impact of including bread waste in feedlot diets on the environmental footprint of beef cattle. Existing data including diet composition and animal performance metrics (body weight, average daily gain, dry matter intake, feed:gain ratio) were obtained from two previous feeding trials in which steers were fed bread by-product (BBy) at rates of 40% (growing steers) and 55% DM (finishing steers). Environmental footprint metrics were estimated through modeling approaches and included land use requirements, greenhouse gas (GHG) emissions, ammonia (NH3) emissions, and water use requirements. Including bread waste in the diets of growing steers resulted in a 45% decrease in land use (ha hd-1) for feed crops, a 14% decrease in GHG emission intensity (kg CO2e hd-1), a 4% decrease in NH3 emission intensity (kg NH3 hd-1), and a 37% decrease in water use intensity (L kg-1 live weight) compared to steers fed a conventional corn-based diet. Finishing steers fed a BBy-based diet had a 63% reduction in land use (ha hd-1) for feed production, a 19% reduction in GHG emission intensity (kg CO2e hd-1), 1% reduction in NH3 emissions (kg NH3 hd-1), and a 61% reduction in water use intensity (L kg-1 live weight). Furthermore, GHG emissions associated with BBy from production to waste management were 24% and 53% lower when diverting BBy from landfill to growing and finishing diets, respectively. Utilizing bread waste in feedlot diets not only reduces the environmental footprint of growing and finishing cattle but makes use of land, water and fertilizer resources that have already been expended. Furthermore, as bread waste is priced lower than conventional feedstuffs, its inclusion in feedlot diets is expected to reduce the cost of production for growing and finishing cattle. Despite the benefits, current challenges that must be considered include availability and proximity of bread waste to feedlots, short shelf life, and regulatory restrictions.
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Open Access
Connecting farmer well-being with cattle health and perceptions of wildlife on dairy and beef farms in Western Canada and Ontario
(2024-08-26) Zwick, Breanna; Ominski, Kim (Animal Science); Pajor, Ed (Animal Science); Campbell, Michael (Environment and Geography); King, Meagan
This study surveyed 88 dairy and 17 beef farmers in Western Canada and Ontario to assess farmer well-being, and how it is connected to cattle health and perceptions of wildlife. Well-being was assessed using validated psychometric scales for mental health, sleep and injuries for physical health, and questions about social well-being. The survey additionally assessed farm management, animal health (including mastitis, and calf mortality), and perceptions and management of wildlife. Dairy farm visits (n=66) were conducted to assess lameness, body condition, and knee, neck, and hock lesions on a representative sample of each herd’s lactating cows (30% to a maximum of 69 cows). Dairy farmer responses were analyzed statistically, and beef farmer data are presented using descriptive statistics due to a low response rate. For dairy farmers, clinical lameness tended to be negatively associated with stress scores (P=0.07) and anxiety scores (P=0.06), and mastitis incidence was positively associated with stress scores (P=0.02). Beef farmers reported stress related to weather, pasture condition, and finances, but were generally satisfied with their personal relationships at home. Associations between beef farmers’ well-being and cattle health could not be drawn in this study. Overall, there was a connection between farmer well-being and animal health on dairy farms, but more research is needed to determine the factors that influence these associations. Regarding wildlife perceptions, both dairy and beef farmers viewed mice and rats, raccoons, and corvids negatively. Beef farmers additionally had negative perceptions of small mammals and large predatory mammals. Dairy farmers with negative perceptions of mice tended to have higher depression scores (P=0.0002), as well as lower resilience scores (P=0.07), even when considering region. The majority of dairy and beef farmers reported using wildlife control for mice, raccoons, and corvids and reported choosing these methods based on effectiveness, ease of use, and cost.
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Open Access
Using quantitative methods to understand how dairy farmer wellbeing connects to farm management, barn design, technology, and animal welfare
(2024-08-27) Tambadou, Halimatou; Plaizier, Kees (Animal Science); Hagen, Briana (Animal Sciene); Winder, Charlotte (Animal Science); King, Meagan
The agricultural profession, particularly dairy farming, is known for its demanding nature, both physically and mentally. Dairy farmers encounter various challenges including long working hours, physical labour, financial pressures, and unpredictable weather conditions. My objective was to explore different farm management practices, farming factors, and the prevalence of mental and physical health issues among dairy farmers in Western Canada and Ontario. Statistical analyses included t-tests, ANOVA, and chi-squared tests to compare means with general population averages and to investigate associations between mental health scores and physical health outcomes with survey variables. The results of the survey indicated that farmers (n=115) scored significantly higher on perceived stress (P<0.001), anxiety (P<0.001), depression (P=0.04), and resilience scales (P<0.001) compared to the general population. The results also highlighted concerns regarding the physical health of dairy farmers, with the majority reporting work-related injuries and health issues. I identified significant differences when comparing mental and physical health with work-life balance, social environment and support, and specific dairy-related stressors. Farmers faced both personal and farming-related financial stressors. Surprisingly, health outcomes did not differ based on housing or milking system, management practices, farm responsibilities, or financial and transition planning variables. Therefore, dairy farmers appear to have similar well-being in different production systems, but farm finance, feed cost, weather, and workload constraints are major stressors. I then adopted a more holistic approach to cluster farmers based on their well-being and farm management. The analysis identified four distinct groups of dairy farmers based on their survey responses. It also emphasized the need for a deeper understanding of the unique challenges faced by individual farmers in their production systems. Without this understanding, there is a risk of developing intervention plans that are ineffective or inappropriate for the Canadian dairy industry. The typologies developed in this research offer a promising foundation for providing tailored support resources.