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Effect of anaerobic digestate fuel pellet production on Enterobacteriaceae and Salmonella persistence
Get PDFPublication history: Accepted - 10 June 2022; Published online - 7 July 2022.Production of digestate pellets for fuel has been identified as a promising circular
economy approach to provide renewable energy and additional income to
farms, while at the same time presenting the potential to divert raw digestate
from nutrient-saturated
land and reduce the risk to water quality. Although
previous research has investigated the feasibility of pellet production, there
has been little focus on the bio-safety
aspects of the system. Little is currently
known about the persistence of bacteria present in the digestate and the potential
impacts on human health for those handling this product. The aim of
the present research was to determine the effect that each step in the pellet
production process has on bacteria numbers: anaerobic digestion, mechanical
separation, solid drying, and pelletisation. Enterobacteriaceae enumeration
by colony count method was used to quantify bacteria, and the presence of
Salmonella at each stage was determined. The Enterobacteriaceae count reduced
with each stage, and the final pelletisation step reduced bacteria numbers
to below detectable levels (<10 colony forming units/g). Salmonella was
only detected in the starting slurry and absent from digestate onwards. Storage
of the pellets under winter and simulated summer conditions showed no reactivation
of Enterobacteriaceae over time. The pelletisation process produces a
digestate product with Enterobacteriaceae counts below the maximum threshold
(PAS110 specification) for transport off the source farm, but care must still
be taken when handling digestate pellets as complete sterilisation has not been
confirmed.This project was supported by The Bryden Centre. The
Bryden Centre project is supported by the European
Union's INTERREG VA Programme, managed by the
Special EU Programmes Body (SEUPB).
The work was also supported
by Queen's University Belfast and the Agri-Food
and Biosciences Institute in Northern Ireland
European badger (Meles meles) responses to low-intensity, selective culling: using mark recapture and relatedness data to assess social perturbation
Get PDFPublication history: Accepted - 20 June 2022; Published online - 28 July 2022Culling the main wildlife host of bovine tuberculosis in Great Britain (GB) and Ireland, the European badger (Meles meles), has been employed in both territories to reduce infections in cattle. In GB, this has been controversial, with results suggesting that culling induces disturbance to badger social structure, facilitating wider disease dissemination. Previous analyses hypothesized that even very low-level, selective culling may cause similar deleterious effects by increasing ranging of individuals and greater mixing between social groups.
To assess this hypothesis, a novel, prospective, landscape-scale ‘before-and-after’ Test and Vaccinate or Remove (TVR) study was implemented. Test-positive badgers were culled and test-negative badgers were Bacillus Calmette–Guérin (BCG) vaccinated and released.
Mark–recapture metrics of badger ranging and genetic metrics of social group relatedness did not change significantly over the study period. However, selective culling was associated with a localized reduction in social group relatedness in culled groups.
Ecological context is important; extrapolation across territories and other disease epidemiological systems (epi-systems) is likely to be challenging. However, we demonstrate that small-scale, selective removal of test-positive badgers was not associated with metrics of increased ranging but was associated with localized changes in social group relatedness. This adds to the evidence base on badger control options for policy makers.Department of Agriculture, Environment and Rural Affairs (DAERA) N
Identification of high-value bioactive constituents in Northern European willow varieties: S.X. Dasyclados, Endeavour, Cheviot, Tora, Resolution, S. Purpurea, Terranova, endurance
Get PDFPublication history: Accepted - 2 September 2022; Published online - 5 September 2022Willow trees have maintained their place in medicine for many years as they are herbal source of various cures. Willow varieties are considered to contain a wide range of anti-inflammatory and anti-bacterial species such as salicylates and flavonoids. The current work is centred on the presence of high bioactive pharmaceutical constituents other than salicin such as flavan-3-ol catechin, salicortin, and other complex compounds, which contribute to the total medical value of willow extracts. To evaluate the distribution of these bioactives, bark, and wood fractions of 8 different willow varieties (S.X. Dasyclados, Endeavour, Cheviot, Tora, Resolution, S. Purpurea, Terranova, Endurance) were extracted using dispersive solid phase extraction and then analysed using LC-MS comprising a quadrupole time-of-flight spectrometer. Indeed, various high value constituents such as salicortin, catechin, triandrin, acacetin-5-O-xyloside, picein, apigenin-7-O-glucoside, vitexin-2-rhamnoside, luteolin-7-glucoside, catechin gallate, and kaempferol as well as giberellic and 5-methoxysalicylic acid were detected in bark and wood fractions of the willow varieties 80:20 ethanol/water extracts.This work was supported by the Interreg NWE BioWILL project NWE964
Synthetic and biological surfactant effects on freshwater biofilm community composition and metabolic activity
Get PDFPublication history: Accepted - 8 September 2022; Published - 19 September 2022.Surfactants are used to control microbial biofilms in industrial and medical settings. Their known toxicity on aquatic biota,
and their longevity in the environment, has encouraged research on biodegradable alternatives such as rhamnolipids. While
previous research has investigated the effects of biological surfactants on single species biofilms, there remains a lack of
information regarding the effects of synthetic and biological surfactants in freshwater ecosystems. We conducted a mesocosm
experiment to test how the surfactant sodium dodecyl sulfate (SDS) and the biological surfactant rhamnolipid altered
community composition and metabolic activity of freshwater biofilms. Biofilms were cultured in the flumes using lake water
from Lake Lunz in Austria, under high (300 ppm) and low (150 ppm) concentrations of either surfactant over a four-week
period. Our results show that both surfactants significantly affected microbial diversity. Up to 36% of microbial operational
taxonomic units were lost after surfactant exposure. Rhamnolipid exposure also increased the production of the extracellular
enzymes, leucine aminopeptidase, and glucosidase, while SDS exposure reduced leucine aminopeptidase and glucosidase.
This study demonstrates that exposure of freshwater biofilms to chemical and biological surfactants caused a reduction of
microbial diversity and changes in biofilm metabolism, exemplified by shifts in extracellular enzyme activities.SG is funded by an Ulster University Vice Chancellors Doctoral
Research Fellowship, and received additional support through
an Ulster University Broadening Horizons Travel Bursary. Analytical
costs were partly supported by the HYDRO-DIVERSITY project
funded by the Environmental Systems Sciences Program of the Austrian
Academy of Sciences (ÖAW) to JS, and core funding of the AFBI
Aquatic Chemistry Laboratory (WH)
The Mayfly Baetis atlanticus (Soldán & Godunko, 2006) (Ephemeroptera: Baetidae) recorded in the Upper Bann catchment, Northern Ireland
Get PDFPublication history: Accepted - 4 August 2021; Published online - 28 January 202
Evidence of Long-Distance Coastal Sea Migration of Atlantic Salmon, Salmo Salar, Smolts from Northwest England (River Derwent).
Get PDFPublication history: Accepted - 10 January 2022; Published online - 26 January 2022Background
Combining data from multiple acoustic telemetry studies has revealed that west coast England Atlantic salmon (Salmo salar L.) smolts used a northward migration pathway through the Irish Sea to reach their feeding grounds. Hundred Atlantic salmon smolts were captured and tagged in May 2020 in the River Derwent, northwest England as part of an Environment Agency/Natural England funded project.
Results
Three tagged smolts were detected on marine acoustic receivers distributed across two separate arrays from different projects in the Irish Sea. One fish had migrated approximately 262 km in 10 days from the river mouth at Workington Harbour, Cumbria to the northernmost receiver array operated by the SeaMonitor project; this is the longest tracked marine migration of an Atlantic salmon smolt migrating from the United Kingdom. This migrating fish displayed behaviours which resulted in fast northward migration. The remaining two fish were detected on a receiver array operated by a third project: the Collaborative Oceanography and Monitoring for Protected Areas and Species (COMPASS).
Conclusion
These detections further provide evidence that migration to reach marine feeding grounds of at least a proportion of salmon smolts from rivers draining into the Irish Sea is northerly, though without a southern marine array it is impossible to conclude that this is the only route. The pattern of these detections would not have been possible without the collaborative efforts of three distinct and separately funded projects to share data. Further work is required to fully understand migration trajectories in this species on the west coast of the British Isles.The main Funding bodies for this project were the Environment Agency, Cumbria and Natural England, Cumbria. Additional funding was provided by The Derwent Owners Association and Bowland Game: Isel Fishings
Can metrics of acceleration provide accurate estimates of energy costs of locomotion on uneven terrain? Using domestic sheep (Ovis aries) as an example
Get PDFPublication history: Accepted - 18 February 2022; Published - 3 March 2022.Background: Locomotion is often a necessity for animal survival and can account for a large proportion of an individual’s
energy budget. Therefore, determining the energy costs of locomotion is an important part of understanding
the interaction between an animal and its environment. Measures of animal acceleration, specifically ‘dynamic body
acceleration’ (DBA) has proved to be a useful proxy of the energy cost of locomotion. However, few studies have
considered the effects of interacting factors such as the animal’s speed or changes to the terrain slope on the putative
acceleration versus energy expenditure relationship and how this may affect the relationship between DBA and
energy expenditure.
Methods: Here we conducted a methodological study to evaluate the ability of the metric ‘vectorial dynamic body
acceleration’, VeDBA, obtained from tri-axial accelerometer data loggers, to act as a proxy for energy expenditure in
non-uniform environments. We used indirect calorimetry to measure the oxygen consumption (V̇O2) of domestic
sheep (Ovis aries) that were exposed to different ambient temperatures when immobile (resting) and that walked at
various speeds (0.8 to 2.9 km h−
1) and slope angles (− 6° to 6°) on a treadmill while simultaneously measuring tri-axial
acceleration recorded at 40 Hz by body-mounted tags.
Results: The lower critical temperature of sheep was identified as 18 °C, and V̇O2 when they were immobile was
3.67 mL O2
kg−
1 min−
1. There were positive relationships between V̇O2, VeDBA, and speed of walking. However,
VeDBA correlated less well with V̇O2 when the terrain slope either inclined or declined.
Conclusions: We advocate caution when using DBA metrics for establishing energy use in animals moving over
uneven terrain and suggest that each study species or location must be examined on a case-by-case basis. Reliance
upon the relationship described between acceleration and energy expenditure on horizontal-surface treadmills can
lead to potential under- or over-estimates of energy expenditure when animals walk on uneven or inclined ground.Department of Agriculture, Environment and Rural Affairs (DAERA), Northern Ireland provided a studentship to CCM, through which this research was conducted
Evaluating the risk of bovine tuberculosis posed by standard inconclusive reactors identified at backward-traced herd tests in Northern Ireland that disclosed no reactors
Get PDFPublication history: Accepted - 24 January 2022; Published online - 1 March 2022.Bovine tuberculosis is a notifiable disease in Northern Ireland with the national eradication programme of
compulsory testing and slaughter of reactor animals costing approximately £40 million per year. Backward
tracing, known as Backward Check Tests (BCTs), of reactor animals is used to identify previous herds where the
bTB positive animal has resided. The aim of this study was to quantify the bovine tuberculosis (bTB) risk posed
by inconclusive reactors (ICs) at BCTs at both the individual animal and the herd level. ICs to the Comparative
Intradermal Tuberculin Test (CITT) at a BCT, in which no reactors were found, were matched with CITT negative
animals, based on age, sex, test ID and follow up period, in Northern Ireland between 1st January 2008 and 31st
December 2017 (inclusive). A retrospective matched cohort study design was used with the outcome of interest
being the bTB status of each animal and subsequent bTB herd breakdowns. After adjusting for herd size, IC
animals at a BCT had 16 times the odds (95% confidence interval: 7.75 to 38.28, p < 0.001) of becoming bTB
positive compared to CITT negative animals. The percentage population attributable risk was 0.0001%. The
majority 75% (n = 71) of ICs that became bTB positive were identified at the 42 day retest. Of those that were not
disclosed at the 42 day retest (n = 24), almost a third (29%) had moved to an unrestricted herd. However, after
adjusting for herd size and type, herds that had ICs only identified at a BCT did not have an increased odds of a
subsequent bTB herd breakdown compared to herds that had a CITT negative BCT. Given the increased risk posed
by ICs at a BCT, it may be justifiable to remove them from the herd immediately or place them under lifetime
movement restrictions to the herd where they were detected. However, further action regarding the herd of
origin does not appear to be justified
The impact of BCG strains and repeat vaccinations on immunodiagnostic tests in Eurasian badgers (Meles meles)
Get PDFPublication history: Accepted - 29 June 2022; Published online - 9July 2022.Bacille Calmette-Guerin (BCG) is a potential tool in the control of Mycobacterium bovis in European badgers (Meles meles). A five year Test and Vaccinate or Remove (TVR) research intervention project commenced in 2014 using two BCG strains (BCG Copenhagen 1331 (Years 1–3/ BadgerBCG) and BCG Sofia SL2222 (Years 4–5). Badgers were recaptured around 9 weeks after the Year 5 vaccination and then again a year later.
The Dual-Path Platform (DPP) Vet TB assay was used to detect serological evidence of M. bovis infection. Of the 48 badgers, 47 had increased Line 1 readings (MPB83 antigen) between the Year 5 vaccination and subsequent recapture. The number of BCG Sofia vaccinations influenced whether a badger tested positive to the recapture DPP VetTB assay Line 1 (p < 0.001) while the number of BadgerBCG vaccinations did not significantly affect recapture Line 1 results (p = 0.59). Line 1 relative light units (RLU) were more pronounced in tests run with sera than whole blood. The results from an in_house MPB83 ELISA results indicated that the WB DPP VetTB assay may not detect lower MPB83 IgG levels as well as the serum DPP VetTB assay. Changes in interferon gamma assay (IFN-γ) results were seen in 2019 with significantly increased CFP-10 and PPDB readings.
Unlike BadgerBCG, BCG Sofia induces an immune response to MPB83 (the immune dominant antigen in M. bovis badger infection) that then affects the use of immunodiagnostic tests. The use of the DPP VetTB assay in recaptured BCG Sofia vaccinated badgers within the same trapping season is precluded and caution should be used in badgers vaccinated with BCG Sofia in previous years. The results suggest that the DPP VetTB assay can be used with confidence in badgers vaccinated with BadgerBCG as a single or repeated doses.This work was funded by the Department of Agriculture, Environment and Rural Affairs, Northern Ireland (DAERA)
Pasture access and eye temperature in dairy cows
Get PDFPublication history: Published online - 13 April 2022Pasture access can benefit dairy cows’ behavior, health, and welfare, but herds are increasingly housed indoors full-time. Recent infrared thermal-imaging (thermography) studies suggest that higher eye temperatures may be a physiological indicator of chronic stress. We, therefore, hypothesized that, compared to cows with pasture access, cows housed indoors full-time would have higher eye temperatures. In a two-phase crossover experiment, 29 Holstein-Friesian dairy cows experienced 18 days of overnight pasture access and 18 days of full-time indoor housing. We measured each animal’s eye temperature 16 times (eight/phase). During Phase One, cows with pasture access had higher eye temperatures than cows housed indoors full-time (contrary to our hypothesis). However, during Phase Two, cows with pasture access had lower eye temperatures than cows housed indoors full-time. It is, therefore, unclear whether eye temperature reflected disparities in dairy cow welfare between different housing treatments.A.C. was funded by a postgraduate studentship from Northern Ireland’s Department for the Economy. We thank Mike Davies, Helen Kabboush, Deborah McConnell, Gillian Scoley, and Jennifer Weller. AFBI Hillsborough hosted this study, and the Met Office Library and Archive provided meteorological data.
This work was supported by the European Research Council under the European Union's Horizon 2020 research and innovation programme, Grant Number 851145