Gariepy T.D.,Agriculture and Agri Food Canada |
Haye T.,CABI Inc |
Fraser H.,Ontario Ministry of Agriculture and Food |
Zhang J.,MoA CABI Joint Laboratory for Biosafety
Journal of Pest Science | Year: 2014
Halyomorpha halys has recently established in countries outside of its Asian area of origin. In the North Eastern USA, this pest causes severe economic loss in agricultural crops. Breeding populations have been confirmed in Switzerland and Canada; however, their pathways of entry and genetic diversity remain unknown. To determine invasion pathways and source population(s), the diversity of specimens from Asia, North America, and Europe was investigated. Genetic diversity in Asia was higher than that in the Canada and Switzerland. Although three haplotypes were detected among Canadian H. halys, one haplotype dominated. In contrast, two out of three haplotypes were found frequently among Swiss samples. Based on molecular data and interception records it appears likely that H. halys in Canada is derived from the movement of established US populations. Further, North American populations likely originated from the Hebei/Beijing regions of China. The area of origin of the Swiss samples remains unclear. Although the dominant haplotype in Switzerland was consistent with Asian samples collected in the Hebei and Beijing provinces, it was not the dominant haplotype in these regions and further sampling is necessary to its confirm the distribution and abundance in the area of origin. The remaining two haplotypes were unique to Switzerland and no matches were found among our Asian samples. Interestingly, no haplotypes were shared between the North American and Swiss samples, indicating that the two invasions were separate and distinct events and did not result from the movement of goods and materials between USA and Europe. © 2013 Her Majesty the Queen in Right of Canada.
VanderZaag A.C.,Agriculture and Agri Food Canada |
Flesch T.K.,University of Alberta |
Desjardins R.L.,Agriculture and Agri Food Canada |
Balde H.,Agriculture and Agri Food Canada |
Wright T.,Ontario Ministry of Agriculture and Food
Agricultural and Forest Meteorology | Year: 2014
There is a need to improve the understanding of methane (CH4) emissions on multiple spatial and temporal scales, and on a sector basis. Livestock are significant contributors to the CH4 budget, with emissions coming from enteric fermentation by ruminants and management of liquid manure. Inventory estimates for methane emissions are based on methodology that needs to be verified with actual on-farm measurements. Responding to these needs, the objectives of this study were to apply the backward Lagrangian Stochastic (bLS) technique on small dairy farms (50-100 lactating cows) and to examine its suitability to determine CH4 emissions from whole farms and partition emissions from cattle and manure. Measurement campaigns were selected to characterize the emission response to farm management activities and seasonal changes. At both farms the whole-farm emission rate was measured when the liquid manure storages were either full or emptied. Emissions from manure were substantial, and in the fall when the manure storage was full, 60% of the whole farm emissions came from the manure storage. Substantial seasonal differences in whole-farm emissions were observed, with fall season emissions being ~40% higher than in the spring due to much higher manure emissions in the fall (673glactating-cow-1d-1) than the spring (249glactating-cow-1d-1). Peak emissions from stored manure were 47kgCH4h-1, (730glactating-cow-1h-1) during agitation. The enteric emission rate from the animals (after subtracting estimated barn floor emissions) showed clear diurnal variation and on a daily basis was similar for both seasons, ranging between 270 and 380glactating cow-1d-1. Implied Ym values were lower than the IPCC default value. Methane emissions from manure exhibited pronounced temporal variation on multiple time-frames and as a result, more research is needed to fully describe annual CH4 emissions from liquid manure management. © 2014 Crown Copyright and Elsevier BV.
PubMed | University of Guelph, Iowa State University, Ontario Ministry of Agriculture and Food and Health science Center
Type: Evaluation Studies | Journal: Journal of animal science | Year: 2014
The objective of this study was to determine the effectiveness of a nonpenetrating captive bolt, Zephyr-E, for euthanasia of suckling and weaned pigs from 3 to 9 kg (5-49 d of age) using signs of insensibility and death as well as postmortem assessment of traumatic brain injury (TBI). The Zephyr-E was used by 15 stock people to euthanize 150 compromised pigs from 4 farrowing and nursery units from commercial farms and 2 research stations. Brainstem reflexes, convulsions, and heartbeat were used to assess insensibility, time of brain death, and cardiac arrest following Zephyr-E application. Skull fracture displacement (FD) was quantified from computed tomography (CT) scans (n = 24), macroscopic scoring was used to assess brain hemorrhage and skull fracture severity (n = 150), and microscopic scoring was used to assess subdural hemorrhage (SDH) and parenchymal hemorrhage within specific brain regions that are responsible for consciousness and vital function (n = 32). The Zephyr-E caused immediate, sustained insensibility until death in 98.6% of pigs. On average, clonic convulsions (CC) ceased in 82.2 s ( 3.4 SE), brain death was achieved in 144.9 s ( 5.4 SE), and cardiac arrest occurred in 226.5 s ( 8.7 SE). Time of brain death and cardiac arrest differed significantly among stock people (P = 0.0225 and P = 0.0369). Age was positively related to the duration of CC (P = 0.0092), time of brain death (P = 0.0025), and cardiac arrest (P = 0.0068) with shorter durations seen in younger pigs. Average FD was 8.3 mm ( 1.0 SE). Macroscopic scores were significantly different among weight classes for subcutaneous (P = 0.0402) and subdural-ventral (P = 0.0037) hemorrhage with the lowest severity hemorrhage found in the 9-kg weight category. Microscopic scores differed among brain sections (P = 0.0070) for SDH with lower scores found in the brainstem compared to the cerebral cortex and midbrain. Parenchymal hemorrhage differed among brain sections (P = 0.0052) and weight categories (P = 0.0128) with the lowest scores in the midbrain and brainstem and the 7- and 9-kg weight categories. The Zephyr-E was highly effective for the euthanasia of pigs up to 9 kg (49 d) based on immediate insensibility sustained until death. Postmortem results confirmed that severe skull fracture and widespread brain hemorrhage were caused by the Zephyr-E nonpenetrating captive bolt.
Congreves K.A.,University of Guelph |
Smith J.M.,Agriculture and Agri Food Canada |
Nemeth D.D.,Ontario Ministry of Agriculture and Food |
Hooker D.C.,University of Guelph |
Van Eerd L.L.,University of Guelph
Canadian Journal of Soil Science | Year: 2014
Soil organic carbon (SOC) is crucial for maintaining a productive agro-ecosystem. Long-term research must be synthesized to understand the effects of land management on SOC storage and to develop best practices to prevent soil degradation. Therefore, this review compiled an inventory of long-term Ontario studies and assessed SOC storage under common Ontario land management regimes via a meta-analysis and literature review. In general, greater SOC storage occurred in no-till (NT) vs. tillage systems, in crop rotation vs. continuous corn, and in N fertilizer vs. no N fertilizer systems; however, soil texture and perhaps drainage class may determine the effects of tillage. The effect on SOC storage was variable when deeper soil depth ranges (0-45 cm) were considered for NT and rotational cropping, which suggests an unpredictable effect of land management on SOC at depths below the plough layer. Therefore, researchers are encouraged to use the presented inventory of nine long-term research sites and 18 active experiments in Ontario to pursue coordinated studies of long-term land management on SOC at depths extending below the plough layer.
Alton G.D.,University of Guelph |
Pearl D.L.,University of Guelph |
Bateman K.G.,University of Guelph |
McNab B.,Ontario Ministry of Agriculture and Food |
Berke O.,University of Guelph
BMC Veterinary Research | Year: 2013
Background: Abattoir condemnation data show promise as a rich source of data for syndromic surveillance of both animal and zoonotic diseases. However, inherent characteristics of abattoir condemnation data can bias results from space-time cluster detection methods for disease surveillance, and may need to be accounted for using various adjustment methods. The objective of this study was to compare the space-time scan statistics with different abilities to control for covariates and to assess their suitability for food animal syndromic surveillance. Four space-time scan statistic models were used including: animal class adjusted Poisson, space-time permutation, multi-level model adjusted Poisson, and a weighted normal scan statistic using model residuals. The scan statistics were applied to monthly bovine pneumonic lung and " parasitic liver" condemnation data from Ontario provincial abattoirs from 2001-2007.Results: The number and space-time characteristics of identified clusters often varied between space-time scan tests for both " parasitic liver" and pneumonic lung condemnation data. While there were some similarities between isolated clusters in space, time and/or space-time, overall the results from space-time scan statistics differed substantially depending on the covariate adjustment approach used.Conclusions: Variability in results among methods suggests that caution should be used in selecting space-time scan methods for abattoir surveillance. Furthermore, validation of different approaches with simulated or real outbreaks is required before conclusive decisions can be made concerning the best approach for conducting surveillance with these data. © 2013 Alton et al.; licensee BioMed Central Ltd.
Lum G.B.,University of Guelph |
Shelp B.J.,University of Guelph |
DeEll J.R.,Ontario Ministry of Agriculture and Food |
Bozzo G.G.,University of Guelph
Plant Science | Year: 2016
In combination with low temperature, controlled atmosphere storage and 1-methylcyclopropene (ethylene antagonist) application are used to delay senescence of many fruits and vegetables. Controlled atmosphere consists of low O2 and elevated CO2. When sub-optimal partial pressures are used, these practices represent multiple abiotic stresses that can promote the development of physiological disorders in pome fruit, including flesh browning and cavities, although there is some evidence for genetic differences in susceptibility. In the absence of surface disorders, fruit with flesh injuries are not easily distinguished from asymptomatic fruit until these are consumed. Oxidative stress metabolites tend to accumulate (e.g., γ-aminobutyrate) or rapidly decline (e.g., ascorbate and glutathione) in vegetative tissues exposed to hypoxic and/or elevated CO2 environments. Moreover, these phenomena can be associated with altered energy and redox status. Biochemical investigations of Arabidopsis and tomato plants with genetically-altered levels of enzymes associated with the γ-aminobutyrate shunt and the ascorbate-glutathione pathway indicate that these metabolic processes are functionally related and critical for dampening the oxidative burst in vegetative and fruit tissues, respectively. Here, we hypothesize that γ-aminobutyrate accumulation, as well energy and antioxidant depletion are associated with the development of physiological injury in pome fruit under multiple environmental stresses. An improved understanding of this relationship could assist in maintaining the quality of stored fruit. © 2016 Elsevier Ireland Ltd.
Wagner A.E.,University of Guelph |
Wu P.F.,Ontario Ministry of Agriculture and Food
American Society of Agricultural and Biological Engineers Annual International Meeting 2014, ASABE 2014 | Year: 2014
Bovine spongiform encephalopathy (BSE) is a neurodegenerative disease that can transmit from cattle to humans. Humans can contract a variant version of the disease, named variant Creutzfeldt-Jakob disease (vCJD), from the consumption of beef infected with BSE. The infective agent is a misfolded protein called prion, which concentrates in tissues including the skull, brain, trigeminal ganglia, eyes, tonsils, spinal cord and dorsal root ganglia of cattle aged 30 months or older, and distal ileum of cattle of all ages. These tissues are collectively known as specified risk material (SRM). SRM are required to be removed from all cattle slaughtered for human consumption, and are also banned from all animal feeds, pet foods and fertilizers. In Ontario, Canada, acceptable disposal methods include destruction by incineration, alkaline hydrolysis and thermal hydrolysis. Alternatively, SRM can be disposed of by permanent containment. Methods of containment include burial and use of sanitary landfills operating under provincial jurisdiction as waste disposal site. Composting and rendering are acceptable intermediate steps used to reduce the SRM volume and to convert the SRM into a fuel source for final destruction.
Fraser H.W.,Ontario Ministry of Agriculture and Food
American Society of Agricultural and Biological Engineers Annual International Meeting 2014, ASABE 2014 | Year: 2014
Noise, is unwanted sound and is perceived as an environmental nuisance. Noise is also seen as intrusive into personal privacy, while its meaning for any individual is important in determining whether that person will be annoyed by it. Although rural areas are generally quiet, farmers live in a competitive world and modem farms sometimes use noisy stationary equipment. However, it is important to understand that just being able to detect a sound does not automatically mean it is a nuisance. Unresolved noise problems can result in poor neighbour relationships. This paper provides background information on describing agricultural noise nuisance; attenuation of sound; low-cost, farmer-friendly sound absorbent and barrier materials that might be used to reduce sound at the source; and thoughts how setbacks from stationary farm equipment to neighbours (and vice versa) might be applied.
PubMed | University of Guelph and Ontario Ministry of Agriculture and Food
Type: | Journal: Plant science : an international journal of experimental plant biology | Year: 2016
In combination with low temperature, controlled atmosphere storage and 1-methylcyclopropene (ethylene antagonist) application are used to delay senescence of many fruits and vegetables. Controlled atmosphere consists of low O2 and elevated CO2. When sub-optimal partial pressures are used, these practices represent multiple abiotic stresses that can promote the development of physiological disorders in pome fruit, including flesh browning and cavities, although there is some evidence for genetic differences in susceptibility. In the absence of surface disorders, fruit with flesh injuries are not easily distinguished from asymptomatic fruit until these are consumed. Oxidative stress metabolites tend to accumulate (e.g., -aminobutyrate) or rapidly decline (e.g., ascorbate and glutathione) in vegetative tissues exposed to hypoxic and/or elevated CO2 environments. Moreover, these phenomena can be associated with altered energy and redox status. Biochemical investigations of Arabidopsis and tomato plants with genetically-altered levels of enzymes associated with the -aminobutyrate shunt and the ascorbate-glutathione pathway indicate that these metabolic processes are functionally related and critical for dampening the oxidative burst in vegetative and fruit tissues, respectively. Here, we hypothesize that -aminobutyrate accumulation, as well energy and antioxidant depletion are associated with the development of physiological injury in pome fruit under multiple environmental stresses. An improved understanding of this relationship could assist in maintaining the quality of stored fruit.
Controlled atmosphere-related injury in ‘Honeycrisp’ apples is associated with γ-aminobutyrate accumulation [Les dommages causés aux pommes Honeycrisp sous atmosphère contrô lée sont liés à l’accumulation de γ-aminobutyrate]
Chiu G.Z.,University of Guelph |
Shelp B.J.,University of Guelph |
Bowley S.R.,University of Guelph |
Deell J.R.,Ontario Ministry of Agriculture and Food |
. Bozzo G.G.,University of Guelph
Canadian Journal of Plant Science | Year: 2015
‘Honeycrisp’ apples (Malus × domestica Borkh.), including fruit treated with the ethylene antagonist 1-methylcyclopropene (1-MCP), can be susceptible to controlled atmosphere (CA)-related injury of the flesh tissue during storage. To better understand the biomarkers associated with this physiological disorder, we compared the temporal responses of the universal stress signature, γ-aminobutyrate (GABA), and visual symptoms of CA-related injury in apples subjected to elevated CO2. Fruit were treated with or without 1-MCP prior to CA [2.5 kPa O2, 5 (elevated) or 0.03 (ambient) kPa CO2] storage at either 3 or 20°C for up to 24 wk. At 208C, 1-MCP-treated apples displayed symptoms of CA-related injury by 3 wk of elevated CO2 storage; a similar 15% disorder incidence was apparent by 6 wk in non 1-MCP-treated fruit. A maximal incidence of 30% for this disorder occurred after 24 wk at 3°C in fruit held at elevated CO2, regardless of 1-MCP treatment. At 20°C, GABA levels were 48% higher within 6 wk of the transfer of 1-MCP-treated fruit to elevated CO2. At 3°C, a 2.6-fold increase in GABA level occurred by week 6 of elevated CO2 storage, and was maintained for an additional 18 wk thereafter; a similar change in GABA level was apparent in non 1-MCP-treated fruit, albeit delayed until week 18 of storage. These findings indicate that shifts in GABA are associated with the onset of visual symptoms of CA-related injury in ‘Honeycrisp’ fruit in response to elevated CO2, regardless of 1-MCP. © 2015, Agricultural Institute of Canada. All rights reserved.