John S. Church

The use of infrared thermography as an early indicator of bovine respiratory disease complex in calves

Abstract Bovine respiratory disease (BRD) complex causes considerable distress to domestic livestock and economic hardship to the beef industry. Furthermore, the resulting extensive use of antimicrobial treatments is a growing concern from the perspective of facilitating antibiotic resistant microbes. The earlier detection of BRD would enable an earlier, more targeted treatment regime and earlier isolation of infected individuals. The objective of the present study was to investigate the use of non-invasive infrared thermography in the early detection of BRD in cattle. Studies were conducted on 133 head of weaned calves. Data demonstrated that infrared thermography was able to identify animals at early stages of illness, often several days to over one week before clinical signs were manifest. Data indicated that 4–6 days prior to the onset of clinical symptoms of BRD, greater positive and negative predictive values and test efficiency for infrared thermography (80%, 65% and 71%, respectively) compared to the industry standard practice of clinical scoring (70%, 45% and 55%, respectively).

Utility of unmanned aerial vehicles for mapping invasive plant species: a case study on yellow flag iris Iris pseudacorus L.

ABSTRACT This study investigates the utility of an off-the-shelf, consumer-grade unmanned aerial vehicle (UAV) for invasive species mapping in a lacustrine fringe environment. Specifically, this work sought to determine whether such a UAV would be capable of creating accurate maps of the extent of patches of an invasive plant, yellow flag iris (Iris pseudacorus L.), more efficiently than could be accomplished by a traditional field survey, which is often considered in the literature to provide the most accurate maps. The study was conducted at two lakes in the central interior of British Columbia. The UAV used in this study was a DJI Phantom 3 Professional that can acquire images using the built-in 12.4 MP digital camera. This UAV was selected because it is representative of the type of aerial platform that is easily accessible to invasive plant managers in terms of cost, ease of use, and lack of legal restrictions. Three methods of mapping the yellow flag iris were compared: (1) field survey, (2) manual interpretation of the raw UAV-acquired imagery and the orthoimage created from these data, and (3) pixel-based classification of the orthoimage created from the UAV imagery using a random forest classifier. The results revealed that, at both lakes considered, manual interpretation of the UAV-acquired imagery produced the most accurate maps of yellow flag iris infestation, with a false-positive and false-negative classification rate of less than 1%.

Rapid Determination of Total Conjugated Linoleic Acid Content in Select Canadian Cheeses by 1H NMR Spectroscopy

The application of (1)H nuclear magnetic resonance (NMR) spectroscopy to the measurement of conjugated linoleic acid (CLA) content in the lipid fraction of dairy products is both a novel and inviting alternative to traditional methods such as gas chromatography (GC), which can require time-consuming sample derivatization. In this work, a newly developed, rapid, and reliable lipid extraction protocol was combined with simple, nondestructive (1)H NMR spectroscopic analysis to measure the total CLA content in CLA standards and in various Canadian cheeses from conventional, organic, and grass-fed dairy sources. The total CLA concentrations (mg/g cheese) obtained using these new extraction and analysis methods were consistent with amounts found using the modified Folch extraction and GC analysis (correlation coefficient of 0.948). Results showed that cheeses from exclusively grass-fed dairy cows were significantly higher in total CLA content than either conventional or organic cheese.

Prophylactic nitric oxide treatment reduces incidence of bovine respiratory disease complex in beef cattle arriving at a feedlot

Bovine respiratory disease complex (BRDc), is a challenging multi-factorial health issue caused by viral/bacterial pathogens and stressors linked with the transport and mixing of cattle, negatively impacting the cattle feedlot industry. Nitric oxide (NO) is a naturally occurring molecule with antimicrobial attributes. This study tests whether NO can prevent the symptoms associated with BRDc. Eighty-five, crossbred, multiple-sourced, commingled commercial weaned beef calves were monitored and scored for temperature, white blood count, clinical score, hematology, cortisol levels and neutrophil/lymphocyte ratio. NO treatment or placebo were given once on arrival to the stockyard. After one week 87.5% of sick animals were from the control while 12.5% from treatment groups and after two weeks 72% and 28% respectively. Treatment was shown to be safe, causing neither distress nor adverse effects on the animals. These data show that NO treatment on arrival to the feedlot significantly decreased the incidence of BRDc in this study.

Safety, bioavailability and mechanism of action of nitric oxide to control Bovine Respiratory Disease Complex in calves entering a feedlot.

Bovine Respiratory Disease Complex (BRDc), a multi-factorial disease, negatively impacts the cattle industry. Nitric oxide (NO), a naturally occurring molecule, may have utility controlling incidence of BRDc. Safety, bioavailability, toxicology and tolerance/stress of administering NO to cattle is evaluated herein. Thirteen, crossbred, multiple-sourced, commingled commercial weaned beef calves were treated multiple times intranasally over a 4 week period with either a nitric oxide releasing solution (treatment) or saline (control). Exhaled NO, methemoglobin percent (MetHg) and serum nitrites demonstrated biological availability as a result of treatment. Cortisol levels, tissue nitrites, behavior and gross and macroscopic pathology of organs were all normal. Moreover, preliminary in vitro studies using Mannheimia haemolytica, Infectious Bovine Rhinotracheitis, Bovine Parainfluenza-3 and Bovine Respiratory Syncytial Virus, suggest a potential explanation for the previously demonstrated efficacy for BRDc. These data confirm the bioavailability, safety and lack of residual of NO treatment to cattle, along with the bactericidal and virucidal effects.

Separation of dietary omega‐3 and omega‐6 fatty acids in food by capillary electrophoresis

A lower dietary omega-6/omega-3 (n-6/n-3) fatty acid ratio (<4) has been shown to be beneficial in preventing a number of chronic illnesses. Interest exists in developing more rapid and sensitive analytical methods for profiling fatty acid levels in foods. An aqueous CE method was developed for the simultaneous determination of 15 n-3 and n-6 relevant fatty acids. The effect of pH and concentration of buffer, type and concentration of organic modifier, and additive on the separation was investigated in order to determine the best conditions for the analysis. Baseline separations of the 15 fatty acids were achieved using 40 mM borate buffer at pH 9.50 containing 50 mM SDS, 10 mM β-cyclodextrin, and 10% acetonitrile. The developed CE method has LODs of <5 mg/L and good linearity (R(2) > 0.980) for all fatty acids studied. The proposed method was successfully applied to the determination of n-3 and n-6 fatty acids in flax seed, Udo® oils and a selection of grass-fed and grain-fed beef muscle samples.

Non-inferiority of nitric oxide releasing intranasal spray compared to sub-therapeutic antibiotics to reduce incidence of undifferentiated fever and bovine respiratory disease complex in low to moderate risk beef cattle arriving at a commercial feedlot

Undifferentiated fever, or bovine respiratory disease complex (BRDc), is a challenging multi-factorial health issue caused by viral/bacterial pathogens and stressors linked to the transport and mixing of cattle, negatively impacting the cattle feedlot industry. Common practice during processing at feedlots is administration of antibiotic metaphylaxis to reduce the incidence of BRDc. Nitric oxide (NO) is a naturally occurring nano-molecule with a wide range of physiological attributes. This study evaluated the metaphylactic use of intranasal NO releasing spray (NORS) to control BRDc incidence in calves at low-moderate risk of developing BRDc, arriving at a commercial feedlot as compared to conventional antibiotic metaphylaxis. One thousand and eighty crossbred, multiple-sourced, commingled, commercial, weaned beef calves were screened, enrolled, randomized and treated upon arrival. Animals appearing sick were pulled (from their pen) by blinded pen keepers then assessed for BRDc symptoms; blood samples were taken for haptoglobin quantification and the animals were rescued with an antibiotic. After 35 days both groups showed no significant difference in BRDc incidence (5.2% of animals from NORS group and 3.2% from antibiotic group). Average daily weight gain of animals at day 150 for the NORS cohort was 1.17kg compared to 1.18kg for the antibiotic group (p>0.05). There was no significant difference in mortality in the first 35 days (p=0.7552), however, general mortality over 150 days trended higher in the antibiotic cohort. NORS treatment was shown to be safe, causing neither distress nor adverse effects on the animals. This large randomized controlled study in low-moderate BRDc incidence risk calves demonstrates that NORS treatment, as compared to conventional metaphylactic antibiotics, is non-inferior based on BRDc incidence and other metrics like weight and mortality. These data justify further studies in higher BRDc incidence risk populations to evaluate NORS as an alternative strategy to reduce sub-therapeutic metaphylaxis antibiotic use in beef cattle production.

Dexamethasone reduces transport-induced weight losses in beef calves

Dexamethasone was administered intramuscularly at two dose levels (Trial 1 = 0.088 mg kg-1; Trial 2 = 10 mg per calf) to beef calves (Trial 1, n = 60; Trial 2, n = 58) prior to transport by road for 10 and 8 h, to test the effect on transport-induced weight losses. Calves lost significant weight over the transport periods (P < 0.001) but dexamethasone-treated calves lost significantly less weight than control animals (P < 0.004). The relationship between salivary dexamethasone concentrations and weight losses in Trial 1 exhibited a significant trend (r = 0.47, P < 0.06). The correlation of administered dose of dexamethasone (mg kg-1) with weight losses in Trial 2 was significant (r = 0.5, P < 0.006). Dexamethasone administration prior to long-haul transport reduced transport-induced weight losses, and may be an effective method of mitigating transport stress.Key words: Transport, beef calves, dexamethasone, weight losses, salivary cortisol, salivary dexamethasone

Minimally-invasive assessments of the behavioural and physiological effects of enriched colony cages on laying hens

The well-being of laying hens in cages of 5, 10, 20 and 40-birds/cage, and enrichment with perches, nest boxes and scratch pads, was assessed using behavioral and physiological parameters. Laying hens were Lohmann Brown (n = 360) and White Leghorns (n = 360), housed from 17 to 65 weeks of age. Behavioral parameters were; the percentage of birds per cage roosting on perches, claw length (n = 288), and the percentage of eggs laid within nest boxes. Physiological parameters were; the assessment of feather cover from measurements of radiated temperatures by infrared thermography (IRT), bone mineral content of the humerus and femur by quantitative computer tomography (QCT) scans, and adrenocor- tical function as a marker of chronic stress by measurements of corticosterone concentrations in egg yolk and albumin. The majority of eggs (72.7 %) in furnished cages were laid in nest boxes. Nest use was highest in Brown hens (P 80 %, but significantly less in the 10-bird cages (P < 0.0012) due to a shorter perch length. Claws were shorter on birds in cages with scratch pads (P < 0.0001). Feather insulation declined from 35 to 60 weeks of age for breast and back areas (P < 0.0001). White birds exhibited superior breast feather insulation compared to Brown birds. Egg albu- min corticosterone levels declined between 35 and 60 weeks of age (P < 0.011). There were no indications of an affect of colony size or cage enrichment on measurements of bone mineral content. The findings indicated a preference for the use of nest boxes, perches and scratch pads. Significant losses in feather insulation occur with time. A reduction in egg albu- min corticosterone levels over time may be a marker of chronic stress in caged laying hens.

Comparison of fatty acids in beef tissues from conventional, organic and natural feeding systems in western Canada

Turner, T. D., Jensen, J., Pilfold, J. L., Prema, D., Donkor, K. K., Cinel, B., Thompson, D. J., Dugan, M. E. R. and Church, J. S. 2015. Comparison of fatty acids in beef tissues from conventional, organic and natural feeding systems in western Canada. Can. J. Anim. Sci. 95: 49-58. The effect of production system on intramuscular and associated trim fatty acid (FA) profiles of retail ribeye steaks from conventional and niche market organic and natural (grain- or grass-fed) beef were compared. Meat from organic grain- and grass-fed systems was leaner, containing greater proportions of polyunsaturated FA, i.e., 18:3n-3, 20:5n-3, 22:5n-3, 22:6n-3. Correspondingly, the n-6/n-3 ratios of organic grain- and grass-fed systems were 3:1, while conventional and natural grain systems had ratios of 8:1. High forage-to-grain ratio production systems increased proportions of desirable biohydrogenation intermediates (BI), including t11-18:1 and c9,t11-18:2, whereas conventional and natural grain systems elevated t10-18:1. Trim fat was similarly affected by production system, and was a relatively richer source of BI. Overall, proportions of desirable FAs, including n-3 and BI, were greater for organic grain- and grass-fed systems, emphasizing the importance of a high forage-to-grain ratio to enhance the healthfulness of beef, whereas conventional and natural grain-fed systems were largely equivalent.