A study on the applicability of implantable microchip transponders for body temperature measurements in pigs

Background

The applicability of an electronic monitoring system using microchip transponders for measurement of body temperatures was tested in 6-week-old conventional Danish weaners infected with classical swine fever virus (CSFV). Subcutaneous tissue temperatures obtained by the implantable transponders were compared with rectal temperatures, recorded by a conventional digital thermometer.

Methods

In a preliminary study, transponders were inserted subcutaneously at 6 different positions of the body of 5 pigs. The transponders positioned by the ear base provided the best correlation to rectal temperature. To test the stability of the monitoring system in a larger group of pigs, transponders were therefore inserted by the left ear base in a subsequent infection experiment with 30 pigs.

Results

Generally, the microchip transponders measured a subcutaneous tissue temperature, which was about 1°C lower than the rectal temperature. However, a simple linear relationship between the measures of the two methods was found.

Conclusions

Our study showed that the tested body monitoring system may represent a promising tool to obtain an approximate correlate of body temperatures in groups of pigs. In contrast, however, the tested system did not constitute a suitable tool to measure body temperatures of individual animals in the present pig infection experiment.     

Recombinant <Emphasis Type="Italic">Moraxella bovoculi</Emphasis> cytotoxin-ISCOM matrix adjuvanted vaccine to prevent naturally occurring infectious bovine keratoconjunctivitis

A randomized, blinded, controlled field trial was conducted during summer 2006 in a northern California, USA, herd of beef cattle to evaluate the efficacy of a recombinant Moraxella bovoculi cytotoxin subunit vaccine to prevent naturally occurring infectious bovine keratoconjunctivitis (IBK; pinkeye). A convenience sample comprised of 127 steers were administered a subcutaneous dose of either adjuvant alone (ISCOM matrices; control group) or recombinant M. bovoculi cytotoxin carboxy terminus adjuvanted with ISCOM matrices (MbvA group) and were boostered 21 days later. The steers were examined once weekly for 15 weeks for evidence of IBK. No significant difference in the cumulative proportion of corneal ulcerations was detected between groups. Compared to the control calves, the MbvA vaccinates had significantly higher increases in serum neutralizing titers to M. bovoculi hemolysin between week 0 and week 6. The prevalence of M. bovis isolations was higher from ulcerated eyes of calves vaccinated with MbvA as compared to control calves. Vaccination of calves against the carboxy terminus of M. bovoculi RTX toxin resulted in significant increases in serum hemolysin neutralizing titers and may modulate organism type cultured from ulcerated eyes of calves in herds where both M. bovis and M. bovoculi exist. Use of M. bovoculi antigens alone in vaccines to prevent IBK may not be beneficial in herds where IBK is associated with both M. bovoculi and M. bovis.     

Automated counting of nucleated cells in equine synovial fluid without and with hyaluronidase pretreatment

Background: Microscopy is usually used to obtain manual total and differential cell counts in equine synovial fluid. A faster, more precise method is desirable. Objectives: The objectives were to compare an automated impedance method with a manual method for obtaining total and differential cell counts in equine synovial fluid and to evaluate the effect of pretreatment with hyaluronidase on automated results. Methods: Synovial fluid samples (n=48) were collected into EDTA and analyzed within 48 hours. Automated total and differential cell counts were evaluated using a Medonic CA620‐VET hematology analyzer before and after pretreatment for 5–30 minutes with hyaluronidase (final concentration 0.01 mg/mL). A hemacytometer count and microscopic evaluation of a direct smear were used as the reference method. Intra‐assay coefficients of variation (CV) were determined. Results: Thirty‐one of 46 untreated samples and 0/46 hyaluronidase‐treated samples were error‐flagged by the analyzer. Correlation between automated (ANCC) and manual (MNCC) nucleated cell counts in untreated samples (n=15; R²=0.93) and pretreated samples (n=46; R²=0.94) was high, and pseudomedian difference was low. Intra‐assay CVs for samples with medium and high cellularity were significantly lower for ANCC (1.5–2.7%) compared with MNCC (6.1–15.7%) (P<.01). Valid automated differential cell counts were not obtained. Conclusions: Automated total cell counts obtained on the Medonic analyzer correlate well with manual counts in equine synovial fluid; however, pretreatment with hyaluronidase is required to minimize error flags. Automated differential counts are not accurate for synovial fluid.     

Reducing the impact of blue mussel (Mytilus edulis) dredging on the ecosystem in shallow water soft bottom areas

• Dredging blue mussels (Mytilus edulis) and thus removing structural elements, inducing resuspension of sediment as well as reducing filtration capacity, will inevitably affect the ecosystem. The study demonstrates that the impacts of fishing can be reduced through gear developments.
• A new light dredge was tested on commercial vessels using two different experimental setups. First, a twin haul experiment tested the standard gear (i.e., a Dutch dredge) against the light dredge by fishing the two gears side by side onboard the same vessel. Second, a single dredge experiment tested the absolute performance of the two gears by fishing in areas with a known blue mussel density.
• Results from the twin haul experiment demonstrate that the weight of sediment retained in the gear per square metre fished is 49% less in the light dredge compared with the Dutch dredge which will reduce resuspension of sediment at the surface. Also, the drag resistance of the light dredge was significantly less (177.1 vs. 202.7 kg m^‐1). In the twin haul experiment no significant difference was found in the catch per unit effort (CPUE) of the two gears. The single dredge experiment, on the other hand, demonstrated a significant increase in CPUE exceeding 200% when using the light dredge.
• Seafloor tracks made by the two dredges could not be distinguished by use of side‐scan sonar and the tracks were still detectable 2 months after fishing.
• It was concluded that replacement of the Dutch dredge with the light dredge would reduce the impact of the fishery on the ecosystem by (i) reducing resuspension of sediment, (ii) reducing fuel consumption, and (iii) potentially reducing energy transfer to the sediment through a reduced gear drag resistance. A potential increase in catch efficiency may reduce the area affected.
• Fishing with the light dredge is discussed in relation to management of Natura 2000 sites.

Copyright © 2014 John Wiley & Sons, Ltd.     

Soil feedback on plant growth in a sub-arctic grassland as a result of repeated defoliation

In the long term, defoliation of plants can be hypothesized to decrease plant carbon supply to soil decomposers and thus decrease decomposer abundance and nutrient mineralization in the soil. To test whether defoliation creates changes in soil that can feedback to plant growth, we collected soil from sub-arctic grassland plots that had been either defoliated or non-defoliated for three years and followed the growth of different plant species combinations in these soils in greenhouse conditions. Plant N acquisition and plant growth were lower in the soil collected from the defoliated field plots than in the soil collected from the non-defoliated plots. This response did not depend on the species composition or richness of the tested plant community. In the field, defoliation decreased net nitrogen mineralization. Despite the negative effect of decreased nutrient mineralization rate on plant growth and N accumulation in the greenhouse test, the aboveground abundance of most plant species was not affected by defoliation in the field. This indicates that plants in these sub-arctic grasslands can at least temporarily overcome defoliation-induced decrease in soil nutrient availability. To our knowledge, our results are the first direct evidence that defoliation can induce changes in the soil that negatively feedback to plant growth and N accumulation. This finding indicates that, especially in arctic and sub-arctic grasslands where nutrient mineralization rates are inherently low, soil feedbacks can have an important role in the outcome of herbivore–plant interactions.     

Phytochemical diversity in tubers of potato cultivars and landraces using a GC-MS metabolomics approach

Phytochemical diversity with respect to a range of polar (including amino acids, organic acids, sugars, and sugar alcohols) and nonpolar (including fatty acids, alkanols, and sterols) metabolites was examined within tubers from a total of 29 genetically diverse potato cultivars and Chilean landraces using a metabolomics approach by gas chromatography-mass spectrometry. From principal component analysis of the polar and nonpolar metabolite data there was insufficient variation to differentiate the majority of cultivars and landraces. Analysis of all polar metabolite profiles revealed separation of two cultivars (Glenna and Morag) from the other cultivars and landraces and a separate cluster of one landrace line, largely due to higher levels of sugars. Pentland Javelin was distinct in containing high levels of many amino acids. The two Solanum tuberosum group phureja cultivars (Inca Sun and Mayan Gold) were not particularly similar and were not separated from the S. tuberosum group tuberosum cultivars. Analysis of the nonpolar metabolite data revealed partial separation of two landrace lines and, on the basis of some minor fatty acids, Mayan Gold was distinct. The differences in metabolite profiles are considered in terms of the taxonomy and breeding history of the cultivars and possible influences from other factors such as developmental stage of the tuber. With a view to exploring biosynthetic links between metabolites, a pairwise correlation analysis was performed on all metabolites. The significance of high correlations between many amino acids and between several nonpolar metabolites is discussed.     

Perceptions of New Zealand nutrition labels by Māori, Pacific and low-income shoppers

BACKGROUND: In New Zealand the burden of nutrition-related disease is greatest among Māori, Pacific and low-income peoples. Nutrition labels have the potential to promote healthy food choices and eating behaviours. To date, there has been a noticeable lack of research among indigenous peoples, ethnic minorities and low-income populations regarding their perceptions, use and understanding of nutrition labels. Our aim was to evaluate perceptions of New Zealand nutrition labels by Māori, Pacific and low-income peoples and to explore improvements or alternatives to current labelling systems. METHODS: Māori, Samoan and Tongan researchers recruited participants who were regular food shoppers. Six focus groups were conducted which involved 158 people in total: one Māori group, one Samoan, one Tongan, and three low-income groups. RESULTS: Māori, Pacific and low-income New Zealanders rarely use nutrition labels to assist them with their food purchases for a number of reasons, including lack of time to read labels, lack of understanding, shopping habits and relative absence of simple nutrition labels on the low-cost foods they purchase. CONCLUSIONS: Current New Zealand nutrition labels are not meeting the needs of those who need them most. Possible improvements include targeted social marketing and education campaigns, increasing the number of low-cost foods with voluntary nutrition labels, a reduction in the price of 'healthy' food, and consideration of an alternative mandatory nutrition labelling system that uses simple imagery like traffic lights.     

Biochar properties and soil type drive the uptake of macro‐ and micronutrients in maize (Zea mays L.)

The use of biochar in agriculture is a promising management tool to mitigate soil degradation and anthropogenic climate change. However, biochar effects on soil nutrient bioavailability are complex and several concurrent processes affecting nutrient bioavailability can occur in biochar‐amended soils. In a short‐term pot experiment, the concentration of N, P, K, S, Ca, Mg, Cu, Zn, Mn, B, Fe, and Na in the shoots of maize grown in three different soil types [sandy soil (S1), sandy loam (S2), and sandy clay loam (S3)] was investigated. The soils were either unamended or amended with two different biochars [wheat straw biochar (SBC) or pine wood biochar (WBC)] at two P fertilizer regimes (–/+ P). We used three‐way ANOVA and Principal Component Analyses (PCA) of transformed ionomic data to identify the effects of biochar, soil, and P fertilizer on the shoot nutrient concentrations. Three distinct effects of biochar on the shoot ionome were detected: (1) both biochars added excess K to all three soils causing an antagonistic effect on the uptake of Ca and Mg in maize shoots. (2) Mn uptake was affected by biochar with varying effects depending on the combined effect of biochar and soil properties. (3) WBC increased maize uptake of B, despite the fact that WBC increased soil pH and added additional calcite to the soil, which would be expected to reduce B bioavailability. The results of this study highlight the fact that the bioavailability of several macro and micronutrients is affected by biochar application to soil and that these effects depend on the combined effect of biochar and soils with different properties.