Short-term responses of soil physical properties to corn tillage-planting systems in a humid maritime climate

The fertile, but naturally poorly drained soils of the western Fraser Valley in British Columbia, Canada are located in an area subject to about 1200 mm of rainfall annually. These soils were under intensive conventional tillage practices for years, which contributed to their poor infiltrability, low organic matter, and overall poor structure. Development of tillage practices that incorporate winter cover crops and reduce traffic in spring is required to reduce local soil degradation problems. The objective of this study was to determine short-term responses of soil physical properties to fall and spring tillage (ST) and fall and no spring tillage (NST) systems, both using spring barley (Hordeum vulgare L.) and winter wheat (Triticum aestivum L.) as winter cover crops. Field experiments were conducted for 3 years following seeding of the winter cover crops in fall 1992 on a silty clay loam Humic Gleysol (Mollic Gleysol in FAO soil classification). Average aeration porosity was 0.15 m³ m⁻³ on NST and 0.22 m³ m⁻³ on ST, while bulk density was 1.22 Mg m⁻³ on NST and 1.07 Mg m⁻³ on ST at the 0–7.5 cm depth. Neither of these two soil properties should limit seedling and root growth. After ST, mechanical resistance was consistently greater for 500–1000 kPa in NST than in ST, but never reached value of 2500 kPa considered limiting for root growth. The NST system did not increase soil water content relative to ST, with soil water contents being similar at 10 and 40 cm depth in all years. In 2 out of 3 years NST soil was drier at the 20 cm depth than was ST soil. Three years of NST did not result in a significant changes of aggregate stability relative to ST. This experiment showed that limiting tillage operations to the fall did not adversely affect soil physical conditions for plant growth in a humid maritime climate.     

The Solar Acoustic Spectrum and Eigenmode Parameters

The Global Oscillation Network Group (GONG) project estimates the frequencies, amplitudes, and linewidths of more than 250,000 acoustic resonances of the sun from data sets lasting 36 days. The frequency resolution of a single data set is 0.321 microhertz. For frequencies averaged over the azimuthal order m, the median formal error is 0.044 microhertz, and the associated median fractional error is 1.6 x 10(-5). For a 3-year data set, the fractional error is expected to be 3 x 10(-6). The GONG m-averaged frequency measurements differ from other helioseismic data sets by 0.03 to 0.08 microhertz. The differences arise from a combination of systematic errors, random errors, and possible changes in solar structure.     

Antimicrobial resistance of Salmonella and generic Escherichia coli isolated from surface water samples used for recreation and a source of drinking water in southwestern Ontario,Canada

Antimicrobial resistance (AMR) in the aquatic environment represents an important means of introduction and dissemination of resistance genes, and presence of resistant pathogens in surface waters may pose a public health concern to recreational and drinking water users. The purpose of this study was to explore antimicrobial resistance patterns in water samples collected from the Grand River watershed (southwestern Ontario, Canada) to describe the composition, trends and potential risks of AMR in the aquatic environment. As part of FoodNet Canada and the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS), stream water samples were collected bi‐weekly from sampling sites within the Grand River watershed in the Waterloo, Ontario sentinel site and tested for the presence and antimicrobial susceptibility of Salmonella spp. (2005–2013) and generic Escherichia coli (2012–2013). Of all samples tested, 16% of Salmonella and 22% of E. coli isolates were resistant to at least one antimicrobial, including three Salmonella isolates and two E. coli isolates that were resistant to Category I antimicrobials, which are classified as very high importance for the treatment of serious bacterial infections in humans. The greatest proportion of resistant E. coli isolates were observed from the river site upstream of the drinking water intake, while the greatest proportion of resistant Salmonella isolates were from sites upstream in the watershed, and at one recreational water site. Salmonella resistance trends remained fairly stable between 2007 and 2013, with the exception of streptomycin and tetracycline which increased in 2010 and 2013. Continued surveillance of antimicrobial resistance patterns and exploration of risk factor data will allow for a better understanding of resistance transmission in the aquatic environment.     

Effect of polyoxyethylene and polyoxypropylene nonionic block copolymers on performance and recruitment of immune cell subsets in weaned pigs

Background

Because European-wide directives are restricting the non-clinical use of antibiotics as in-feed growth promotors in swine production, there is an intensive search for alternative strategies for control and prevention of losses among young pigs. With the growing knowledge of the porcine immune system and its endogenous modulation, it has been clearly established that exogenous immunomodulation using adjuvants and immune response modifiers (IRMs) represents an important prophylactic/therapeutic approach in the prevention/treatment of both stress- and microbial-induced disorders that accompaning weaning. However, it is essential to select a fully evaluated agent which may act either as a nonspecific IRM or synergistically as an adjuvant with vaccines. The synthetic macromolecules with a long history as adjuvant and IRM are nonionic block copolymers which consist of polyoxyethylene (POE) and polyoxypropylene (POP) molecules.

Methods

The aim of this work was to evaluate the effectiveness of POE-POP given as a single peroral dose on productivity parameters such as body weight gain, feed intake and feed conversion ratio, and systemic and intestinal immune parameters by assessing the proportions of CD45⁺ lymphoid cells, CD4⁺ and CD8⁺ T cells, and CD21⁺ B cells in the peripheral blood as well as the number of CD45RA⁺ naive lymphoid cells residing in the ileal mucosa in weaned pigs during a follow-up study 5 weeks after the treatment.

Results

Pigs treated with POE-POP had better feed intake (+ 14.57%), higher average body mass at the end of the experiment (20.91 kg vs. 17.61 kg), and higher body weight gain in relation to Day 0 (191.63% vs. 144.58%) as well as in relation to nontreated pigs (+ 18.74%), with a lower feed conversion ratio (− 30.26%) in comparison to the control pigs. A much lower diarrhea severity score (5 vs. 54) was recorded in pigs treated with POE-POP (− 90.74%) than in the control pigs. A higher average diarrhea severity (ADS) was recorded in the control pigs (1.54 vs. 0.14), whereas the treatmant group had much a lower ADS ratio (− 90.91%) after 35 days of the experiment. The pigs that were treated with POE-POP had an increased proportion of CD45⁺, CD4⁺ and CD8⁺ cells at Day 21 (at p < 0.05, p < 0.05 or p < 0.01, respectively), Day 28 (at p < 0.01, respectively) and Day 35 (at p < 0.01, p < 0.05 or p < 0.01, respectively) as well as of CD21⁺ cells at Day 28 (p < 0.05) and Day 35 of the experiment (p < 0.01). Also, these pigs had more numerous CD45RA⁺ cells in interfollicular (p < 0.05) and follicular areas (p < 0.01) of the ileal Peyer’s patches than did control pigs.

Conclusion

This property of POE-POP to induce recruitment of circulating and intestinal immune cell subsets in weaned pigs may allow the use of IRM-active block copolymers as adjuvants for vaccines, particularly those orally delivered and targeted to the gut-associated lymphoid tissues that are well known to promote rather tolerogenic than protective immune responses.     

Broiler chicken health, welfare and fluctuating asymmetry in organic versus conventional production systems

The aim of this study was to test three predictions: (1) that a combination of animal-based parameters indicates better health and welfare in broilers from organic versus conventional farms, (2) that broilers from organic farms show less fluctuating asymmetry (FA) than broilers from conventional farms, and (3) that, at the level of the individual bird, the relationship between FA and welfare is negative and strongest in conventional broilers. On 140 slaughter-age birds randomly selected from seven organic and seven conventional flocks in Belgium we measured standardised FA and five conventional animal-based welfare indicators (tonic immobility duration, latency-to-lie, and condition of the foot pad, hock, and breast). The caeca from the birds from four organic and four conventional flocks were removed for assessing the presence of two bacterial pathogens (Salmonella and Campylobacter) and the concentration of the health-promoting lactic acid bacteria. Finally, the blood serum concentration of the acute phase protein alpha-1-acid glycoprotein (AGP), a non-specific indicator of immunological stress, was determined. Salmonella was found in the caeca content of two (2.5%) birds only (both from the same conventional farm), whereas 44 (55.7%) birds were infected with Campylobacter. The prevalence of Campylobacter, the concentration of lactic acid bacteria, the duration of tonic immobility, and the condition of the breast and foot pad did not differ between both production systems. Apart from a higher concentration of AGP, organic birds had better scores for hock condition and a longer latency-to-lie indicating better leg health. In addition, organic birds scored better on the aggregated welfare index (i.e. the average of the five standardised welfare indicators). As both production systems differed in many aspects (e.g. slower-growing genotypes, slaughter age, feed, stocking density, group size) it is impossible to assign differences in welfare/health indicators to a single factor. Whatever the causes may be our findings suggest that, despite the potentially elevated risk of immunological challenge, broiler chicken welfare is generally superior in organic farms as compared with conventional farms in Belgium. Regarding the validity of FA as welfare indicator, the prediction of lower FA in the population with highest aggregated welfare score was confirmed but, at the level of the individual, no associations between FA and the aggregated welfare index were found irrespective of whether data from organic and conventional broilers were analysed separately or combined.     

Simultaneous zoonotic transmission of Chlamydophila psittaci genotypes D, F and E/B to a veterinary scientist

Two groups of five 1-day-old conventional turkeys were housed in negative pressure stables to become experimentally infected with Avian Metapneumovirus (aMPV) and Ornithobacterium rhinotracheale (ORT) at the age of 3 weeks. However, during the first 2 weeks, turkeys started to show respiratory disease characterized by rhinitis and dyspnoea. Routine bacterial and viral diagnoses remained negative. Therefore, pharyngeal swabs from the turkeys and from the veterinary scientist handling the animals were examined for the presence of Chlamydophila (C.) psittaci by using a combination of cell culture, nested PCR and ompA genotype-specific quantitative real-time PCR, as well as by serology. Results revealed simultaneous transmission of C. psittaci outer membrane protein A (ompA) genotypes D, F and E/B from infected turkeys to the veterinary scientist.     

Long-term effects of agronomic practices on the soil organic carbon sequestration in Chernozem

The study was based on data from selected long-term field trials established at the Experimental Fields of the Institute of Field and Vegetable Crops, Novi Sad (Serbia). The effect of tillage systems on SOC concentration and SOC stock was most pronounced at 0–10 cm depth. In a 0–40 cm soil layer, in a 7-year period, no-till (NT) sequestrated 863 kg SOC ha^?1 yr^?1 more compared to moldboard plow tillage (PT), while the effects of disc tillage (DT) and chisel tillage (CT) were not significantly different. Unfertilized three-crop rotation (CSW) compared to two-crop rotation (CW) enhanced SOC storage in a 0–30 cm soil layer by 151 kg C ha^?1 yr^?1 in a 56-year period. Within fertilized treatments, SOC concentration was highest under continuous corn (CC). Mineral fertilization (F) non-significantly increased the SOC stock compared to no fertilization in corn monoculture in a 32-year period. The incorporation of mineral fertilizers and harvest residues (F + HR) and mineral fertilizers and farmyard manure (F + FYM) sequestered 195 and 435 kg C ha^?1 yr^?1 more than the unfertilized plot, respectively, in a 0–30 cm soil layer, in a 35-year period. Irrigation did not significantly affect SOC sequestration.     

The attraction of cerambycids and other xylophagous beetles, potential vectors of Bursaphelenchus xylophilus, to semio-chemicals in Slovenia

The attractiveness of different semio-chemicals to potential vectors of the phytoparasitic nematode Bursaphelenchus xylophilus was investigated in conifer forests in Slovenia. From 2007 to 2009, the presence of xylophagous beetles in Pinus nigra, P. sylvestris, P. halepensis, Picea abies and Abies alba stands was assessed at eight locations. Insects were collected at 1-month intervals during the growing season using four cross vane traps per location with a collecting container with propylene glycol and attractants (ethanol+??-pinene, Pheroprax? and Gallowit?). The trapped insects represented 24 families of the order Coleoptera, and we identified 94 species. The most numerous group was the weevil subfamily Scolytinae (76.55% of all insects collected), followed by the family Cerambycidae (8.12%), and the weevil subfamily Curculioninae (1.67%). With regard to species number, the most frequent wood-borers were Cerambycidae (24 taxa), Scolytinae (12 species) and Buprestidae (8 species). The most abundant species was Spondylis buprestoides, followed by Arhopalus rusticus, Monochamus galloprovincialis and Arhopalus ferus. At all locations, the largest catch of Cerambycidae occurred in July. The most effective attractant was ethanol+??-pinene, followed by Gallowit?; the least effective attractant was Pheroprax?. Among Monochamus species, M. galloprovincialis represented 17.54%, M. sutor 0.09% and M. sartor 0.04% of the long-horned beetles collected. Monochamus individuals were most numerous in the P. nigra stand and were attracted in the greatest numbers by Gallowit?, followed by ethanol+??-pinene. The cerambycid catch was highly correlated with the catch of non-target bark beetle predators (Cleridae, Staphylinidae, Histeridae, Trogositidae, Nitidulidae, Rhizophagidae) in the traps.     

The response of phenolic compounds in grapes of the variety ‘Chardonnay’ (Vitis vinifera L.) to the infection by phytoplasma Bois noir

The study was carried out on phytoplasma susceptible grapevine variety ‘Chardonnay’ (Vitis vinifera L.). The changes in total and individual phenolics, with a focus on hydroxycinnamic acids, flavanols and flavonol contents, were studied in phytoplasma-symptomatic and non-symptomatic berries of Bois noir (BN) infected and uninfected vines. Evident responses to BN infection at veraison have been monitored in a decreased accumulation of caftaric and coutaric acids, p-coumaroyl hexose, procyanidin B1, procyanidin trimer as well as of quercetin-3-O-glucoside, quercetin-3-O-glucuronide and quercetin-3-O-xyloside. At berry softening BN infection statistically increased the content of total phenolics, hydroxycinnamic acids and flavanols, but decreased the flavonol contents, especially at phytoplasma-symptomatic berry skins. Later, at harvest, the BN infection caused an additional significant decrease of coutaric acid and p-coumaroyl pentose contents, moreover of procyanidin B1 and procyanidin dimmers (1, 2, and 3), trimer, kaempferol-3-O-glucoside and of most identified quercetins, except of quercetin-3-O-xyloside. At harvest, non-symptomatic berries from infected plants showed similar dynamics in the total phenolic content compared to berry skins from uninfected plants, but in total flavanols and flavonols content similarity to those symptomatic was observed. The latter decreases grape quality and its antioxidant potential. The Bois noir disease showed specific, local and growth-phase-induced responses regarding the content of phenolics in berry skins, where in particular the differences between phytoplasma-symptomatic and non-symptomatic grapes have to be underlined.     

Screening of medicinal and ornamental plants for insecticidal and growth regulating activity

Extracts of 121 medicinal and ornamental plants were screened for insecticidal and growth regulating activity to milkweed bug, Oncopeltus fasciatus Dallas. The most effective extracts stemmed from Inula helenium L., Rumex crispus L., R. acetosa L., Asarum europaeum L., and Calendula officinalis L. All these extracts exerted growth inhibiting activities and moderate or low acute toxicity. Most promising were extracts of dried roots of I. helenium. Besides a moderate chronic toxicity which reduced the fitness of the milkweed bug, the treatment produced overaged nymphs, supernumerary nymphs, disturbances of the moulting process, morphological defects, delay of adult maturation and reduction of fecundity. In addition, I. helenium extracts had a strong antifeedant effect when topically applied and very strong repellent effect when applied to the food (peeled sunflower kernels). It is obvious that the extract contains several active constituents. Such a cocktail may reduce the threat of rapid resistance development.