Quantitative trait loci conferring blast resistance in hexaploid wheat at adult plant stage

Blast disease, caused by the Magnaporthe oryzae Triticum pathotype (MoT), is a major concern for wheat production in tropical and subtropical regions. The most destructive symptoms occur in wheat spikes. Infected spikes become bleached due to partial or total sterility, producing small and wrinkled grains. High disease pressure of the disease results in significant yield losses. This study aimed to identify wheat quantitative trait loci (QTLs) conferring resistance to blast disease at the heading stage. A doubled-haploid population was developed from the cross between BRS 209 (susceptible) and CBFusarium ENT014 (resistant, carrying the 2NS translocation). A linkage map was constructed containing 5,381 molecular markers and the inclusive composite interval mapping method was employed for QTL detection. Four QTLs were mapped in response to two MoT isolates. The major QTL identified on the 2AS chromosome explained an average of 84.0% of the phenotypic variation for spike bleaching at 9 days postinoculation and reinforces the potency of the 2NS translocation. Recombination between the distal region of chromosome 2AS and the 2NS marker was found. These results could explain why some lines carrying the VENTRIUP/LN2 marker have a variable reaction to the disease. QTLs on 5B and 7B chromosomes were also identified. Two mechanisms of resistance were hypothesized: the hypersensitive response and resistance to colonization of host tissues. The KASP markers thus developed and simple sequence repeats (SSRs) allocated in QTL regions can be used in the future for the development of wheat blast-resistant cultivars.     

Polyphenols in Acacia mangium and Acacia auriculiformis heartwood with reference to heart rot susceptibility

The heartwood of Acacia mangium is vulnerable to heart rot and this is the first study to investigate the role of heartwood extractives in its susceptibility. Acacia auriculiformis was compared with A. mangium because it is rarely associated with heart rot. The heartwood extracts of both species were dominated by three flavonoids (2,3-trans-3,4′,7,8-tetrahydroxyflavanone, teracacidin, and 4′,7,8,-trihydroxyflavanone), which were purified and identified by nuclear magnetic resonance spectroscopy. The latter compound has not been previously reported in A. mangium and evidence for melacacidin is also newly reported. The mass spectrometric (MS) behavior of these compounds is given, for example teracacidin does not form molecular ions by either electrospray ionization or atmospheric-pressure chemical ionization. The nature of Acacia tannins was compared to quebracho tannin (composed of profisetinidins) using oxidative cleavage to enable MS detection but a negative reaction was obtained for both, which suggests the Acacia tannins may also be of the 5-deoxy proanthocyanidin type. The concentration of flavanones was less when A. mangium heartwood was decayed but the amount of proanthocyanidins was only slightly reduced and therefore these compounds may be more resistant to degradation by heart rot fungi. We found that the total phenol content of A. auriculiformis was about fivefold that of A. mangium, and, while preliminary, this provides evidence for a role played by phenolic extractives in heart rot resistance of these Acacia species.     

Hygiene management in newborn individually housed dairy calves focusing on housing and feeding practices

In calf rearing, the first weeks of life are critical and associated with the highest mortality due to enteric and respiratory diseases. A well-implemented hygiene management can help to protect calves’ health preventively by reducing the load of pathogenic bacteria and interrupting infection chains. The aim of this study was to identify deficiencies in hygiene management of individually housed dairy calves by surveying current practice and examining feeding and housing equipment with different hygiene indicators. On 11 farms, different locations in 2 pens or hutches for individual calf rearing prepared for restocking and 2 feeding buckets per farm, including the inner and outer surfaces of artificial teats, were visually scored for cleanliness and sampled with swabs (housing equipment: n = 167; feeding equipment: n = 120). The sanitation of floors was tested with sock samples (n = 41). A total of 328 samples were analyzed for adenosine triphosphate (ATP) and protein residues, aerobic total viable count (TVC), total coliform count (TCC), Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum β-lactamase-producing bacteria (ESBL), and Salmonella spp. After evaluation of these results, the farmers were informed about the findings and trained on improvement in hygiene management personally. The sampling was repeated after 1 year to detect possible changes in hygiene management. The highest bacterial loads (TVC, TCC, and E. coli) were observed in feeding equipment, especially the inner teat of milk feeding buckets. Environmental samples, primarily the sidewalls and back walls of tested pens and hutches, exhibited the lowest bacterial counts and ATP and protein residues. All samples were negative for MRSA and Salmonella spp. In 10.5% of all samples, ESBL was detected, and in 6.8%, ESBL E. coli was detected, predominately in sock samples, followed by feeding equipment samples. Training in hygiene management showed only limited effects. In conclusion, there is still great potential to improve the implementation of hygiene measures in individual calf housing. In particular, more attention should be paid to the cleaning of feeding buckets and artificial teats, as this is a simple means of interrupting the possible spread of pathogens among calves.     

Effects of crude protein and sodium intake on water turnover in cats fed extruded diets

The comprehension of strategies to increase urine production may be important, especially in kibble diets to prevent urolithiasis in cats. The effects of increasing amounts of crude protein (CP) and sodium on the water turnover of cats were evaluated using the water balance (WB) method and the deuterium dilution technique. The study followed a randomized block design, with three blocks of eight cats, two cats per food type in each block, and six cats per food. Four extruded diets with different amounts of CP and sodium were evaluated (on DM basis): 28% CP and 0.58% sodium; 39% CP and 0.64% sodium; 52% CP and 0.76% sodium; and 64% CP and 0.87% sodium. Cats were individually housed in cages for 8 days to measure WB, urea excretion, and faecal and urine characteristics. Deuterium oxide was used to evaluate water turnover, and during the period cats were housed in a collective cattery. The data were analysed by an F test, and the means were compared by polynomial contrasts. The ɑ level of significance was set at 0.05. The methods were compared by Pearson correlation, and Bland and Altman analysis. The increase in the CP content elevated linearly the renal excretion of urea (p < .001), and, together with the higher sodium intake, elevated the renal solute load, which resulted in a linear increase in urine production and water intake (p < .01). The urine density, metabolic water, and faecal and insensible water losses did not differ (p > .05). The water flux increased linearly when using the deuterium method (p < .001), but the obtained values were 20.85 ± 11.11 ml/cat/day higher than those verified using the WB method (p = .001). Higher CP and sodium amounts in dry diets increased the urine production and water consumption of cats, and this can be explored as a possible option to increase urination.     

Comparison of gluteus medius muscle activity in Haflinger and Noriker horses with polysaccharide storage myopathy

Type 1 polysaccharide storage myopathy caused by genetic mutation in the glycogen synthase 1 gene is present in many breeds including the Noriker and Haflinger horses. In humans, EMG has already been used to document changes in the muscle activity patterns of patients affected by human glycogen storage disorders. Therefore, the aim of the present study was to describe gluteus muscle activity with surface electromyography (sEMG) in Haflinger and Noriker horses with known GYS1 mutation status during walk and trot. Thirty-two horses (11 Haflinger and 21 Noriker horses) with homozygous non-affected (GG), heterozygous affected (GA) and homozygous affected (AA) status of GYS1 mutation without overt clinical signs of any myopathy were selected for the current study. Using surface electromyography gluteus medius muscle activity at walk and at trot was measured, and muscle activity was described in relation to the maximum observed value at the same sensor and the same gait. In order to further describe the signals in detail comprising both frequencies and amplitudes, the crossings through the baseline and the 25, 50 and 75 percentile lines were determined. The result of the relative muscle activity did not show a consistent difference between affected and non-affected horses. Genetically affected (GA and AA) horses showed significantly less density of muscle activity for both gaits and horse breeds except for the crossings per second at the baseline and 75 percentile at walk in the Haflinger horses and 75 percentile at trot in the Noriker horses. The medians of all calculated density values were significantly lower in the GA Haflingers compared to the GG Haflingers (p = 0.012) and also in the AA Norikers compared to the GG Norikers (p = 0.011). Results indicate that the GYS1 mutation reduces the number of functional muscle fibres detected by sEMG measurements even in the absence of overt clinical signs.     

Concentration effects in myoglobin-catalyzed peroxidation of linoleate

The concentration of the free fatty acid anion linoleate was found to be important for the pro-oxidative activity of metmyoglobin, MbFe(III), and for mixtures of metmyoglobin and hydrogen peroxide, MbFe(III)/H(2)O(2), to yield perferrylmyoglobin, (*)MbFe(IV)=O, whereas for ferrylmyoglobin, MbFe(IV)=O, no concentration effect was noted as studied in linoleate emulsions (pH 7.4 and 25 degrees C). Determination of conjugated dienes using second-derivative absorption spectroscopy, changes in Soret band absorbance, and spin-trapping ESR spectroscopy with alpha-(4-pyridyl-1-oxide)-N-tert-butyl nitrone (POBN) as the spin trap were used to evaluate the pro-oxidative activity of myoglobins. At a linoleate (LA)/heme protein (HP) ratio of 100, no MbFe(III)-induced linoleate peroxidation was observed, as MbFe(III) was converted to its non-pro-oxidative low-spin derivative, hemichrome, independently of the presence of H(2)O(2). At higher LA/HP ratios, linoleate peroxidation was initiated by the addition of MbFe(III), both in the presence and in the absence of H(2)O(2). This proceeded with denaturation of MbFe(III), as followed by changes in Soret absorption band, which most probably release or expose the heme group to the environment and thereby permit hematin-induced lipid peroxidation. The obtained results show that the mechanism by which MbFe(IV)=O initiates linoleate peroxidation is different from MbFe(III)- and MbFe(III)/H(2)O(2)-initiated linoleate peroxidation. The shift in mechanism between heme protein cleavage of lipid hydroperoxides and hematin-induced lipid peroxidation is discussed in relation to oxidative progress in biological systems and muscle-based foods.     

Myoglobin-induced lipid oxidation. A review

An overview of myoglobin-initiated lipid oxidation in simple model systems, muscle, and muscle-based foods is presented. The potential role of myoglobin spin and redox states in initiating lipid oxidation is reviewed. Proposed mechanisms for myoglobin-initiated lipid oxidation in muscle tissue (pH 7.4) and meat (pH 5.5) are evaluated with the purpose of putting forward general mechanisms explaining present observations regarding the catalytic events.     

UV treatment of fishmeal: a method to remove dioxins?

This study evaluates the use of UV on contaminated fishmeal and photodegradation of dioxins. Fishmeal samples were placed under UVA or UVB light for 2, 5, and 10 days. Subsequently, analysis of amino acid content, lipid oxidation marker, ethoxyquin content, dioxin, and polychlorinated biphenyl (PCB) profiling was carried out. Exposure of fishmeal for 5 days to UVB light resulted in the degradation of approximately 70% of the dioxin content, while UVA had little effect, only resulting in the degradation of 10% of the dioxin content. UVB did not affect the protein and amino acid content of fishmeal; however, lipid oxidation was triggered. Addition of ethoxyquin prevented oxidation but simultaneously slowed dioxin breakdown. Increasing UVB intensity resulted in a more efficient dioxin degradation of 90%. Exposure of fishmeal to UVB also resulted in an increase in PCBs. UVB light is shown to photodegrade dioxin in fishmeal, indicating the needs to further investigation of methods for application at industrial scale.     

Soil incubation study showed biogas digestate to cause higher and more variable short‐term N2O and N2 fluxes than mineral‐N

Today, a large share of mineral fertilizer is substituted by biogas digestates. Biogas digestates are known to promote N₂O production, compared to mineral fertilizer. In particular, the initial phase following fertilizer application is crucial for the N gas release as N₂O and also N₂. However, this period impact has been rarely investigated, especially not across various field sites. Thus, undisturbed soil cores from two fertilizer types (biogas digestate vs. mineral fertilizer) at five sites with different site characteristics were investigated in a short‐term laboratory experiment under N₂‐free helium–oxygen incubation atmosphere. Across sites, biogas digestate soil cores showed significantly higher absolute N₂O fluxes compared to mineral fertilizer soil cores, even though this effect was dominated by samples from one site (Dornburg with the highest biogas digestate fertilization rate). Also relative N₂O fluxes showed a similar tendency. On average, absolute and relative N₂ fluxes differed between the two fertilizer types, while N₂ fluxes were highest at the Dornburg site. A N₂O/(N₂O+N₂) ratio of denitrification below or equal to 0.5 clearly highlighted the importance of N₂O reduction to N₂ for three of five the biogas digestate soil cores. Soil characteristics like bulk density and water‐filled pore space as proxies for gas diffusivity in soil, as well as N availability ( ${\mathrm{NO}}_3^{-}$, ${\mathrm{NH}}_4^{+}$), significantly affected the N₂O and N₂ fluxes from the biogas digestate soil cores. While this study presents data on short‐term N₂O and N₂ fluxes, there is a need for further studies in order to investigate the dynamics, the duration of the observed effects and their significance at the field scale.