Predicting field performance using seedling quality assessment

Seedling quality is defined as fitness for purpose. Attributes for assessing seedling quality are grouped in material attributes that can be rapidly assessed by any number of direct or indirect methods, and performance attributes that are assessed by subjecting whole seedlings to certain environmental regimes and evaluating their growth response. Material attributes comprising morphology, bud dormancy, water relations and nutrition and performance attributes comprising frost hardiness, vigour and root growth potential are discussed with regard to relevance for predicting field performance. Measurement techniques and relevance in assessing seedling quality are presented for different physiological attributes: electrolyte leakage, enzymatic activity, water potential, water conductance, mineral nutrition, food reserves, mitotic index, gas exchange, chlorophyll content, plant growth regulators, stress-induced volatile emission, and nuclear magnetic resonance. Methods with future potential in improving the prediction of field performance are identified and discussed. The methods presented in this respect are chlorophyll fluorescence, infrared thermography, machine vision systems, integrated approaches and ecophysiological evaluations.     

Medically used radionuclides in sewage sludge

The concentration of medically used radionuclides has been studied in sludge from the sewage treatment plant serving the borough of Malmo. In this area all nuclear medicine procedures are carried out in one hospital and almost all patients live in the borough. Therefore, the input of medically used radionuclides into the sewage system can be estimated with good accuracy. Samples of digested sludge have been taken once or twice a week during half a year. Iodine-131 (physical half life (T) = R.05 d) was detected in all samples. The ¹³¹I-activity concentration due to medical use varied between (0.03±0.01) and (0.12±0.02) nCi kg^?1. The ratio between the total output of ¹³¹I via the sludge and an adherent input of the radionuclide into the sewage system was determined to (2.6 ± 0.6) × 10^?3, which is equivalent to a ratio of (2 ± 1) × 10^?2 for stable I. Occasionally measurable activities of ¹⁹⁸Au (T=2.7 d) and ²⁰¹T1(T=3.l d) have been found. The radioactivity concentration of medically used radionuclides in the sludge is low and constitutes no health problems for the persons involved. The sludge however has proved to be a very sensitive and suitable integrator of radioactive material released from a large urban area.     

Long-Term Base Cation Balances of Forest Mineral Soils in Finland

Long-term base cation balances (Ca, Mg and K) for forest mineral soils in Finland were calculated with mass balance methods. The aim of the study was to identify the areas in which weathering and base cation deposition do not support leaching and uptake of base cations by vegetation. The effect of stem harvesting and whole-tree harvesting on the base cation balances was studied and preliminary calculations were made about the amounts of ash needed for compensation of the potential base cation depletion. The effect of sulphur emission reduction till 2010 was also considered. The study demonstrated that there would be depletion of base cations in forest mineral soils in southern, central and northeastern Finland (40–50% of the grids) in the long term if whole-tree harvesting would be practised. Theoretical calculations showed that ash application would be most useful in those areas to compensate the base cation depletion. If stem harvesting is practised, only small areas (20%) in southwestern and southeastern Finland and northeastern Lapland would show depletion of base cations in the long term.     

In silico prediction of Gallibacterium anatis pan-immunogens

The Gram-negative bacterium Gallibacterium anatis is a major cause of salpingitis and peritonitis in commercial egg-layers, leading to reduced egg production and increased mortality. Unfortunately, widespread multidrug resistance and antigenic diversity makes it difficult to control infections and novel prevention strategies are urgently needed. In this study, a pan-genomic reverse vaccinology (RV) approach was used to identify potential vaccine candidates. Firstly, the genomes of 10 selected Gallibacterium strains were analyzed and proteins selected on the following criteria; predicted surface-exposure or secretion, none or one transmembrane helix (TMH), and presence in six or more of the 10 genomes. In total, 42 proteins were selected. The genes encoding 27 of these proteins were successfully cloned in Escherichia coli and the proteins expressed and purified. To reduce the number of vaccine candidates for in vivo testing, each of the purified recombinant proteins was screened by ELISA for their ability to elicit a significant serological response with serum from chickens that had been infected with G. anatis. Additionally, an in silico prediction of the protective potential was carried out based on a protein property prediction method. Of the 27 proteins, two novel putative immunogens were identified; Gab_1309 and Gab_2312. Moreover, three previously characterized virulence factors; GtxA, FlfA and Gab_2156, were identified. Thus, by combining the pan-genomic RV approach with subsequent in vitro and in silico screening, we have narrowed down the pan-proteome of G. anatis to five vaccine candidates. Importantly, preliminary immunization trials indicated an in vivo protective potential of GtxA-N, FlfA and Gab_1309.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-014-0080-0) contains supplementary material, which is available to authorized users.     

Abrasions and lameness in piglets born in different farrowing systems with different types of floor

Background

The quality of the floor is essential to the welfare of piglets as abrasions often are recorded in newborn piglets, and such lesions may lead to lameness. Apart from animal suffering, lameness contributes to losses in form of dead piglets, decreased growth, and increased use of antibiotics and manual labour.

Methods

In a herd with three different farrowing systems, 37 litters (390 piglets) were studied until the age of 3 weeks with respect to presence of skin wounds and abrasions. Lameness was registered until the age of 7 weeks. Eight lame piglets were sacrificed before medical treatment and subjected to necropsy including histopathological and microbiological examinations. Isolates of streptococci, staphylococci and E. coli were tested with respect to antimicrobial resistance. Mastitis was observed in ten sows.

Results

The most severe abrasions at carpus and soles were seen in the system with a new solid concrete floor with a slatted floor over the dunging area. The lowest magnitude was observed in the deep litter system with peat. Sole bruising was more common in the systems with concrete floor compared to the deep litter system with peat, and the differce in prevalence was significant at all examination days. The lesions decreased with time and about 75% of the treatments for lameness were performed during the first three weeks of life. The overall prevalence of lameness was highest in the system with new solid concrete floor with a slatted floor over the dunging area (9.4%) followed by the old solid concrete floor (7.5%). A lower (p < 0.05) prevalence was seen in the deep litters system with peat (3.3%). No significant relationship between mastitis and abrasions or lameness in the offspring was observed.

Conclusion

There were large differences in the prevalence of abrasions and lameness between the floor types. The deep litter system with peat provided a soft and good floor for piglets. The overall prevalence of lameness was only diagnosed in every fourth litter in that system compared to in every second litter in the systems with concrete floor. In contrast, the incidence of mastitis in the sows during the first week after farrowing was higher than in the systems with concrete floor.     

Effect of air temperature, rain and drought on hot water weed control

The influence of rain and drought before, and air temperature during, weed control with hot water was studied in laboratory experiments on the test weed Sinapis alba (white mustard). The plants were grown in a greenhouse and treated outdoors. There was no difference in weed control effect when S. alba plants at the four‐leaf stage were treated at the air temperatures 7°C and 18^°C. The effective energy dose for a 90% fresh weight reduction was 465 kJ m^?2 for both air temperatures. Weed control of S. alba at the four‐ to six‐leaf stage in rainfall above the rainwater run‐off level increased the required effective energy dose by 20% (i.e. 120 kJ m^?2) compared with dry plants. A short period of drought just before treatment on S. alba at the two‐ to four‐leaf stage increased the plant fresh weight reduction, which was 22% at low energy dose (190 kJ m^?2) and 44% at high energy dose (360 kJ m^?2). Hot water weed control should thus be carried out when the plants are drought stressed and avoided when the plants are wet. The air temperature seems to be of little importance in the range 7–18^°C.     

Effect of short chain fatty acids infused intraileally on interdigestive exocrine pancreatic secretions in growing pigs

The effect of intraileally infused short chain fatty acids (SCFA) and saline as control on the exocrine pancreatic secretions during the interdigestive phase was studied using three 8-weeks-old piglets. Pigs were surgically fitted with a pancreatic duct catheter, re-entrant duodenal T-cannula for collection and subsequent return of pancreatic juice, and with an infusion T-cannula at the distal ileum. Saline as control, 5.0 and 10.0 mm butyrate, 7.5 and 15.0 mm propionate and 85.0 and 170.0 mm acetate were infused at 2 ml/kg body weight (BW) for 30 min into the ileum of overnight fasted piglets via ileal T-cannula. The calculated volume of infusates was administrated in five equal bolus at 6 min intervals over a period of 30 min. The pancreatic juice was collected 60 and 30 min before and 30, 60, 90 and 120 min after the start of infusion. The trypsin (p = 0.07, p > 0.15 respectively) and protein (p > 0.15, p = 0.05 respectively) outputs immediately decreased after the infusion of acetate at the dose of 85.0 and 170.0 mm, respectively, whereas pancreatic juice outflow (p > 0.15) was not significantly affected when compared with levels 30 min before infusion. After the infusion of butyrate at the dose of 5.0 mm, trypsin (p = 0.01) and protein (p = 0.12) outputs increased immediately whereas pancreatic juice outflow was not affected (p > 0.15) in comparison with levels 30 min before infusion. No significant differences were observed after infusion of butyrate at the dose of 10 mm for the pancreatic juice outflow, trypsin and protein outputs when compared with the level before infusion, although these values were numerically lower immediately after the infusion. The pancreatic juice outflow increased (p = 0.03) after the infusion of propionate at the dose of 7.5 mm and decreased (p = 0.005) immediately after the infusion of propionate at the dose of 15.0 mm when compared with the levels 30 min before the infusions. After the infusion of propionate at the dose of 7.5 or 15.0 mm for the output of protein and trypsin, no significant differences (p > 0.15) were observed when compared with levels 30 min before infusion. In summary, the intraileal infusion of SCFA at different doses exerts a short-term and moderate effect on the interdigestive exocrine pancreatic secretions in pigs.     

Potential application of serological tests on fluids from carcasses: detection of antibodies against Toxoplasma gondii and Sarcoptes scabiei in red foxes (Vulpes vulpes)

Background

Serological surveys for disease investigation of wild animal populations require obtaining blood samples for analysis, which has logistic, ethic and economic difficulties. Applying serological test to fluids collected from dead animals is an alternative. The aim of this study was to assess if antibodies could be detected in two types of fluids collected from 56 carcasses of red foxes (Vulpes vulpes): pleural fluid and lung extract.

Findings

In 22 (39%) foxes antibodies against Sarcoptes scabiei were detected in both fluid types by ELISA and Western blot. In 46 (82%) foxes, antibodies against Toxoplasma gondii were detected in pleural fluid and in 41 (73%) in lung extract applying a Toxo-screen test (DAT). Antibodies were still detectable in the same fluids kept at room temperature for 28 days, although in fewer foxes (16 and 14 foxes tested for T. gondii in lung extract and pleural fluid respectively; and 1 and 4 tested for S. scabiei in lung extract and pleural fluid respectively.

Conclusions

These results indicate the potential utility of using fluids from carcasses for antibody screening of wild animals at the population level.     

Pinus contorta growth in northern Sweden as affected by soil scarification

The aim of this study was to quantify the effects of different soil scarification methods on tree growth. Soil scarification influenced stem volume and stem biomass yield of lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.) in a 17-year-old field trial in boreal Sweden. Soil scarification (disc trenching, mounding and ploughing) resulted in an average stem volume yield of 3.1 and 34.2 m³ ha^–1 on the poor and intermediate sites, respectively, while corresponding values for no soil scarification were 0.9 and 16.7 m³ ha^–1. In comparison to no scarification, ploughing increased volume yields by 500% on the poor site and by 200% on the intermediate sites. The ranking according to stem volume yield was ploughing > disc trenching = mounding no soil scarification. Averaged over the two sites, the mean annual increment of stem biomass was 219% and 145% higher (in d.w., 0.26 kg and 0.34 kg per sample tree) after ploughing compared with no soil scarification, for the average and dominant sample trees, respectively. Although not significant, the increased growth rate after soil scarification decreased the average stem basic wood density of the sample trees with 1.6% and 5.3%, at the poor and intermediate sites, respectively. In conclusion, soil scarification significantly increased the 17-year stem volume yield compared with no scarification. The results also indicate that the difference in stem biomass yield between ploughing and the other methods, especially no soil scarification, will increase even more in the near future.