Effects of different soil treatments on growth and net nitrogen uptake of newly planted Picea abies (L.) Karst. seedlings

Five soil treatments in a 4-year-old clearcut in southern Sweden affected biomass increase and net nitrogen uptake by planted Norway spruce (Picea abies (L.) Karst.) seedlings through their on net mineralisation and root growth. The patch soil treatments studied were: (i) soil inversion in an old clearcut; (ii) mineral soil from the clearcut remaining, (iii) mineral soil from the clearcut with fertiliser application during the first season; (iv) mineral soil from a nearby uncut forest replacing the clearcut mineral soil; and (v) an untreated control. Growth increased in seedlings in treatments (i) and (iii), but growth in soil treatments with humus removal was not better than that of seedlings in untreated soil. High N uptake early in the first growing season resulted in increased growth during this season in contrast to late N uptake that resulted in a high N concentration in the seedlings after the first growing season. This in turn led to a high growth rate during the next growing season. Generally, both root growth and net N mineralisation were positively correlated to N uptake in the soil treatments. Therefore, a combination of low net N mineralisation and poor root growth as a result of high soil density appears to explain the low N uptake in seedlings in undisturbed soil. The importance of competition with field vegetation for N and water was not clear. Net mineralisation was larger in soil treatments where the humus layer was retained than where it was removed. Net N mineralisation in soil from old clearcuts was the same as in soil from fresh clearcuts.     

A new microassay for antifeedants in<Emphasis Type="Italic"> Hylobius</Emphasis> pine weevils (Coleoptera)

A micro-feeding assay was developed for testing small amounts of synthetics and extracts as antifeedants for Hylobius pine weevils. We devised a simple setup consisting of 5×5-mm pieces of thin layer chromatography cellulose plates used in pairs for a bioassay involving choice. After application of 1.5 l solutions and evaporation of the solvent, each plate received a 5 l aliquot of 1 M sucrose as a feeding stimulant. The test period was 4 h at 25 °C with 6 days of starvation before the test, compared to just the 1 day sufficient for twig tests. Deprivation of water for 1 day at 65% RH before the test was critical because it increased feeding but not mortality. The combination of starvation and thirst reduced the relative variance (coefficient of variation) to below 50%. There was a good correlation of antifeedant activity in the microassay with the activity in a standard twig test. The microassay needs only several mg for a test series, whereas the twig test needs grams.     

Health of farmed fish: its relation to fish welfare and its utility as welfare indicator

This brief review focuses on health and biological function as cornerstones of fish welfare. From the function-based point of view, good welfare is reflected in the ability of the animal to cope with infectious and non-infectious stressors, thereby maintaining homeostasis and good health, whereas stressful husbandry conditions and protracted suffering will lead to the loss of the coping ability and, thus, to impaired health. In the first part of the review, the physiological processes through which stressful husbandry conditions modulate health of farmed fish are examined. If fish are subjected to unfavourable husbandry conditions, the resulting disruption of internal homeostasis necessitates energy-demanding physiological adjustments (allostasis/acclimation). The ensuing energy drain leads to trade-offs with other energy-demanding processes such as the functioning of the primary epithelial barriers (gut, skin, gills) and the immune system. Understanding of the relation between husbandry conditions, allostatic responses and fish health provides the basis for the second theme developed in this review, the potential use of biological function and health parameters as operational welfare indicators (OWIs). Advantages of function- and health-related parameters are that they are relatively straightforward to recognize and to measure and are routinely monitored in most aquaculture units, thereby providing feasible tools to assess fish welfare under practical farming conditions. As the efforts to improve fish welfare and environmental sustainability lead to increasingly diverse solutions, in particular integrated production, it is imperative that we have objective OWIs to compare with other production forms, such as high-density aquaculture. However, to receive the necessary acceptance for legislation, more robust scientific backing of the health- and function-related OWIs is urgently needed.     

Use efficiency of nitrogen from biodigested plant material by ryegrass

Apparent nitrogen‐use efficiency of the applied mineral N (NUE_min) in effluent from biodigested plant material (BE; C : N_org ratio 14:1; mineral N–to–total N ratio 0.5:1) and a nitrate‐based inorganic fertilizer (IF), both applied at two rates was investigated in a six‐month pot experiment with Italian ryegrass (Lolium multiflorum Lam.). Dry‐matter (DM) production was 7% lower and total amount of N in aboveground biomass was 8% lower in BE than in IF at 40 d after sowing (DAS), equal at 81 DAS, and higher in BE than in IF at 136 and 172 DAS. NUE_min calculated on the basis of accumulated N in aboveground biomass of ryegrass in fertilized treatments compared to a control without N application was significantly lower in BE than in IF up to the third cut (136 DAS). Total NUE_min, total N recovery, and amount of foliage DM were similar for both fertilizers at the end of the experiment. Root biomass, total DM produced including roots and stubble, the fraction of root N to total plant N, and soil mineral N at 172 DAS were higher for BE than for IF. Mineral N applied with biogas‐reactor effluent was almost as effective as the nitrate‐based mineral fertilizer used for comparison. Within the six‐month experimental period net N mineralization, estimated at 12% of organic N in effluent, was not substantial. Hence, the organic compounds in the effluent were relatively recalcitrant.     

Open geospatial technology standards and their potential in plant pest risk management—GPS-enabled mobile phones utilising open geospatial technology standards Web Feature Service Transactions support the fighting of fire blight in Norway

The threat posed by invasive alien species to global crop production and biodiversity is recognized as one of the major drivers of global change today. Here we report on a successful implementation and operational use of new technology to support risk- and crisis management in the case of fighting an invasive plant disease. The open geospatial standards Web Feature Service Transaction (WFS-T) was implemented in software for GPS-enabled mobile phones communicating with a GeoServer backend in order to track down and eradicate disease outbreaks and susceptible host plants. This new technology offering georeferenced events online from field provides new possibilities for real time action in risk and crisis management.     

A COMPUTED TOMOGRAPHIC STUDY OF VOLUME AND X-RAY ATTENUATION OF THE LUNGS OF BEAGLES IN VARIOUS BODY POSITIONS

The influence of body position on volume and x-ray attenuation of the lungs of three Beagles was investigated with computed tomography. In left and right lateral recumbency, the dependent lung had decreased volume and increased x-ray attenuation compared with ventral recumbency. Volume and x-ray attenuation of the nondependent lung, however, were unchanged. In dorsal recumbency, there was a vertical gradient of x-ray attenuation being increased dorsally and decreased ventrally compared with ventral recumbency where regional differences in x-ray attenuation were not found. Results indicate a risk of overlooking a mass in the dependent pulmonary parenchyma of dogs in lateral and dorsal recumbency. Regional differences in x-ray attenuation of the lungs of dogs can be avoided if the radiographs are obtained with the dog in ventral recumbency.     

Toxoplasma Gondii in Swine in South-Eastern Norway

A total of 407 swine bred in south-eastern Norway have been tested for the presence of Toxoplasma gondii antibodies in serum by use of the dye-test, and diaphragm muscle from all sero-positive and some sero-negative swine has been tested for the presence of mouse-infective cysts.The prevalence of antibodies was as low as 10.1 %. The prevalence increased with the weight of the swine, but apparently with a decline after passing a weight of 140 kg. Only dye-test titres up to 50 were found. The prevalence of dye-test positive swine was higher in small herds (< 300 swine p.a.) than in larger ones (> 300 swine p.a.). The prevalence of herds with dye-test positive swine in the region surrounding the Oslo-fjord was higher in the coastal than in the inland zone. The incidence of infection was the same during the summer-autumn period as during the winter-spring period. Toxoplasma was recovered from the diaphragm muscle of about % of the dyeπtest positive swine. Parasites were isolated from some pigs with a dye-test titre of 4, and from all the pigs with a titre of 50. Toxoplasma was not isolated from dye-test negative swine. The epidemiological and food-hygienic significance of porcine toxoplasmosis in Norway is discussed according to the present results.     

Serological Investigations of Leptospiral Deoxyribonucleases

Enzymoserological comparison of a selection of leptospira strains tested with sera from rabbits immunized with unpurified DNase of Leptospira interrogans, serotype canicola, indicates the production of DNase of serologically very similar properties by the serotypes canicola, autumnalis, icterohemorrhagiae and pomona. The DNase produced by serotype hyos was serologically different from the others, while the serotypes grippotyphosa and bataviae did not produce DNases at all. The method used made it possible to differentiate between leptospiral DNase and normally occurring DNases in the serum samples. Neither leptospira DNase nor specific leptospira-DNase-antibodies could be detected in dog sera with high agglutinationlysis titres after natural infection.     

Experimental Encephalitozoonosis in the Blue Fox: Clinical and Serological Examinations of Affected Pups

Two groups of blue fox pups about 1½— 2 and 2½—3 months old, respectively, suffering from experimental encephalitozoonosis, were examined clinically and serologically. Antibodies to Encephalitozoon cuniouli were detected in all pups, the titres varying within the range 10–12,800. In addition to unspecific signs of disease the pups showed various neurological disturbances including ataxia, posterior weakness, lameness and circling behaviour, terminaiting in recumbency, paralysis or convulsions. Reduced sight or blindness was observed occasionally. Some of the pups appeared thirsty. Haematological examinations revealed pronounced leukocytosis without any conspicuous shift within the various groups of leukocytes. Biochemical examinations of serum showed significant elevated values of urea nitrogen, creatinine, and magnesium concentrations, reflecting renal dysfunction. Alanine aminotransferase was found significantly depressed in both groups. Raised levels of total protein were demonstrated due to pronounced hyperglobulinaemia. This finding, together with the common occurrence of generalized polyarteritis nodosa and proliferations of plasma cells in clinically affected pups, is probably a result of autoimmune disturbances initiated directly or indirectly by the protozoan infection.     

Associations between the time of conception and the shape of the lactation curve in early lactation in Norwegian dairy cattle

Background

This study was carried out to determine if an association exists between the shape of the lactation curve before it is influenced by the event of conception and the time from calving to conception in Norwegian dairy cattle. Lactation curves of Norwegian Red cows during 5 to 42 days in milk (DIM) were compared between cows conceiving between 43 and 93 DIM and cows conceiving after 93 DIM.

Methods

Data from 23,049 cows, represented by one lactation each, with 219,538 monthly test days were extracted from the Norwegian Dairy Herd Recording System, which represents 97% of all Norwegian dairy cows. Besides veterinary treatments, these records also included information on daily milk yield at monthly test days. The data were stratified by parity groups (1, 2, and 3 and higher) and time to conception periods (43-93 DIM and >93 DIM). The sample was selected using the following selection criteria: conception later than 42 DIM, calving season July to September, no records of veterinary treatment and the level of energy fed as concentrates between 8.69 and 12.83 MJ. The shape of the lactation curves were parameterized using a modified Wilmink-model in a mixed model analysis. Differences in the parameters of the lactation curves with different conception times were evaluated using confidence intervals.

Results

Lactation curves characterized by a low intercept and a steep ascending slope and a steep descending slope were associated with early conception across all parities. The peak milk yield was not associated with time of conception.

Conclusions

A practical application of the study results is the use of the shape of the lactation curve in future herd management. Groups of cows with impaired reproductive performance may be identified due to an unfavorable shape of the lactation curve. Monitoring lactation curves and adjusting the feeding strategy to adjust yield therefore may be useful for the improvement of reproductive performance at herd level.