Pathology of Trichuris suis infection in pigs fed an inulin- and a non-inulin-containing diet

Pathology of the colon in pigs infected with Trichuris suis and fed an inulin and a non-inulin containing diet was studied to investigate the inflammatory response induced and the influence of inulin on this. Twenty-nine pigs were allocated into four groups (N-7, I-7, N-9 and N/I-9). Groups N-7, N-9 and N/I-9 were given a diet with non-fermentable carbohydrates, and group I-7 was fed a diet including fermentable carbohydrates (inulin). After 2 weeks, all pigs were inoculated with 2000 T. suis eggs. Seven weeks post-infection (p.i.), groups N-7 and I-7 were killed and group N/I-9 changed to inulin diet to study the influence of inulin on already established T. suis. Nine weeks p.i., groups N-9 and N/I-9 were killed. Trichuris suis were collected from the colon for enumeration. Tissues from the colon of each pig were taken for histological and immunohistochemical quantitative and semi-quantitative evaluations of heterophils, eosinophils, mast cells, IgA(+), IgG(+), IgM(+) and CD3(+) cells. The findings were compared with tissues from seven uninfected pigs of the same age. Pigs fed inulin had significantly fewer worms compared with pigs on the non-fermentable carbohydrate diet. The number of inflammatory cells in the colonic mucosa was increased in all T. suis-infected pigs compared with uninfected controls. The numbers of eosinophils, mast cells, IgA(+), IgG(+) and CD3(+) cells were significantly lower in pigs fed inulin than pigs fed non-fermentable carbohydrate. Whether this is a direct effect of inulin or a secondary effect due to the lower parasitic burden in inulin fed pigs is not known.     

Intra- and inter-observer agreement of a protocol for clinical examination of dairy cows

In 2004,five veterinarians examined 283 dairy cows from four Danish dairy herds and independently assigned scores for the clinical signs lameness, hock lesions and other cutaneous lesions to each cow using a clinical protocol. We evaluated the inter-observer and the intra-observer agreement using prevalence-adjusted, bias-adjusted kappa (PABAK). We chose two different cut-offs between the ordinal scores for classifying cows as healthy or diseased for each of the clinical signs, and we compared the ability of the observers to discriminate between healthy and diseased cows for the two cut-offs. Without any formal training of the observers we found PABAK in the range 0.36-0.88 and we concluded that the choice of cut-off had an effect on the observed agreement among the observers.     

Yields and N uptake of barley and ryegrass from soils with added animal manure differing in straw and urine content

Four types of cattle manure were prepared by mixing faeces with different ratios of urine + straw, one manure being faeces without straw and urine. Following 3 to 6 months of storage, the manures were applied in spring or autumn to a sandy loam and a coarse sand in amounts corresponding to 120 kg N ha⁻¹. Spring barley (Hordeum vulgare L.) undersown with perennial ryegrass (Lolium perenne L.) were used as test crops. Barley was harvested at maturity and the wintering ryegrass was cut three times in the second year. Additional mineral N in the form of ¹⁵N-labelled mineral fertilizer (50 kg N ha⁻¹) was added to all barley plots at planting in spring. Non-manured plots receiving only the ¹⁵N-labelled mineral fertilizer were included. Faeces without urine + straw contained more NH₄-N than the other manures and spring incorporation of this manure gave the highest dry matter yield and N uptake of the barley. When faeces without urine + straw was applied in autumn, the yield and N uptake were increased only on the sandy loam. On the coarse sand, the NH₄-N was probably leached as NO₃-N during the winter. The three manures with urine + straw did not affect barley grain yield or total N uptake. Thus these manures did not mineralize nor immobilize measurable quantities of N in the first growth period. On the sandy loam, the patterns of N uptake in ryegrass indicated an increased availability of manure N during the second growth period. The availability of N from the ¹⁵NH₄¹⁵NO₃ was similar in all plots when manures were applied in spring. Less ¹⁵N was taken up by the spring barley when manure was added in autumn compared with crops given ¹⁵NH₄¹⁵NO₃ only. Thus short-term effects of N in cattle faeces stored with or without straw + urine are low. For soils low in mineral N such manures may potentially reduce crop N uptake.     

Effects of long-term annual inputs of straw and organic manure on plant N uptake and soil N fluxes

This study investigated the effects of long‐term annual inputs of animal manure and straw on the rate of gross nitrogen (N) mineralization–immobilization turnover (MIT), net N mineralization and potential nitrification, and examined how these N transformation rates affect plant N availability. The experiment was conducted during May–June 2001 in long‐term field experiments in Askov, Denmark, where organic manure and barley straw had been applied annually for 11 and 20 years prior to the year 2000, respectively. Thus, any differences could be attributed to residual effects from the previous years of application. Inputs of straw and organic manure to soil increased soil organic matter (SOM)‐N content in soil in the order: without straw, without manure < without straw, with manure < with straw, without manure < with straw, with manure. The inputs did not change net N mineralization in the soil. There was a distinct but non‐significant trend towards higher gross N mineralization with increasing SOM‐N. Gross N immobilization was enhanced by straw inputs and to a lesser extent by organic manure inputs, while potential nitrification was enhanced by both amendments. The results show that long‐term annual inputs of straw and organic manure can increase MIT rate and potential nitrification rate without influencing net N mineralization rate. MIT and potential nitrification explained 23–31% of the variation in plant N uptake, while net N mineralization rate only explained 1%. Plant N uptake therefore seems to be more influenced by MIT rate and potential nitrification rate than by net mineralization rate, presumably because mineral N in the transition between gross N mineralization and gross N immobilization is available for assimilation by plants.     

Optimizing farmyard manure utilization by varying the application time and tillage strategy

Abstract. Two field experiments were carried from 1999 to 2001 to assess the effectiveness of autumn, winter and spring application of straw-based farmyard manure (FYM). The soil was a sandy loam containing 106 g clay kg⁻¹ situated in the temperate coastal climate of Denmark. The FYM was applied manually to experimental plots at a target rate of 300 kg N ha⁻¹. The manure was incorporated by three initial tillage strategies (harrowing, rotavating or no-tillage) prior to ploughing. All combinations of tillage strategies were also carried out without manure application. Spring barley ( Hordeum vulgare L.) was grown, followed by ryegrass ( Lolium perenne L.). The results suggest that, as far as circumstances permit, FYM should be applied in spring to achieve the optimum use of nitrogen in the manure. Further, yield and nitrogen uptake did not benefit from harrowing or rotavating the manure before ploughing. When manure was not applied, soil tillage prior to ploughing did not significantly affect grain yield or nitrogen uptake.     

Effects of cropping system and rates of nitrogen in animal slurry and mineral fertilizer on nitrate leaching from a sandy loam

Abstract. Leaching of nitrate from a sandy loam cropped with spring barley, winter wheat and grass was compared in a 4-year lysimeter study. Crops were grown continuously or in a sequence including sugarbeet. Lysimeters were unfertilized or supplied with equivalent amounts of inorganic nitrogen in calcium ammonium nitrate (CAN) or animal slurry according to recommended rates (1N) or 50% above recommended rates (1.5N).
Compared with unfertilized crops, leaching of nitrate increased only slightly when 1N (CAN) was added. Successive annual additions of 1.5N (CAN) or 1N and 1.5N (animal slurry) caused the cumulative loss of nitrate to increase significantly. More nitrate was leached after application of slurry because organic nitrogen in the slurry-was mineralized.
With 1N (CAN) the leaching losses of nitrate were in the following order: continuous spring barley undersown with Italian ryegrass < continuous ley of perennial ryegrass < spring barley in rotation and undersown with grass < perennial ryegrass grown in rotation = winter wheat grown in rotation < sugarbeet in rotation < continuous winter wheat < continuous barley < bare fallow.
At recommended levels of CAN (1N), cumulative nitrate losses over the four years were similar for the crops when grown in rotation or continuously. When crops received 1.5N (CAN) or animal slurry, nitrate losses from the crops grown continuously exceeded those from crops in rotation. Including a catch crop in the continuous cropping system eliminated the differences in nitrate leaching between the two cropping systems.     

Two types of radicals in whole milk powder. Effect of lactose crystallization, lipid oxidation, and browning reactions

Whole milk powder was stored in closed vials at 60 degrees C to induce crystallization of lactose within a short time scale. After an induction period of 3-4 days simultaneous crystallization of lactose, increase of water activity, formation of browning products, and increase of radical content took place. Radicals detected before lactose crystallization were characterized by a narrow ESR spectrum (g = 2.006) and could be depleted by removal of oxygen and therefore were assigned to oxidation processes. Late-stage radicals present after crystallization of lactose gave much wider spectra (g = 2.0048) and were independent of oxygen availability and assigned to late-stage Maillard reaction products. The study indicates that the processes of lactose crystallization, browning, and formation of radical species (g = 2.0048) are strongly coupled, while lipid oxidation is less dependent on the other processes.     

Interactions between soil organic matter level and soil tillage in a growing crop: N mineralization and yield response

Four levels of soil organic matter (SOM) had been established on a coarse sandy loam after application of four combinations of mineral fertilizer, animal manure, straw incorporation and catch crops for 12 years. Soil tillage was carried out in a growing spring barley crop (Hordeum vulgare) to examine the potential for improving the synchrony between soil N mineralization and crop N demand. Tillage raised soil nitrate concentrations temporarily but did not influence barley dry matter (DM) yield. At maturity, both grain DM yield and N uptake were largest on soil with the highest OM level. The previous OM applications had a pronounced influence on crop development and N availability, but soil tillage did not significantly improve the synchrony between soil N mineralization and crop N demand.     

Reassessment of two Boyden chamber methods for measuring canine neutrophil migration: the leading front and the lower surface count assays

Laboratory investigation of neutrophil locomotion has attracted a great deal of attention owing to its potential usefulness to veterinary clinical medicine. Two of the most important principles for measurement of chemotaxis are the leading front and lower surface count techniques. The latter assay has become increasingly popular following the introduction of multi-well chambers utilizing polycarbonate filters. In the present study, this method was compared quantitatively and qualitatively to the leading front assay. Further, the potential usefulness of a simple shape-change assay as a rapid measure of chemotactic activation of neutrophils was assessed and compared with the migration assays. It was concluded that the two migration assays are superior to the shape-change assay, even though both suffer from certain methodological drawbacks. This may be relevant to the elucidation of clinical cases of neutrophil dysfunction.     

Composition and dynamics of plasma in Saturn's magnetosphere

During Cassini's initial orbit, we observed a dynamic magnetosphere composed primarily of a complex mixture of water-derived atomic and molecular ions. We have identified four distinct regions characterized by differences in both bulk plasma properties and ion composition. Protons are the dominant species outside about 9 RS (where RS is the radial distance from the center of Saturn), whereas inside, the plasma consists primarily of a corotating comet-like mix of water-derived ions with approximately 3% N+. Over the A and B rings, we found an ionosphere in which O2+ and O+ are dominant, which suggests the possible existence of a layer of O2 gas similar to the atmospheres of Europa and Ganymede.