Nitrogen distribution as affected by stocking density in a combined production system of energy crops and free-range pigs

Free-range pig production is typically associated with high risks of nitrogen (N) leaching due to the pigs excretory behaviour creating nitrogen ‘hotspots’ and rooting behaviour destroying the grass sward. This challenge is reinforced at high animal densities causing high nitrogen deposition. A combined production of pigs and perennial energy crops was hypothesized to benefit the environment because crops like miscanthus (Miscanthus), willow (Salix) and poplar (Populus) may persist despite pig rooting, take up nutrients and thereby minimise N-losses. Thus, the aim was to assess the risk of nitrate leaching by investigating the distribution of soil mineral N as influenced by stocking density in a system with zones of perennial energy crops and grass. For each of two seasons 36 growing pigs with an initial mean live weight of 55 kg (spring) and 48 kg (autumn), respectively, were separated into 6 paddocks of two stocking densities (117 and 367 m² pig^?1), respectively. Soil mineral N was measured in 0–25 and 25–75 cm depth at three occasions. N balances showed that N inputs exceeded N outputs by 626 and 185 kg N ha^?1 for high and low stocking density. The pigs caused an uneven distribution of mineral N across the paddocks with highest contents in zones with willow & poplar. Stocking density had a significant effect on soil mineral N. Immediately after the second batch of pigs, average mineral N in the 0–75 cm soil layer was on average 227 and 83 kg N ha^?1 at high and low stocking density, respectively. During winter period with no pigs, soil mineral N content in the 0–75 cm soil layer was reduced by almost 100 kg N ha^?1 in paddocks with high stocking density against only 4 kg in paddocks with low stocking density. It is concluded that risk of elevated nitrate leaching compared to other cropping systems was low at the low stocking density, which therefore represents a promising pathway for a combined production of energy crops and free-range pigs.     

Circulating let‐7g is down‐regulated in Bernese Mountain dogs with disseminated histiocytic sarcoma and carcinomas – a prospective study

Cancer is a prevalent cause of mortality in Bernese mountain dogs (BMDs). Circulating microRNAs (miRNAs) are found in blood and have been identified as promising biomarkers in various neoplastic diseases in humans. In the current study, the expression profile of different types of miRNAs was investigated in healthy BMDs and BMDs with cancer. Seven healthy and six non‐treated BMDs with cancer [four with disseminated histiocytic sarcomas (DHS)] were enrolled in this study. Clinical evaluations including physical examination, blood analysis, urinalysis and diagnostic imaging were performed on all dogs. Twenty‐four different miRNAs were profiled from RNA isolated from whole blood preserved in PAXgene^® tubes using quantitative real‐time PCR (qPCR). The miRNA let‐7g was significantly down‐regulated in dogs with cancer (P = 0.002) and dogs with DHS (P = 0.011) compared with healthy controls. This miRNA is a known tumour suppressor and further analyses are warranted to assess its value as a non‐invasive biomarker for early detection of different types of cancer in BMDs.     

Analysis of serum proteins, using agarose electrophoresis in normal dogs and in dogs naturally infected with Dirofilaria immitis.

The electrophoretic pattern of 130 serum samples from clinically normal dogs was evaluated, using agarose as the supporting matrix. The relative mobility of each globulin fraction in relationship to the mobility of albumin was determined in 70 dogs, and nomenclature based on the mobilities (Rf values) was proposed. Biuret protein determinations were done, and relative and absolute values of each serum protein fraction were determined. Changes in the fractions of serum proteins were evaluated in regard to sex and age of the dogs and the presence of microfilariae of Dirofilaria immitis, as determined by modified Knott tests.     

Establishment and Multiplication of Virus-free Nuclear Stocks of Potatoes in Denmark1

A programme of meristem-stem tip culture of potato was initiated in Denmark in 1977 to eradicate Corynebacterium sepedonicum and at the same time produce virus-free stocks. The procedures for obtaining the cultures, and ksting for viruses, at the National Institute of Plant Pathology are described. The first tuber generation is further propagated for 2 years by the Research Institute for Potatoes at Tylstrup. Selected growers then multiply the « meristem potatoes >> under the pre-basic system for another 3 years, under the supervision of the National Committee for Health Control of Seed Potatoes.     

Qualitative evaluation of irregularly spiculated red blood cells in the dog

Irregularly speculated red blood cells (IS-RBC) were quantified on fresh blood fixed in glutaraldehyde and were compared to RBC shape changes observed on Wright's-stained blood smears, RBC histograms, and RBC distribution widths (RDW). IS-RBC were infrequently found in healthy control dogs. Twenty dogs with increased IS-RBC were evaluated. The most common clinical diagnoses were lymphosarcoma (seven cases), glomerulonephritis (two cases), hemangiosarcoma (two cases), and chronic liver disease (two cases). Five cases had evidence of disseminated intravascular coagulopathy. In 12 of the 20 cases, keratocytes, schizocytes, and/or acanthocytes were detected in the monolayer area of blood smears. In the other seven cases, keratocytes, schizocytes, and/or acanthocytes were found only in thick areas of the smears. Acanthocytes were the most frequent cell type seen, while schizocytes were absent or present only in low numbers. RBC histograms had a shoulder on the left side of the tracing in six of the 20 cases, suggesting the presence of RBC fragments; however, cases with evidence of platelet aggregation had similar shoulders in RBC histograms. Red cell distribution widths were increased in 12 of the 20 cases with IS-RBC; however, the increase in RDW did not correlate with the presence of schizocytes and was most likely the result of reticulocytosis. This study suggests that quantitative evaluation of RBC shape is a more sensitive method for detection of mild RBC fragmentation when compared to blood smear evaluation, RBC histograms, or RDW. Additionally, acanthocyte-type cells were the most frequent shape change seen in dogs with evidence of RBC fragmentation.     

Adenosine 3',5'-monophosphate in plasma, urine, and native and isoproterenol-stimulated leukocytes of dogs.

Adenosine 3',5'-monophosphate (cAMP) was determined by means of a commercial kit in urine and plasma from 40 hospitalized dogs and in native and isoproternol-stimulated leukocytes from 30 of these animals. Mean urine and plasma concentrations were 6.1 micron and 14 nM, with 95% tolerance limits ("normal values") ranging from 0.0 to 12 micron and 0.21 to 27 nM, respectively. The plasma concentration was approximately half the value previously reported for experimental dogs. The median cAMP content in native leukocytes was 5.9 pmol/10(7) cells. The mean response to isoproterenol was 0.85 pmol/10(7) cells, much less than in human leukocytes. The response was statistically significant (P less than 0.01), but was so small that it is unlikely to be measurably affected in atopic dogs.     

A randomized, controlled study to evaluate the steroid sparing effect of essential fatty acid supplementation in the treatment of canine atopic dermatitis

A randomized, double blind, placebo-controlled multicentre clinical trial of 12 weeks' duration was undertaken in 60 dogs with atopic dermatitis to evaluate the steroid sparing effect of essential fatty acid supplementation. The dogs were randomly assigned to receive either a combination of borage seed oil and fish oil or a placebo, in addition to prednisolone tablets. All dogs received a standardized basal diet. Owners of the dogs recorded pruritus daily using a 10 cm visual analog scale and the dosage of prednisolone was established based on the pruritus score, according to written instructions. The dosage of prednisolone and the use of any concurrent treatment (shampoo and/or ear-cleanser) were recorded by the owner on a daily basis. The investigators graded the skin lesions at days 0, 42 and 84. The use of prednisolone during the test period was lower in the active group, but the difference was not statistically significant (P = 0.32). The test period was sequentially divided into 43-84, 50-84, 57-84, 64-84, 71-84 and 78-84 days. On day 64, the difference between the active group and the placebo group reached statistical significance (P = 0.04) with an increasing difference towards the end of the study. A statistically significant reduction in the pruritus scores and the total clinical scores from day 0 to day 84 was apparent in both groups (P < 0.0001). At the end of the study, both the pruritus score and the total clinical score were lower in the active group. Our findings indicate a steroid sparing effect of essential fatty acid supplementation in canine atopic dermatitis and, furthermore, that there is a time lag before the effect is attained.     

Splanchnic metabolism of volatile fatty acids absorbed from the washed reticulorumen of steers

Six steers fitted with a ruminal cannula and chronic indwelling catheters in the mesenteric artery, mesenteric vein, hepatic portal vein, hepatic vein, as well as in the right ruminal vein were used to study metabolism of VFA absorbed from buffers in the emptied and washed reticulorumen. [2-(13)C]Acetate was infused into a jugular vein to study portal-drained visceral (PDV) uptake of arterial acetate, hepatic unidirectional uptake of acetate, and whole-body irreversible loss rate (ILR). Isobutyrate was infused into the right ruminal vein to calibrate VFA fluxes measured in the portal vein. On sampling days, the rumen was emptied and incubated in sequence with a 0-buffer (bicarbonate buffer without VFA), a VFA-buffer plus continuous intraruminal infusion of VFA, and finally another 0-buffer. Ruminal VFA absorption was determined as VFA uptake from the VFA-buffer and metabolic effects determined as the difference between metabolite fluxes with VFA-buffer and 0-buffers. Steady absorption rates of VFA were maintained during VFA-buffer incubations (4 h; 592+/-16, 257+/-5, 127+/-2, 17+/-<1, 20+/-<1 mmol/h, respectively, of acetate, propionate, butyrate, isovalerate, and valerate). The portal flux of acetate corrected for PDV uptake of arterial acetate accounted for 105+/-3% of the acetate absorption from the rumen, and the net portal flux of propionate accounted for 91+/-2% of propionate absorption. Considerably less butyrate (27+/-3%) and valerate (30+/-3%) could be accounted for in the portal vein. The sum of portal VFA and 3-hydroxybutyrate as well as lactate represented 99+/-3% of total VFA acetyl units and 103+/-2% of VFA propionyl units. Estimates are maximum because no accounting was made for lactate derived from glycolysis in the PDV. The net splanchnic flux of VFA, lactate, 3-hydroxybutyrate, and glucose accounted for 64+/-2% of VFA acetyl units and 34+/-5% of VFA propionyl units. Results indicate that there is a low "first-pass" uptake of acetate and propionate in the ruminal epithelium of cattle, whereas butyrate and valerate are extensively metabolized, though seemingly not oxidized to carbon dioxide in the epithelium but repackaged into acetate, 3-hydroxybutyrate, and perhaps other metabolites. When PDV "second-pass" uptake of arterial nutrients is accounted for, PDV fluxes of VFA, lactate, and 3-hydroxybutyrate represent VFA production in the gastrointestinal tract and thereby VFA availability to the ruminant animal.     

A biological network describing infection with Mycoplasma hyopneumoniae in swine herds

We have made a biological model based on a Bayesian network for risk factors for infection with Mycoplasma hyopneumoniae (Mycoplasma) in slaughter pigs; prevalence of infection is based on veterinary examinations. The model is a probabilistic/stochastic determination based on the inherent biological uncertainty of the severity of infection with Mycoplasma and the derived stochastic effects on productivity for the herd. The conditional probabilities in the Bayesian network are based on published studies and expert opinions. We used the model to calculate how the risk factors and our evidence about the herd influenced our view on the severity of Mycoplasma, and how our view changed when we had more veterinary evidence. We also show how one can use the model to deal with conflicting examinations.