Effects of rice straw,biochar and mineral fertiliser on methane (CH<Subscript>4</Subscript>) and nitrous oxide (N<Subscript>2</Subscript>O) emissions from rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) grown in a rain-fed lowland rice soil of Cambodia: a pot experiment

We studied the effects of water regimes and nutrient amendments on CH₄ and N₂O emissions in a 2 × 3 factorial, completely randomised growth chamber experiment. Treatments included continuously flooded (CF) and alternate wetting and drying (AWD), and three organic amendments: no amendment-control, rice straw (RS) and biochar (BC). Compound fertiliser was applied to all treatments. Rice was grown in columns packed with a paddy soil from Cambodia. Results revealed faster mineralisation of organic carbon (RS and BC) when applied in water-saturated conditions lasting for 2 weeks instead of flooding. This resulted in lower total CH₄ emissions in treatments under AWD than those under the CF water regime, namely 44 % in RS treatments and 29 % in BC treatments. Nitrous oxide fluxes were generally non-detectable during the experimental period except after fertilisation events, and the total N₂O–N emissions accounted for on average 1.7 % of the total applied mineral fertiliser N. Overall, the global warming potentials (GWPs) were lower in treatments under AWD than those under the CF water regime except for the control treatment with only mineral fertiliser application. Grain yields were slightly higher in treatments under AWD than the CF water regime. Hence, the yield-scaled GWP was also lower in the treatments under the AWD water regime, namely 51 % in RS, 59 % in BC and 17 % in control treatments. Control treatments had the lowest GWP, but provided the highest yield. The yield-scaled GWP under these treatments was therefore lower than under the other treatments.     

Validation of data collected in the Danish Veterinary Cancer Registry

The Danish Veterinary Cancer Registry (DVCR) was established in 2005 and prospectively collects information about neoplasms in Danish dogs and cats.
The present study evaluated the agreement between veterinary practice records and electronic submissions made to the DVCR from May 2005 through June 2008. The variables compared were gender, breed, diagnosis, date of birth, death and diagnosis, localization and biological behaviour of the neoplasms.
Agreement of 95% between DVCR and the original data were considered acceptable with regard to use of data in studies. Recorded proportions of agreement were: (1) breed: 97.4%; (2) diagnosis: 95.6%; (3) location: 95.6%; (4) biological behaviour: 93.0%; (5) gender: 92.5%; (6) date of death: 91.5%; (7) date of diagnosis: 80.1%; (8) date of birth: 76.7%.
All variables except date of death, birth, and diagnosis met the required 95% agreement limit. Data on dates of birth, death and diagnosis were considered less suitable for further studies.     

Induction of porcine post-weaning multisystemic wasting syndrome (PMWS) in pigs from PMWS unaffected herds following mingling with pigs from PMWS-affected herds

In this paper we present the results from two experimental studies (I and II) investigating whether post-weaning multisystemic wasting syndrome (PMWS) can be induced in pigs from PMWS unaffected herds by mingling with pigs from PMWS-affected herds and to observe whether transportation and/or mingling of healthy pigs from unaffected herds could induce PMWS.The studies comprised pigs from 12 different herds. Eight herds had PMWS while four were unaffected. All 12 herds were found to be infected with PCV2. Pigs from PMWS-affected herds were mingled with pigs from unaffected herds in four separate compartments in both study I and study II. In addition, in study II, four groups of pigs from unaffected herds were included. Two groups with pigs transported and mingled from unaffected herds and two groups with pigs which were only transported. The PMWS diagnoses on the individual pigs were based on lymphoid depletion, histiocytic proliferation and the presence of giant cells or inclusion bodies together with the demonstration of PCV2 in lymphoid tissue.Healthy pigs, in both studies, developed PMWS 4–5 weeks after mingling with pigs clinically affected with PMWS. None of the pigs from unaffected herds which had no contact with pigs from PMWS-affected herds developed clinical signs of PMWS. Transportation and mingling of pigs from PMWS unaffected herds in combination or alone was insufficient to provoke PMWS.     

Influence of slow-release urea on nitrogen balance and portal-drained visceral nutrient flux in beef steers

Two experiments were conducted to evaluate the effects of slow-release urea (SRU) versus feed-grade urea on portal-drained visceral (PDV) nutrient flux, nutrient digestibility, and total N balance in beef steers. Multi-catheterized steers were used to determine effects of intraruminal dosing (Exp. 1; n = 4; 319 +/- 5 kg of BW) or feeding (Exp. 2; n = 10; 4 Holstein steers 236 +/- 43 kg of BW and 6 Angus steers 367 +/- 46 kg of BW) SRU or urea on PDV nutrient flux and blood variables for 10 h after dosing. Intraruminal dosing of SRU (Exp. 1) prevented the rapid increase in ruminal ammonia concentrations that occurred with urea dosing (treatment x time P = 0.001). Although apparent total tract digestibilities of DM, OM, NDF, and ADF were not affected by treatment (P > 0.53, Exp. 2), SRU increased fecal N excretion (49.6 vs. 45.6 g/d; P = 0.04) and reduced apparent total tract N digestibility (61.7 vs. 66.0%; P = 0.003). Transfer of urea from the blood to the gastrointestinal tract occurred for both treatments in Exp. 1 and 2 at all time points with the exception for 0.5 h after dosing of urea in Exp. 1, when urea was actually transferred from the gastrointestinal tract to the blood. In both Exp. 1 and 2, both urea and SRU treatments increased arterial urea concentrations from 0.5 to 6 h after feeding, but arterial urea concentrations were consistently less with SRU (treatment x time P < 0.001, Exp. 1; P = 0.007, Exp. 2). Net portal ammonia release remained relatively consistent across the entire sampling period with SRU treatment, whereas urea treatment increased portal ammonia release in Exp. 1 and tended to have a similar effect in Exp. 2 (treatment x time P = 0.003 and P = 0.11, respectively). Urea treatment also increased hepatic ammonia uptake within 0.5 h (treatment x time P = 0.02, Exp. 1); however, increased total splanchnic release of ammonia for the 2 h after urea treatment dosing suggests that PDV ammonia flux may have exceeded hepatic capacity for removal. Slow-release urea reduces the rapidity of ammonia-N release and may reduce shifts in N metabolism associated with disposal of ammonia. However, SRU increased fecal N excretion and increased urea transfer to the gastrointestinal tract, possibly by reduced SRU hydrolysis or effects on digestion patterns. Despite this, the ability of SRU to protect against the negative effects of urea feeding may be efficacious in some feeding applications.     

Plasma levels of a low-dose constant-rate-infusion of ketamine and its effect on single and repeated nociceptive stimuli in conscious dogs

This study quantitatively investigated the analgesic action of a low-dose constant-rate-infusion (CRI) of racemic ketamine (as a 0.5 mg kg⁻¹ bolus and at a dose rate of 10 μg kg⁻¹ min⁻¹) in conscious dogs using a nociceptive withdrawal reflex (NWR) and with enantioselective measurement of plasma levels of ketamine and norketamine. Withdrawal reflexes evoked by transcutaneous single and repeated electrical stimulation (10 pulses, 5 Hz) of the digital plantar nerve were recorded from the biceps femoris muscle using surface electromyography.Ketamine did not affect NWR thresholds or the recruitment curves after a single nociceptive stimulation. Temporal summation (as evaluated by repeated stimuli) and the evoked behavioural response scores were however reduced compared to baseline demonstrating the antinociceptive activity of ketamine correlated with the peak plasma concentrations. Thereafter the plasma levels at pseudo-steady-state did not modulate temporal summation. Based on these experimental findings low-dose ketamine CRI cannot be recommended for use as a sole analgesic in the dog.     

Metabolic characterization of rumen epithelial tissue from dairy calves fed different starter diets using 1H NMR spectroscopy

The metabolic profile of calf rumen epithelial tissue was for the first time characterized by ¹H NMR spectroscopy of chloroform/methanol extracts. The metabolite profiles comprised a number of amino acids, creatine, taurine, short-chain fatty acids and triglycerides. The effects of two dietary interventions; i) four levels of milk allowance with a concomitant different uptake of starter concentrate, and ii) two diets with varying content of starch and fibre in the concentrate, were elucidated. Partial least square regression analysis revealed that the intensity of NMR signals assigned to leucine, isoleucine and valine (0.90  ppm), propionate (1.06 and 2.18  ppm), lactate (1.32  ppm), butyrate (1.56  ppm), acetate (1.93  ppm), glutamine/glutamate (2.18, 2.35 and 3.75  ppm), creatine (3.04 and 3.94  ppm) and glycine (3.55  ppm) decreased with increasing milk allowance. In addition, the analysis revealed that the main difference between the two diets was the content of propionate in the epithelia tissue extracts. Previous morphological analyses of the same rumen epithelia were not able to detect any significant effects of either milk allowance or dietary starch content. Accordingly, the present study demonstrated that ¹H NMR spectroscopy applied on extracts is a useful tool for metabolite profiling of epithelial tissue and for following the development of epithelia tissue in young calves, and that the technique may be more sensitive to dietary effects than morphological studies.     

Dynamics and determinants of Quercus alba seedling success following savanna encroachment and restoration

The scattered tree layer that defines savannas is important for structuring the understory community and determining patterns of overstory recruitment. However, encroachment by woody plants has altered overstory tree densities and regeneration dynamics. We characterized seedling success of the savanna-forming species Quercus alba within Midwestern (USA) oak savannas that had been degraded by encroachment (control; n = 4) or experimentally restored by removal of encroaching woody vegetation (treatment; n = 4). In early 2004, 981 seedlings were transplanted along transects radiating from tree boles of overstory Q. alba trees to inter-canopy gaps and monitored for three growing seasons. Seedlings in restored sites had greater survival (>2×), height growth (by >50%), and basal diameter growth (by >20%). In general, seedling survival and growth parameters increased with distance from overstory trees and were greatest in inter-canopy gaps of restored sites. By the final growing season (2006), the seedling survival-by-distance from tree correlation was stronger in control (r² = 0.25) than treatment sites (r² = 0.18), due to relatively uniform (and greater) survival at all distances from trees in treatment sites. In 2006, growth parameters (seedling height, diameter, Δ height, Δ diameter, and # leaves) were significantly (and more strongly) positively correlated with distance from trees in treatment sites. However, seedling herbivory was also greater after treatment and increased with distance from overstory trees. To understand seedling/microenvironment relationships, we created logistic (survival) and linear regression models (Δ height, Δ basal diameter, # leaves in 2006). Control seedling models had consistently greater predictive power and included more variables, suggesting that savanna restoration may decouple seedlings from their microenvironments, potentially by decreasing competition for limiting resources. Encroachment of the savannas in this study is limiting regeneration of Q. alba, suggesting substantially altered regeneration dynamics from those under which these savannas originally formed. Initial responses from our test of restoration, however, were promising and mechanical encroachment removal may be a means to promote overstory regeneration of this species. Finally, the savannas in this study appear inherently unstable and a scattered canopy tree configuration is unlikely to persist without regular disturbance, even in the restoration sites. Repeated mechanical thinning treatments with selected retention of recruiting Q. alba individuals or reintroduction of understory fire or grazing animals may be potential mechanisms for promoting long-term persistence of savannas at these sites.     

Litterfall and nutrient return in five tree species in a common garden experiment

Canopy litterfall is a significant pathway for return of nutrients and carbon (C) to the soil in forest ecosystems. Litterfall was studied in five even-aged stands of Norway spruce, Sitka spruce, Douglas-fir, European beech and common oak at three different locations in Denmark; two sandy sites, Ulborg and Lindet in Jutland, and one loamy site, Frederiksborg on Zealand. Litterfall was collected during three years from 1994 to 1996 in all five species and during six years from 1994 to 1999 in Norway spruce, Sitka spruce and European beech. The average total litterfall was in the range of 3200–3700 kg ha⁻¹ yr⁻¹ and did not differ significantly among tree species. There were no significant differences in total litterfall among sites during the short period, but during the longer period the richer site Frederiksborg had significantly higher total and foliar litterfall amounts compared to the more nutrient-poor sites Lindet and Ulborg. There were close relationships between foliar and total litterfall suggesting that foliar litterfall can be reliably estimated from total litterfall. Beech and oak bud scale litter was significantly related to foliar litterfall. The amount of branch and twig litter was significantly higher in oak than in other tree species. The average foliar litterfall was well related to the annual volume increment. The relationship differed markedly from previously reported relationships based on global litterfall data suggesting that such relationships are better evaluated at the regional level. Nutrient concentrations and fluxes in foliar litterfall were not significantly different among the five tree species. However, there was a significant effect of site on most nutrient concentrations of the three litterfall fractions, and foliar fluxes of P, Ca and Mn were all significantly highest at Frederiksborg and lowest at Ulborg. The similarity in litterfall inputs to the forest floor under these five tree species suggested that previous reports of large variability in forest floor accumulation should primarily be attributed to differences in litter decomposition.     

Exploratory Study of Potato Cultivar Differences in Sensory and Hedonistic Applicability Tests

From a potato cultivar breeding database including 2,143 named cultivars and clones, 11 cultivars that spanned the major variation in cultivar quality were selected for subsequent sensory and hedonistic applicability tests. A tailor-made sensory profile of the cultivars was developed for four different cooking procedures: boiled, mashed, oven-fried and oven-cooked potatoes. A sensory profile consisted of the four to five most important sensory attributes, and the data was combined with the applicability data using multivariate data analysis. Ultimately, the variation in eating quality was evaluated in a hedonistic test with expert evaluation of applicability. Three gourmet chefs prepared the different cultivars as boiled potatoes, mashed potatoes, baked potatoes and oven-fried potatoes and evaluated the cultivars’ applicability, while a sensory panel consisting of nine judges evaluated the sensory quality. The multivariate data analysis revealed a significant diversity amongst the cultivars for the different cooking procedures. A single PCA bi-plot was able to provide a simple and clear overview of the gastronomic diversity and possible applications of the different potato cultivars.