Prevalence of Cryptosporidium and Giardia in free-ranging wild cervids in Norway

Faecal samples were collected from 1,190 wild cervids in Norway and analyzed for cysts/oocysts of the protozoan parasites Giardia and Cryptosporidium. Samples were from calves, yearlings and adults of moose (Alces alces), red deer (Cervus elaphus), roe deer (Capreolus capreolus) and reindeer (Rangifer tarandus) shot during the hunting season. Cryptosporidium was found in 15 (3.3%) of 455 moose, 1 (0.3%) of 289 red deer, 18 (6.2%) of 291 roe deer, but was not found in any of 155 reindeer. Giardia was found in 56 (12.3%) moose, 5 (1.7%) red deer, 45 (15.5%) roe deer and 11 (7.1%) reindeer. The calves had the highest prevalence of infection, but this was only statistically significant for Giardia in moose and for Cryptosporidium and Giardia in roe deer. Calves generally had the highest intensity of infection, but this difference was only statistically significant for calves with Giarda and the highest intensity of infection. Both Giardia and Cryptosporidium were found in samples from several geographical areas, indicating that these parasites are distributed among the cervid population in all parts of Norway, especially in moose and roe deer. This is the first published report of Cryptosporidium in moose and of Giardia in reindeer.     

Status of selenium and vitamin E on Norwegian organic sheep and dairy cattle farms

Herbage selenium (Se) concentration is generally low in Norway. It is unknown whether feeding practices on Norwegian organic farms fulfil the dietary needs of Se and vitamin E for sheep and dairy cattle. Therefore we analysed Se in soil and herbage, and Se and vitamin E in animal blood in the indoor feeding season at 14 organic dairy and 14 organic sheep farms. The herbage Se concentration was low. Approximately 50 and 35% of all samples in the first and second cut, respectively, had Se concentrations below the detection limit of 0.01 mg/kg dry matter (DM). The median (10th, 90th percentile) Se concentrations were <0.01 (<0.01, 0.03) and 0.02 (<0.01, 0.06) mg/kg DM in the first and second cuts, respectively. Whole blood Se concentrations were 0.10 (0.04, 0.15) μg/g in dairy cattle and 0.14 (0.03, 0.26) μg/g in sheep. Vitamin E concentrations were 4.2 (2.7, 8.4) mg/l in dairy cattle and 1.3 (0.9, 2.4) mg/l in sheep. None of the soil or plant variables explained the variation in herbage Se concentration, although Se in soil and plant tended to be correlated. Herbage Se concentration was inadequate to meet the dietary Se requirements. Vitamin E requirement was only met in dairy herds. We recommend Se and vitamin E supplementation to ruminants on organic farms.     

Natural and experimental Salmonella Typhimurium infections in foxes (Vulpes vulpes)

The red fox (Vulpes vulpes) can be considered as a relevant indicator species for Salmonella in the local environment and Salmonella faecal carriage was investigated in 215 red foxes in Norway shot during the winters 2002/2003 and 2003/2004. Fourteen (6.5%) of the foxes carried Salmonella. Four isolates were determined as serovars Kottbus (n=2) and Hessarek (n=2) of Salmonella enterica subspecies enterica, and one as S. enterica subspecies IIIb:61:k:1,5,(7). The remaining nine isolates were S. enterica subspecies enterica serovar Typhimurium 4,12:i:1,2 and all displayed the same pulsed-field gel electrophoresis (PFGE) profile designated A2. This serovar regularly causes disease outbreaks amongst small passerine birds during winter and most of these outbreaks are associated with the PFGE profile A2. The results strongly indicated that the Salmonella Typhimurium infections in red foxes were primarily acquired through ingestion of infected small passerines. To investigate the capability of the A2 strain to establish a true intestinal infection in the fox an inoculation experiment with an A2 isolate from small passerines was carried out in farmed silver foxes (V. vulpes). The experiment also included one strain with an uncommonly occurring profile (X201) from small passerines. To highlight possible differences in capability of the two inoculation strains to pass the acid gastric juice in the fox, in vitro studies of their acid tolerance was carried out. Also their catalase activity and biofilm production were studied. All three foxes inoculated with the A2 strain developed sub-clinical intestinal infection of 2 weeks duration, whereas none of the three foxes inoculated with the X201 strain shed this bacterium. The X201 strain displayed a much lower capability, than the A2 strain, to survive at pH 3 in vitro. The low acid tolerance probably made it difficult for the X201 strain to pass the stomach and establish an intestinal infection in the experimental foxes. Reduced catalase activity and biofilm production were found for the X201 strain, indicating that the low acid tolerance was caused by a defect in the stationary-phase stress response system.     

Organic selenium supplementation increased selenium concentrations in ewe and newborn lamb blood and in slaughter lamb meat compared to inorganic selenium supplementation

Background

Selenium is part of the antioxidant defence system in animals and humans. The available selenium concentration in soil is low in many regions of the world. The purpose of this study was to evaluate the effect of organic versus inorganic selenium supplementation on selenium status of ewes, their lambs, and slaughter lambs.

Methods

Ewes on four organic farms were allocated five or six to 18 pens. The ewes were given either 20 mg/kg inorganic selenium as sodium selenite or organic selenium as selenized nonviable yeast supplementation for the two last months of pregnancy. Stipulated selenium concentrations in the rations were below 0.40 mg/kg dry matter. In addition 20 male lambs were given supplements from November until they were slaughtered in March. Silage, hay, concentrates, and individual ewe blood samples were taken before and after the mineral supplementation period, and blood samples were taken from the newborn lambs. Blood samples from ewes and lambs in the same pens were pooled. Muscle samples were taken from slaughter lambs in March. Selenium concentrations were determined by atomic absorption spectrometry with a hydride generator system. In the ANOVA model, selenium concentration was the continuous response variable, and selenium source and farm were the nominal effect variables. Two-sample t-test was used to compare selenium concentrations in muscle samples from the slaughtered lambs that received either organic or inorganic selenium supplements.

Results

In all ewe pens the whole blood selenium concentrations increased during the experimental period. In addition, ewe pens that received organic selenium had significantly higher whole blood selenium concentrations (mean 0.28 μg/g) than ewe pens that received inorganic selenium (mean 0.24 μg/g). Most prominent, however, was the difference in their lambs; whole blood mean selenium concentration in lambs from mothers that received organic selenium (mean 0.27 μg/g) was 30% higher than in lambs from mothers that received inorganic selenium (mean 0.21 μg/g). Slaughter lambs that received organic selenium had 50% higher meat selenium concentrations (mean 0.12 mg/kg wet weight) than lambs that received inorganic selenium (mean 0.08 mg/kg wet weight).

Conclusion

Organic selenium supplementation gave higher selenium concentration in ewe and newborn lamb blood and slaughter lamb meat than inorganic selenium supplementation.     

Soil Solution Chemical Response to Two Decades of Experimental Acidification at the Bear Brook Watershed in Maine

We examined long-term changes in soil solution chemistry associated with experimental, whole watershed-acidification at the Bear Brook Watershed in Maine (BBWM). At BBWM, the West Bear (WB) watershed has been treated with bimonthly additions of ((NH₄)₂ SO₄) since 1989. The adjacent East Bear (EB) watershed serves as a biogeochemical reference. Soil solution chemistry in the EB watershed was relatively stable from 1989?C2007, with the exception of declining SO₄?CS concentrations associated with a progressive decline in SO₄?CS deposition during this period. Soil solution chemistry in WB reflected a progressive change in acid-neutralization mechanisms from base cation buffering to Al buffering associated with treatment during this period. Total dissolved Al concentrations progressively increased over time and were ~4× higher in 2007 than in 1989. Treatment of WB was also associated with long-term increases in soil solution H⁺, SO₄?CS, and NO₃?CN, whereas soil solution dissolved organic carbon (DOC) was unresponsive to treatment. For solutes such as Ca, H⁺, and SO₄?CS, changes in stream chemistry were generally parallel to changes in soil solution chemistry, indicating a close coupling of terrestrial and aquatic processes that regulate the chemistry of solutions in this first-order stream watershed. For other solutes such as Al and DOC, solute concentrations were higher in soil solutions compared with streams, suggesting that sorption and transformation processes along hydrologic flow-paths were important in regulating the chemistry of solutions and the transport of these solutes.     

Bedding hygiene,cleanliness and lying behaviour for heifers housed on wood chip or straw deep bedding

The aim of this project was to compare the hygienic quality of the bedding, as well as the parasitic load, cleanliness and lying behaviour in heifers kept on either straw or wood chip deep bedding. Fourteen heifers kept in two pens were housed on straw or wood chip bedding for 43 days, after which the bedding material was switched for 43 additional days. Significantly more mould was found in wood chip than in straw and there was a tendency towards less yeast in wood chip. The heifers had a low faecal parasitic load. The results indicate that the wood chip treatment resulted in somewhat cleaner animals. The heifers had a significantly longer total lying time when kept on straw. In conclusion, wood chip deep bedding could be an option as bedding material, but the impact on hygiene of bedding material and lying behaviour needs to be further investigated.     

Impact of starvation and handling stress on rigor development and quality of Atlantic salmon (Salmon salar L)

Farmed Atlantic salmon (Salmo salar L) were fed to satiation or starved for 35 d, and subjected to acute pre-slaughter stress or careful handling before slaughtering. Rigor development, post-mortem energy metabolism and quality variations were analysed during 72 h cold storage. The body weight averaged 2.9 and 3.5 kg of the fed and starved salmon, respectively. The starved salmon had lower condition factor (0.99 vs. 1.11) and higher slaughter yield (92.6 vs. 87.5%), but the fat content was similar (11.8–12.9%) in the fed and starved salmon. The initial glycogen level was lower in the starved salmon (21 vs. 29 μmol g^− 1), whereas initial ATP levels (6.4–6.6 μmol g^− 1) were not affected by starvation. Pre-slaughter stress accelerated rigor development, stimulated lactate formation through post-mortem glycolysis, and increased the breakdown of ATP and CP. The effect of stress on rigor development was less pronounced in starved salmon, and a significant interaction was observed between nutritional status and stress. Rigor development was closely correlated to ATP breakdown, especially in fillets. Acute stress accelerated flesh softening during ice storage. After 72 h storage, the fillets of the starved salmon exposed to careful slaughter handling had the significantly firmest texture, whereas the most intense fillet colour was observed in the starved/stressed salmon. Liquid leakage from the muscle during cold storage was lower in the starved salmon, but pre-slaughter stress had no significant impact. It is concluded that a starvation period of five weeks can improve the resistant to acute stress prior to slaughtering of Atlantic salmon that in turn hampers rigor development.     

Rapid and non-invasive measurements of fat and pigment concentrations in live and slaughtered Atlantic salmon (Salmo salar L.)

The aim of this study was to non-invasively determine fat and pigment concentrations in salmon muscle based on visible and near infrared (VIS/NIR) spectroscopy measurements of live/whole fish and fillets, and by means of digital photography (DP) of fillets. The fish used were two populations of farmed Atlantic salmon (Salmo salar L.) consisting of 46 salmon averaging 0.7 kg (range 0.17–1.7 kg, Group S) and 30 salmon averaging 2.3 kg (range 1.4–4.1 kg, Group L). Chemical analyses (fat and pigment content) and computerized tomography, CT (fat content) were used as reference methods. Group L was analysed in the live state (VIS/NIR), after gutting (VIS/NIR and CT), and as fillets (VIS/NIR and DP). Group S was analysed in the gutted state (VIS/NIR) and as fillets (VIS/NIR and DP). VIS spectroscopy predictions of pigment in whole salmon from Group S were obtained with a root mean square error of prediction (RMSEP) of 0.9 mg kg^− 1 astaxanthin, and a correlation between VIS spectroscopy predicted and chemically measured pigment of r = 0.85 (p < 0.0001). The fat concentration was determined by the NIR spectroscopy in live fish with RMSEP = 1.0 fat% unit, and a correlation with chemical reference values of r = 0.94 (p < 0.0001). Fat predictions from NIR spectroscopy correlated also well with predictions from CT analyses, r = 0.95 (p < 0.0001). VIS spectroscopy and DP were equally well suited to determine pigment concentrations in salmon fillets, with prediction errors of only 0.4 mg kg^− 1 astaxanthin, and a correlation with chemically determined pigment of r = 0.92 (p < 0.0001). The results obtained in the present study are the first to demonstrate successful non-invasive pigment predictions in whole salmon using VIS/NIR spectroscopy, and the possibility for simultaneous, rapid and non-destructive quantification of fat and pigment concentrations.     

A severe outbreak of contagious ecthyma (orf) in a free-ranging musk ox (Ovibos moschatus) population in Norway

During July-October 2004, 19 (18 calves, 1 yearling) free-ranging musk oxen (Ovibos moschatus) at Dovre, Norway, were observed with contagious echtyma-like lesions, and 16 of them were euthanized. Six musk oxen were subjected to necropsy, histopathological and microbiological examinations. All euthanized animals had lesions consistent with contagious ecthyma presenting as wart-like, scabby lesions on the muzzle, lips, oral mucosa and limbs to a variable extent. The histopathological examination showed pustular dermatitis characterized by epidermal proliferation, reticular degeneration, degenerating keratinocytes with intracytoplasmic eosinophilic inclusion bodies, vesicopustules, microabscesses and multifocal ulcerations in the epidermis which was covered by a serocellular crust. Pathology and bacteriology showed evidence of secondary infections in the skin and draining lymph nodes. Electron microscopy (negative staining) of lesions from four animals detected parapoxvirus with the typical arrangement of the outer protein filaments. Parapoxvirus DNA was detected in tissue samples from two examined animals by polymerase chain reaction (PCR) with primers from the B2L-gene. A DNA sequence of 326 nucleotides from the amplicon was compared with similar DNA sequences from parapoxvirus isolated from sheep, reindeer, musk ox and cattle. The outbreak was caused by a virus similar to other circulating orf virus variants in Norway. Antibodies against parapoxvirus were detected with a virus neutralization test in 3 of 35 musk oxen (8.6%) sampled at Dovre between 2004 and 2006. This is the first report of a severe outbreak of contagious ecthyma in free-ranging musk oxen.     

Temporal changes in texture, gaping, composition and copper status of Atlantic salmon (Salmo salar, L) fed moist feed or extruded dry feed

Temporal development in product quality and copper status was investigated in Atlantic salmon (initial weight 2.3 kg) fed alginate-based moist feed (MF) or commercial extruded dry feed (DF). The fieldwork was conducted from January to May in sea-cages (800 m³) off the Norwegian west coast. The dry matter content (DM) in the muscle of the MF group was stable at about 32% throughout the experiment, while the DM of DF group increased linearly from 32% to 35%. Salmon were sampled for analyses of Cu status, fillet gaping, texture and pH in March and April. The serum Cu content of the MF group was highest in March, but no significant effect of dietary treatment was observed on Cu status of muscle or liver. The Cu level in serum and muscle decreased from March to April in both fish groups, but the hepatic Cu level showed no temporal changes. Gaping incidence and pH were higher in the MF group in April compared with the DF group and, for both fish groups, fillet gaping was higher and hardness was lower in April than in March. Variation in serum Cu level explained 32% of the variation in fillet hardness, and serum and muscle Cu level related negatively with gaping. At the end of the experiment the condition factor, and fillet and visceral fat contents were higher in the DF group, while sensory evaluated hardness and tastiness were similar for both dietary treatments. In conclusion, sampling time had a greater impact on Cu status, texture and gaping than dietary treatment during springtime in adult Atlantic salmon. Dietary treatment significantly affected body shape, and fat and dry matter contents.