Phylogenetic analysis of highly pathogenic avian influenza A(H5N8) virus outbreak strains provides evidence for four separate introductions and one between-poultry farm transmission in the Netherlands, November 2014

Phylogenetic analysis of highly pathogenic avian influenza A(H5N8) virus strains causing outbreaks in Dutch poultry farms in 2014 provides evidence for separate introduction of the virus in four outbreaks in farms located 16-112 km from each other and for between-farm transmission between the third and fourth outbreak in farms located 550 m from each other. In addition, the analysis showed that all European and two Japanese H5N8 virus strains are very closely related and seem to originate from a calculated common ancestor, which arose between July and September 2014. Our findings suggest that the Dutch outbreak virus strain 'Ter Aar' and the first German outbreak strain from 2014 shared a common ancestor. In addition, the data indicate that the Dutch outbreak viruses descended from an H5N8 virus that circulated around 2009 in Asia, possibly China, and subsequently spread to South Korea and Japan and finally also to Europe. Evolution of the virus seemed to follow a parallel track in Japan and Europe, which supports the hypothesis that H5N8 virus was exchanged between migratory wild waterfowl at their breeding grounds in Siberia and from there was carried by migrating waterfowl to Europe.

Schmallenberg virus outbreak in the Netherlands: routine diagnostics and test results

At the end of 2011, a new Orthobunyavirus was discovered in Germany and named Schmallenberg virus (SBV). In the Netherlands malformations in new-born ruminants were made notifiable from the 20th of December 2011. After a notification, malformed new-borns were necropsied and brain tissue was sampled for reverse transcription-polymerase chain reaction (RT-PCR). In addition, blood samples from mothers of affected new-borns were tested for antibodies in a virus neutralization test (VNT). The aim of this study was to summarize and evaluate the diagnostic data obtained and to gain insight into the possible regional differences. In total 2166 brains were tested: 800 from lambs, 1301 from calves and 65 from goat kids. Furthermore 1394 blood samples were tested: 458 from ewes, 899 from cows and 37 from goats. Results showed that 29% of the lamb brains, 14% of the calf brains, and 9% of the goat kid brains were RT-PCR positive. The number of malformed and RT-PCR positive lambs decreased over time while the number of malformed and RT-PCR positive calves increased. In the VNT 92% of the ewes, 96% of the cows and 43% of the goats tested positive. Combining RT-PCR and VNT results, 18% of all farms tested positive in both the RT-PCR and VNT. The relative sensitivity and specificity of the RT-PCR are 19% and 97% respectively, and of the VNT 99% and 6%. The results show a widespread exposure to SBV and the regional evaluation seems to indicate an introduction of SBV in the central/eastern part.

Effects of vitamin E supplementation on and the association of body condition score with changes in peroxidative biomarkers and antioxidants around calving in dairy heifers

The objective of this study was to investigate the effect of vitamin E supplementation on oxidative status in blood, liver, milk, and ovarian follicular fluid in periparturient heifers. Vitamin E supplementation started 8 wk before calving and continued until 8 wk postpartum. Grass silage was the main forage fed during the experiment. In addition, supplemented heifers (n=9) received 3,000I U of vitamin E daily on a carrier food; control heifers (n=9) consumed only the carrier food. Blood samples and liver biopsies were taken frequently throughout the study and ovarian follicular fluid was sampled at 8 wk postpartum. Body condition score was scored weekly and milk yield was measured daily. A marker of oxidative damage, determinable reactive oxygen metabolites (d-ROM), and a set of antioxidants were measured in blood, liver, milk, and ovarian follicular fluid. Control heifers had a low vitamin E status, and selenium status was marginal in control and supplemented heifers. Vitamin E supplementation increased vitamin E concentrations in blood, liver, and ovarian follicular fluid and increased triacylglycerol in liver. Serum d-ROM were not reduced by vitamin E supplementation. Superoxide dismutase and glutathione peroxidase activity in red blood cells and liver and glutathione peroxidase activity in ovarian follicular fluid were not affected by vitamin E supplementation and they were not increased around calving. Protein thiol groups and ratio of reduced glutathione to oxidized glutathione were also not increased around calving. These results suggest that heifers around calving experience a low level of oxidative processes. This might be caused by lower than expected milk production attributed to a low forage intake. Serum d-ROM were negatively correlated with protein thiol groups and positively correlated with the activity of glutathione peroxidase in red blood cells, oxidized glutathione, and the ratio of reduced glutathione and oxidized glutathione in serum. The lack of treatment effects allowed estimation of the effects of body condition 4 wk before calving and the loss of body condition on markers of lipid peroxidation and antioxidants. A trend that a body condition of >or=3 might result in more oxidative damage measured by serum d-ROM was observed, but fatter heifers had a significantly higher ratio of reduced glutathione to oxidized glutathione.

Comparison of the oxidative status of vitamin E-supplemented and non-supplemented cows under field conditions

The effect of oral vitamin E supplementation during the dry period on serum biomarkers of oxidative status was evaluated in an observational field study. Ninety-eight cows were selected from 26 herds in the Netherlands. On 15 farms dry cows were supplemented with a dry-cow mineral mix containing 1000 IU vitamin E (vitamin E+ group, n = 52), and on 11 other farms dry cows did not receive the supplement (control group, n = 48). A blood sample was taken from all cows between 0 and 28 days before calving. Serum levels of alpha-tocopherol, cholesterol, triacylglycerol, superoxide dismutase (SOD), glutathione peroxidase (GSHpx), uric acid, albumin, protein sulphydryl oxidation level, reactive oxygen metabolites (ROM), iron, the ferric reducing ability (FRAP), and malondialdehyde (MDA) were measured. Alpha-tocopherol levels were significantly higher in the vitamin E+ group, as was the alpha-tocopherol:cholesterol ratio. MDA levels were significantly lower in the vitamin E+ group, suggesting that levels of lipid peroxidation were lower with vitamin E supplementation. In conclusion, vitamin E supplementation increases alpha-tocopherol and lowers MDA serum levels.

[Rupture of the ventral serrate muscles (Flying Scapulas) as a symptom of muscular dystrophy in Holstein-Friesian heifers on a Dutch dairy farm]

Within a week of being turned out to pasture, 3 of 30 heifers displayed a symptom described in the literature as "Flying Scapulas". The cause of this symptom is severe muscular dystrophy, with subsequent rupture of the ventral serrate muscles. Blood analysis revealed a deficiency of both vitamin E and selenium in all three heifers. No new clinical cases of muscular dystrophy were observed after the animals were housed and given vitamin E and selenium supplements. As far as is known, this is the first report in which a deficiency of both vitamin E and selenium was found in animals with the clinical symptoms of Flying Scapulas. This is the first description of Flying Scapulas in cattle in The Netherlands.