Effect of monensin and essential oils on performance and energy metabolism of transition dairy cows

This work examined preventive effects of a dietary and a medical intervention measure on postpartum (p.p.) ketogenesis in dairy cows overconditioned in late pregnancy. Sixty German Holstein cows were allocated 6 weeks antepartum (a.p.) to three high body condition score (BCS) groups (BCS 3.95 ± 0.08) and one low BCS group (LC, BCS 2.77 ± 0.14). Concentrate proportion in diet a.p. was higher (60% vs. 20%) and increase in proportion p.p. from 30% up to 50% decelerated (3 vs. 2 weeks) in high BCS groups. High BCS cows received a monensin controlled‐release capsule (CRC) (HC/MO), a blend of essential oils (HC/EO) or formed a control group (HC). Performance parameters and energy status were evaluated in three periods [day (d) ?42 until calving, one until 14 days in milk (DIM), 15 until 56 DIM]. Feed efficiency was 65% and 53% higher in HC/MO than in LC (p < 0.001) and HC groups (p = 0.002) in the second period. Milk fat content was higher in HC/EO (5.60 vs. 4.82%; p = 0.012) and milk urea higher in HC/MO (135 mg/kg) than in LC cows (107 mg/kg; p < 0.001). Increased p.p. levels of non‐esterified fatty acids in serum were found in HC (p = 0.003), HC/MO (p = 0.068) and HC/EO (p = 0.002) in comparison with LC cows. Prevalence of subclinical and clinical ketosis was 54% and 46%, respectively, in HC group. Monensin decreased the prevalence to 50% and 7% respectively. Ruminal fermentation pattern showed higher proportions of propionate (23.43 mol % and 17.75 mol %, respectively; p < 0.008) and lower acetate:propionate ratio (2.66 vs. 3.76; p < 0.001) in HC/MO than HC group. Results suggest that a monensin CRC improved energy status and feed efficiency of transition dairy cows while essential oils failed to elicit any effect.     

Allele-specific polymerase chain reaction diagnostic test for the functional MDR1 polymorphism in dogs

The major multidrug transporter P-glycoprotein (Pgp) contributes to the barrier function of several tissues and organs, including the brain. In a subpopulation of Collies and seven further dog breeds, a 4 base pair deletion has been described in the Pgp-encoding MDR1 gene. This deletion results in the absence of a functional form of Pgp and loss of its protective function. Severe intoxication with the Pgp substrate ivermectin has been attributed to the genetically determined lack of Pgp. An allele-specific polymerase chain reaction (PCR)-based screening method has been developed to detect the mutant allele and to determine if a dog is homozygous or heterozygous for the mutation. Based on this validation, the allele-specific PCR proved to be a robust, reproducible and specific tool, allowing rapid determination of the MDR1 genotype of dogs of at risk breeds using blood samples or buccal swabs.     

Emergence of Echinococcus multilocularis among Red Foxes in northern Germany, 1991--2005

The parasite Echinococcus multilocularis is currently of great concern in Europe because of its spreading behavior, which has public health implications. This study investigates the spatiotemporal distribution of Echinococcus multilocularis in Red Foxes. The infection status of 8459 foxes was sampled from 43 regions in the north German province of Lower Saxony over three investigation periods 1991--1994, 1994--1997 and 2003--2005. Linear empirical Bayesian smoothing within the binomial model was used to produce smoothed choropleth maps. Geostatistical kriging was applied to generate prevalence risk maps. Further geostatistical modeling of the prevalence difference between study periods facilitated spatiotemporal trend investigations. The spatial scan statistic was used for cluster detection analysis. The average prevalence risk for Lower Saxony increased from about 12 to 20% during 1991--2005. Specifically the increases from first to second and to third study periods were estimated by 3.3% (CI 95%: 0.6%-5.9%) and 8.5% (CI 95%: 5.2%-11.8%), respectively. Infections in foxes were clustering and a location stable disease cluster was detected in the south of the province. This study is the first showing evidence for steady emergence of Echinococcus multilocularis in Red Foxes. First cases of human Alveolar Echinococcosis were recorded recently.     

A comparison of immune responses to infection with virulent infectious bursal disease virus (IBDV) between specific-pathogen-free chickens infected at 12 and 28 days of age

Previous studies indicated that the pathogenesis of infectious bursal disease virus (IBDV) may vary depending on the age of the infected chicken. The reason for this difference is not clear, immunopathogenesis studies comparing different age groups are lacking. In the present study the IBDV-immunopathogenesis was compared in 12-day-old and 28-day-old specific-pathogen-free layer-type chickens. Birds were inoculated with the classic virulent strain IBDV-IM. Interestingly, the up-regulation of interferon (IFN)-gamma and interleukin-1beta expression varied between the two IBDV-infected age groups. The cytokine expression pattern was different between IBDV-infected age groups in magnitude and timing not only in bursal tissue and caecal tonsils but also in the spleen. No variations between the different age groups were observed in IBDV-induced bursa lesions, accumulation of intrabursal T cells and macrophages, and systemic stimulation of the release of nitric oxide inducing factors. Furthermore, virus-neutralizing antibody levels were comparable between age groups. Under these experimental conditions, age-related differences were found only for the cytokine patterns but interestingly this did not influence the outcome of the disease with IBDV-IM.     

Bioremediation of a Soil Industrially Contaminated by Wood Preservatives��Degradation of Polycyclic Aromatic Hydrocarbons and Monitoring of Coupled Arsenic Translocation

Two commercially available aerobic bioremediation methods (Daramend® and BioSan) were utilized to study the aerobic biodegradation of polycyclic aromatic hydrocarbons (PAH) and the effect of the simultaneously present arsenic. The soil was collected at an old wood preservation site, and the initial PAH₁₆-concentration was 46 mg/kg, with mainly high molecular weight congeners. The As concentration was 105 mg/kg with low availability as assessed with sequential extraction. To enhance the availability of PAH, the effect of a nonionic surfactant was evaluated. Degradation of both low and high molecular weight PAH was observed; however, after 30 weeks, the degradation was generally low and no treatment was significantly better than the others. The treatments had, on the other hand, an effect on As remobilization, with increased As concentration in the available fraction after treatment. This may be due to both the microbial activity and the presence of anoxic microsites in the soil. The overall efficiency of the biological treatment was further evaluated using the standardized ecotoxicity test utilizing Vibrio fischeri (Microtox®). The toxicity test demonstrated that the bioremediation led to an increase in toxicity, especially in treatments receiving surfactant. The surfactant implied an increase in contaminant availability but also a decrease in surface tension, which might have contributed to the overall toxicity increase.     

Influence of conjugated linoleic acids and vitamin E on milk fatty acid composition and concentrations of vitamin A and α‐tocopherol in blood and milk of dairy cows

The objective of this trial was to investigate the influences of conjugated linoleic acid (CLA ) and vitamin E (Vit. E) and their interactions on fatty acid composition and vitamins in milk (α‐tocopherol, retinol and β‐carotene) as well as on α‐tocopherol in blood of pluriparous cows from week 6 ante partum until week 10 post‐partum (p.p.). We assigned 59 pluriparous German Holstein cows to four treatment groups with the treatment factors CLA and Vit. E at two levels in a 2 × 2 factorial design. Milk fatty acid composition and milk vitamins were analysed on lactation days 7 and 28. α‐tocopherol in blood serum was analysed on days ?42, ?7, 1, 7, 14, 28 and 70 relative to parturition. Milk concentration of α‐tocopherol was influenced by Vit. E (p  < .001) and CLA (p  = .034). Percentage of cis ‐9, trans ‐11 CLA in total milk fat was influenced by treatment with CLA (p  < .001), while for percentage of trans‐ 10, cis ‐12 CLA an interaction between treatment and day (p  = .019), driven by an increase in both CLA groups from day 7 to day 28, was found. Serum ratios of α‐tocopherol to cholesterol were influenced by Vit. E (p  < .001). Results suggest that treatment with CLA during late pregnancy and early lactation is suitable to enhance the proportion of trans‐ 10, cis ‐12 CLA in milk and thereby influencing nutritional properties. As treatment with Vit. E did not have an impact on milk fatty acid composition, it might be possible to increase the antioxidative capacity of the dairy cow without affecting milk properties. Consequently, combined treatment with CLA and Vit. E might elicit synergistic effects on the cow and milk quality by increasing the proportion of CLA in milk fat as well as the excretion of Vit. E and the Vit. E levels in serum.