Genetic differentiation of infected from vaccinated animals after implementation of an emergency vaccination strategy against classical swine fever in wild boar

Oral emergency vaccination against classical swine fever is a powerful tool to control disease outbreaks among European wild boar and thus to safeguard domestic pigs in affected regions. In the past, when virus detection was mainly done using virus isolation in cell culture or antigen enzyme-linked immunosorbent assays, modified live vaccine strains like C-strain "Riems", were barely detectable after oral vaccination campaigns. Nowadays, the use of highly sensitive molecular techniques has given rise to an increase in vaccine virus detections. This was also the case during the 2009 outbreak among German wild boar and the subsequent vaccination campaigns. To guarantee a rapid differentiation of truly infected from C-strain vaccinated animals, a combination of differentiating multiplex rRT-PCR assays with partial sequencing was implemented. Here, we report on the rational and use of this approach and the lessons learned during execution. It was shown that positive results in the recently developed vaccine strain (genotype) specific rRT-PCR assay can be taken as almost evidentiary whereas negative results should be confirmed by partial sequencing. Thus, combination of multiplex rRT-PCR assays as a first line differentiation with partial sequencing can be recommended for a genetic DIVA strategy in areas with oral vaccination against classical swine fever in wild boars.     

Untersuchungen zum notwendigen Maß bei der Anwendung von Pflanzenschutzmitteln in Winterweizen in den Jahren 2004 bis 2016

In order to provide recommendations for future cropping systems with regard to the necessary minimum of pesticide use, a long-term field trial at the field site in Dahnsdorf of the Julius Kühn-Institute was conducted in the years 2004 to 2016 to investigate possible reduction of pesticides, taking into account the general principles of integrated pest management (Strategies to reduce the use of plant protection products). Two winter wheats (WW1 and WW2) were part of the crop rotation with six components and different quality classes (A wheat (WW1) and E wheat (WW2)) and resistance levels to important wheat pathogens. In all years, herbicides and fungicides were needed to control weeds and fungal pathogens due to the excess of the control threshold. Insecticides were only necessary in two years. When considering the treatment frequency index (TFI), the mean overall TFI varied with 2.6 in WW1 and 3.5 in WW2, but was significantly lower compared to practice. There were also differences in the mean fungicide TFI of the two crop rotation elements with 1.1 in WW1 and 1.6 in WW2 due to their different resistance level to important fungal pathogens. The same is true with regard to the herbicide TFI with of 1.1 in WW1 and 1.3 in WW2. The treatments in the strategies 2, 3 and 4 mostly resulted in significantly higher yields compared to the non-chemical strategy 1, which can be attributed to the strong weed and fungal infestations in strategy 1 and the good efficacy of the used plant protection products. The tended differences between strategy 2 with a situation-related application rate and the 25 and 50% reduced application rates in strategies 3 and 4, respectively, were not significant. A reduced application rate showed no negative long-term effects on weed emergence even after 13 years, but increased emergence numbers in strategies with reduced herbicide use. The results show that plant protection products savings are possible without significantly reducing yields. However, this requires a high level of human resources for monitoring and scoring the consistent observance of the principles of integrated pest management, such as the consideration of good crop rotation, the cultivation of resistant cultivars and the optimally coordinated treatments after the control threshold has been exceeded.     

In-mouth amylase activity can reduce perception of saltiness in starch-thickened foods

Sensory scores for saltiness and thickness obtained for savory liquids thickened with starches or the nonstarch hydrocolloid hydroxypropylmethyl cellulose (HPMC) were correlated with the panelists' amylase activity. Although higher enzyme activities were linked to lower thickness scores for systems thickened by starch, they were also associated with a decreased taste perception, particularly for starches retaining a granular structure after gelatinization (wheat and modified waxy maize). Microscopic evidence showed that the enzyme can disrupt such structures, and this is associated with a decreased mixing efficiency with water and consequently a reduced transport of tastant (sodium) to the saliva (aqueous) phase and to the taste buds. This explains the lower saltiness scores for subjects with higher amylase activity, even if they are associated with a lower perceived thickness.     

Effects of melatonin on oocyte developmental competence and the role of melatonin receptor 1 in juvenile goats

Melatonin enhances in vitro embryo development in several species by improving the oocyte developmental competence during in vitro maturation (IVM). Melatonin has a wide range of actions, from scavenging reactive oxygen species (ROS) to regulating gene expression, and it can also act by way of melatonin receptors. The aim of this study was to determine the mechanism of action of melatonin during the IVM of juvenile goat oocytes and the role of the membrane receptors. Melatonin receptor 1 was immunolocalized in cumulus cells and oocytes before and after 24 hr of IVM. The effect of melatonin on oocyte developmental competence was tested in three experimental IVM groups: (a) control, (b) 10^?7 M melatonin, and (c) 10^?7 M melatonin +10^?7 M luzindole (an inhibitor of both melatonin receptors). After IVM oocytes were assessed for ROS levels, mitochondrial activity, adenosine 5′‐triphosphate (ATP) concentration and relative gene expression (ACTB, SLC1A1, SOD1, GPx1, BAX, DNMT1, GCLC and GDF9). IVM‐oocytes were in vitro fertilized and cultured under conventional conditions. Blastocyst rate and quality (differential cell count) were assessed at 8 days post‐fertilization. Melatonin decreased ROS levels, increased mitochondrial activity and ATP content and increased blastocyst quality compared to control group (55.8 vs. 30.4 inner cell mass ICM, p < 0.05). There was no effect on the relative gene expression due to treatment with melatonin. In conclusion, we have showed that melatonin improves oocyte developmental competence in juvenile goats by reducing ROS levels and improving mitochondrial activity.     

Nachernte-Behandlung von Äpfeln mit Calciumchlorid

From 2003 to 2006 the efficacy of post-harvest dips in calcium chloride solution was investigated for apples. Aim of these investigations was to find out the influence of different factors on the Ca-uptake of apples after harvest. The Ca-uptake of the fruit was influenced by following factors:

• the calcium chloride concentration of the dip solution,
• the duration of the dip,
• the duration of fruits' wetting,
• the apple cultivar,
• the addition of a wetting agent and
• the maturity of the fruit.

To get an appreciable Ca-uptake, the addition of a wetting agent is necessary. For a dip time of two minutes calcium chloride concentrations of 7 or 7.5% are needed. Apparently injuries of the apple skin don't appear. An elongation of the dip time or the duration of wetting increased the Ca-uptake. Cultivar and maturity of the fruit affect the Ca-uptake. The increase of the Ca-content can proved only close to the apple skin (skin to 2?cm depth).     

Rapid prediction of gross energy and utilizable energy in cereal food products using near-infrared reflectance spectroscopy

Near-infrared (NIR) spectroscopy has been used in foods for the rapid assessment of several macronutrients; however, little is known about its potential for the evaluation of the utilizable energy of foods. Using NIR reflectance spectra (1104-2494 nm) of ground cereal products (n = 127) and values for energy measured by bomb calorimetry, chemometric models were developed for the prediction of gross energy and available energy of diverse cereal food products. Standard errors of cross-validation for NIR prediction of gross energy (range = 4.05-5.49 kcal/g), energy of samples after adjustment for unutilized protein (range = 3.99-5.38 kcal/g), and energy of samples after adjustment for unutilized protein and insoluble dietary fiber (range = 2.42-5.35 kcal/g) were 0.053, 0.053, and 0.088 kcal/g, respectively, with multiple coefficients of determination of 0.96. Use of the models on independent validation samples (n = 58) gave energy values within the accuracy required for U.S. nutrition labeling legislation. NIR spectroscopy, thus, provides a rapid and accurate method for predicting the energy of diverse cereal foods.