Fasciola hepatica - monitoring the milky way? The use of tank milk for liver fluke monitoring in dairy herds as base for treatment strategies

In this study 595 lactating cows originating from 31 carinthian farms were investigated in accordance of liver fluke infection using individual and tank milk as well as individual blood and faecal samples. Two commercial ELISAs were used to test the milk and blood serum, and the results were compared with coproscopy and a commercial copro-antigen ELISA. Receiver operating characteristics (ROC) and two-graph operating characteristics (TG ROC) of tank milk results were conducted based on the individual milk to determine the minimum reliable in-herd antibody prevalence for the predominant condition in the investigation area. In 17.8% of the examined individuals located in 64.5% of the farms eggs were detected by coproscopy. The copro-antigen ELISA delivered 13.4% positive individuals from 54.8% of the farms. The milk ELISAs showed 42.7% (Euroclone) and 44.2% (Pourquier) positive cows on 90.3% of the farms. The blood samples were positive in 43% (Euroclone) and 45.2% (Pourquier) of the individuals from 90.3% to 96.8% of the herds, respectively. Based on the milk and the blood an average in-herd prevalence of 30-45% can be assumed. The serum and milk samples delivered correlating results with kappa values between 0.94 and 0.97, whereas the coproscopy and copro-antigen ELISA did not correlate well with the ELISA results. The two different ELISA tests highly correlated on individual and on herd level. Both showed a reliable minimum in-herd prevalence of ～20%, meaning that one fifth of the individuals in a herd have to be positive to obtain a positive bulk tank milk result. In the investigated area a higher in-herd prevalence is expected, therefore the tank milk is useful as a monitoring tool and can be used as a basis for intervention strategies.     

Authentication of organic feed by near-infrared spectroscopy combined with chemometrics: a feasibility study

Organic products tend to retail at a higher price than their conventional counterparts, which makes them susceptible to fraud. In this study we evaluate the application of near-infrared spectroscopy (NIRS) as a rapid, cost-effective method to verify the organic identity of feed for laying hens. For this purpose a total of 36 organic and 60 conventional feed samples from The Netherlands were measured by NIRS. A binary classification model (organic vs conventional feed) was developed using partial least squares discriminant analysis. Models were developed using five different data preprocessing techniques, which were externally validated by a stratified random resampling strategy using 1000 realizations. Spectral regions related to the protein and fat content were among the most important ones for the classification model. The models based on data preprocessed using direct orthogonal signal correction (DOSC), standard normal variate (SNV), and first and second derivatives provided the most successful results in terms of median sensitivity (0.91 in external validation) and median specificity (1.00 for external validation of SNV models and 0.94 for DOSC and first and second derivative models). A previously developed model, which was based on fatty acid fingerprinting of the same set of feed samples, provided a higher sensitivity (1.00). This shows that the NIRS-based approach provides a rapid and low-cost screening tool, whereas the fatty acid fingerprinting model can be used for further confirmation of the organic identity of feed samples for laying hens. These methods provide additional assurance to the administrative controls currently conducted in the organic feed sector.     

Environmental and chemical control of growth and flowering of Chamelaucium uncinatum Schauer

The main factor affecting floral initiation of Geraldton Wax-Flower (Chamelaucium uncinatum) is the photoperiod, while temperature is the major factor affecting flower development. Four weeks of short days (SD) are generally required for obtaining full flowering. The number of flowers produced per plant increases with increasing the number of SD. Under mild temperatures of $\text{20}\text{14°}\text{C}$ (day/night), plants initiated flowers even in long days (LD). However, fewer flowers were produced and on higher nodes as compared to SD plants. Chlormequat promoted flowering under prevailing summer conditions of high temperatures and LD. Under prevailing autumn conditions favourable for flower initiation, LD treatment or weekly sprays with gibberellic acid (GA) reduced the number of flowers per plant. Combined treatment of LD and GA reduced both the flowering percentage and the number of flowers per plant. Discontinuing the LD or the GA treatments caused a resumption of full flower initiation.     

Necropsy of adult cattle

This article presents a brief overview of some examination techniques commonly used during necropsy of adult cattle. A few common diseases and their typical lesions are described and appropriate laboratory techniques to confirm or help deny the roles of specific agents are mentioned.     

Effect of water content and storage temperature of gladiolus corms on flowering

Flowering of Gladiolus grandiflorus was affected by the previous growing conditions and post-harvest handling of the corms. Reducing the storage temperature of the May-harvested corms from 33 to 5 °C caused severe decreases in flowering, whereas a similar treatment given to July- or September-harvested corms did not reduce flowering. A 10% reduction in water content of summer-harvested corms immediately after digging had no deleterious effect on flowering.     

Evidence that resistance to potato leafroll virus accumulation in tetraploidsolarium tuberosum L. is controlled by one or few major genes that are not complementary

Summary Previous investigations into the inheritance of resistance to accumulation of potato leafroll virus indicated a dominant major-gene effect, but the segregation ratios in progenies of crosses were a closer fit to a model involving two complementary genes (both required for resistance and one present in the susceptible parent cultivar, Maris Piper) than to a single gene model. In this study, we tested the complementary gene hypothesis by backcrossing susceptible segregants from one of these progenies to their susceptible parent, Maris Piper. No resistant segregants were found in the five backcross progenies examined, so the complementary gene hypothesis was not supported. There was significant variation between susceptible progeny-members in these backcrosses. The progeny of another, highly resistant parent clone, G. 8107(1), selfed, was also examined: all members were resistant. Whilst there is evidently a dominant major-gene effect involved, this is not the whole picture and there are other unidentified genetic effects.     

Soil Microbial Communities Reflect both Inherent Soil Properties and Management Practices in Wisconsin Potato Fields

Microbial communities in soils provide numerous functions vital to agricultural productivity, and there is growing interest in understanding and manipulating these communities to achieve more sustainable production systems. We investigated microbial communities in potato fields in Wisconsin to determine the extent to which microbial communities were structured by inherent soil properties versus factors under grower control. We found that soil properties, including texture and chemistry, shaped microbial communities at broad levels, determining the diversity and abundance of phyla. Organic versus conventional management, however, correlated with finer scale differences in microbial communities, while crop variety was not associated with microbial community composition in this study. These results suggest that grower practices have the potential to alter microbial communities, but these effects will take place within an existing soil context. Future research is necessary to determine how these patterns in microbial community structure relate to functional outcomes for plant health.     

Feeding Electivity Indices in Surgeonfish (Acanthuridae) of The Florida Keys

Three species of surgeonfish Acanthurus coeruleus (blue tang) (Block and Schneider), A. bahianus (ocean surgeonfish) (Castelnau), and A. chirurgus (doctorfish) (Block) were captured in the waters of the Florida Keys (24°03N, 81°40W). In total, 39 of these fish were captured between March and December of 1999. Items found in the stomachs of these fish were identified and analyzed for percent occurrence. These values were compared to percent occurrence values of the same items from random bottom transects taken at the point of capture to quantify any forage selectivity or avoidance behavior of these fish. A. bahianus selected for sand and chlorophytes and avoided phaeophytes. A. chirurgus also showed selection for sand and chlorophytes, while 58% of those sampled selected for phaeophytes and 42% avoided them. A. coeruleus avoided sand and selected for rhodophytes and chlorophytes. Phaeophytes were also selected for in 80% of A. coeruleus sampled. Understanding food preferences of free-ranging Florida surgeonfish may provide insight to improve nutritional management of captive herbivorous reef fish.