Distribution of prion protein genotypes in breeds of sheep in New Zealand

AIM: To use an established high through-put genotyping procedure to gain an estimate of the frequency of alleles of the prion protein (PrP) gene in some common sheep breeds in New Zealand.

METHODS: Using a genotyping procedure based on matrix-assisted laser desorption ionisation-time of flight (MALDI-TOF), DNA samples from 3,024 sheep from New Zealand, including breeds such as Romney, Texel, Coopworth, Merino and mixedbreed, were isolated, genotyped and the results analysed.

RESULTS: The 15 scrapie genotypes commonly reported, and derived from the five commonly reported allelic variants (ARR, ARQ, AHQ, ARH and VRQ), were all observed in the samples analysed. The estimates were indicative of the frequencies in the population of alleles present in breeds of sheep in New Zealand. There was a significant difference between the frequencies of alleles between breeds, but the ARQ, followed by the ARR allele, were, except in Carwell sheep, the most common alleles present.

CONCLUSION: This study gave an indication of the percentages of PrP gene alleles in sheep in New Zealand, including data previously unreported from breeds in this country. It is of interest because of the relatively large size of the sheep population in New Zealand compared with many countries, and it provides some useful information on the genetic susceptibility or resistance of the sheep population in New Zealand to scrapie. The frequencies of the alleles can be different for an individual breed compared between countries.     

Influence of comb parameters on picking properties for chamomile flowers (Matricaria recutita)

Tools in the form of a comb are generally used to harvest chamomile flowers. The combs can be hand-operated or machine-based. To achieve good picking quality and low losses, the comb parameters have to be optimized. In this paper, the influence of comb thickness (0.5 mm, 1.0 mm and 2 mm) and the shape of the gap between the tines (3 variants) on picking force and remaining stalk length was investigated for German chamomile (Matricaria recutita) under lab conditions. To ensure that the stalks glide along the gap to the ground of the picking blade, the inclination angle was adjusted to be 45° from the blade plane in the direction of movement. For each of the 9 variants, 100 breaking tests were performed. To estimate the breaking force, a specific tensile force measuring instrument was used. The mean breaking strength of the stalks for the investigated 9 variants ranged from 3.62 N mm⁻² to 4.66 N mm⁻². In about 50% of the tests, the comb parameters had no influence because stalks broke outside of the contact point with the comb at the weakest section of the stalk. In conclusion, the picking quality of involved test blades was partially influenced by the thickness of the blade, the shape of the gap between the teeth and substantially by the strength of the individual chamomile stalks.     

Soil compaction and stress propagation after different wheeling intensities on a silt soil in South-East Norway

The objective of this study was to evaluate the effect of wheeling with two different wheel loads (1.7 and 2.8?Mg) and contrasting wheeling intensities (1x and 10x) on the bearing capacity of a Stagnosol derived from silty alluvial deposits. Soil strength was assessed by laboratory measurements of the precompression stress in topsoil (20?cm) and subsoil (40 and 60?cm) samples. Stress propagation, as well as elastic and plastic deformation during wheeling were measured in the field with combined stress state (SST) and displacement transducers (DTS). We also present results from soil physical analyses (bulk density, air capacity, saturated hydraulic conductivity) and barley yields from the first two years after the compaction. Although the wheel loads used were comparatively small, typical for the machinery used in Norway, the results show that both increased wheel load and wheeling intensity had negative effects on soil physical parameters especially in the topsoil but with similar tendencies also in the subsoil. Stress propagation was detected down to 60?cm depth (SST). The first wheeling was most harmful, but all wheelings led to accumulative plastic soil deformation (DTS). Under the workable conditions in this trial, increased wheeling with a small machine was more harmful to soil structure than a single wheeling with a heavier machine. However, the yields in the first two years after the compaction did not show any negative effect of the compaction.     

Quantitative comparison of different methods for the detection of Toxocara canis eggs in sand samples

Eleven techniques for recovering helminth eggs from sand and soil samples were tested for efficiency and suitability for routine use. The tests were done under standardized conditions on sand samples of 100 g contaminated experimentally with 10, 100 or 1,000 eggs of Toxocara canis. Best results were achieved by a flotation-sedimentation technique (Stoye and Horn, 1986) and by a sieving method (K?hler et al., 1980), showing mean recovery rates of 43.1% and 41.4%, respectively. All other methods tested, mean recovery rates were about 20% or less.     

Effect of dietary fumonisin B1 on certain immune parameters of weaned pigs

Only few data are available on the effect of fumonisins on the immune response. The aim of the present study was to examine whether dietary fumonisin B1 (FB1) has any effect on the humoral and cellular immune response in weaned pigs, depending on the dose and the time of toxin exposure. Fusarium moniliforme fungal culture was added to the experimental animals' diet to ensure an FB1 intake of 1, 5 and 10 ppm (first experiment) or 100 mg per animal per day (second experiment). The control animals were fed a toxin-free diet. In order to determine the immune response, the animals were vaccinated against Aujeszky's disease with inactivated vaccine (Aujesping K, Phylaxia-Sanofi, Budapest, Hungary). Specific and nonspecific in vitro cellular immune response was measured by the lymphocyte stimulation test (LST) induced by PHA-P, Con A, LPS and inactivated suspension of the Aujeszky's disease virus. Humoral immune response, e.g. specific antibody titre, was measured by the virus neutralisation (VN) test. None of the immunological parameters examined showed significant differences between groups. It could be concluded that fumonisin B1 had no significant effect on the humoral and cellular specific and nonspecific immune response when fed in a high dose (100 mg/animal/day for 8 days) or in a low concentration even for a longer period (1, 5 and 10 ppm for 3-4 months).     

Influence of preshipment management on the adrenal response of beef calves to ACTH before and after transit

The influence of preshipment management, transit (965 km) and postshipment management upon the ability of the adrenal gland to respond to exogenous adrenocorticotropic hormone (ACTH) was evaluated in 60 beef calves (47 bulls and 13 steers). Adrenal response to ACTH treatment was quantified before shipment (PRE), about 24 h (POST) and 3 wk after transit (3 WK). Calves were assembled for 4 or 10 d before shipment and fed either a hay or a high energy diet (HE). The area under the plotted curve for the plasma corticoid concentration response to ACTH was used as an adrenal response test (ART). The feeding of hay during the first 4 d of assembly resulted in a greater (P less than .05) PRE ART value than feeding of the HE diet, but after 10 d of assembly, the ART was similar for animals on the two diets. The ART at 24 h after transit was similar to that before shipment. The HE group had a greater (P less than .05) ART than the hay group 3 wk after arrival, however, values were dependent upon postshipment management. Placement of calves on winter wheat pasture soon after arrival resulted in greater ART (P less than .05) values after the 3 wk recovery period than for calves that grazed native range for 10 or 20 d before grazing winter wheat pasture. These data indicate that the ability of the adrenal gland to respond to ACTH is increased at preshipment if the assembly period is 4 d compared to 10 d and the adrenal response at 3 wk after arrival is greater if a HE diet is fed during assembly instead of hay.     

Brucella proteomes--a review

The proteomes of selected Brucella spp. have been extensively analyzed by utilizing current proteomic technology involving 2-DE and MALDI-MS. In Brucella melitensis, more than 500 proteins were identified. The rapid and large-scale identification of proteins in this organism was accomplished by using the annotated B. melitensis genome which is now available in the GenBank. Coupled with new and powerful tools for data analysis, differentially expressed proteins were identified and categorized into several classes. A global overview of protein expression patterns emerged, thereby facilitating the simultaneous analysis of different metabolic pathways in B. melitensis. Such a global characterization would not have been possible by using time consuming and traditional biochemical approaches. The era of post-genomic technology offers new and exciting opportunities to understand the complete biology of different Brucella species.     

Retrospective study of Old World screwworm fly (Chrysomya bezziana) myiasis in 59 dogs in Hong Kong over a one year period

This retrospective study examined the case records of Old World screw-worm fly myiasis in dogs in Hong Kong's New Territories. Myiasis due to OWSWF was identified and treated in 59 dogs at our clinic over a period of 1 year. Signalment, causes of initial wound, and treatments implemented, are reported. All cases recovered from myiasis with a combination of larvae removal and wound debridement, antibiotics, and topical and systemic insecticides. Whilst this parasite is currently exotic to Australia, much of the country is environmentally suitable (tropical and subtropical) for establishment of OWSWF.     

Effects of Gonadotrophin Releasing Hormone Administration on the Pituitary-Ovarian Axis in Anoestrous vs Ovariectomized Bitches

The aim of this study was to determine the effects of gonadotrophin releasing hormone (GnRH) administration on the plasma concentrations of reproductive hormones in intact and ovariectomized (OVX) bitches. Therefore, blood samples were collected at multiple times before and after the administration of 10 microg/kg GnRH (Fertagyl)) for the determination of the plasma concentrations of luteinizing hormone (LH), oestradiol, progesterone and testosterone in six anoestrus and in six OVX bitches. The mean plasma LH concentrations before and 60 min after GnRH administration were significantly lower in the anoestrous bitches than in the OVX bitches. In both groups GnRH administration resulted in a significant increase in the plasma LH concentration. The highest plasma LH concentrations were found at 10 min after GnRH administration and these values did not differ significantly between the two groups. Only in the anoestrous bitches a significant increase in plasma oestradiol concentrations was found after GnRH administration and these values were significantly higher than those in the OVX bitches. The plasma concentrations of progesterone and testosterone were low (close to or below the limit of quantitation) both before and after GnRH administration and the differences between anoestrous and OVX bitches were not significant. It can be concluded that (i) basal plasma LH concentration is significantly higher in OVX bitches than in anoestrous bitches, (ii) plasma LH concentration increases after GnRH administration in both anoestrous and OVX bitches, (iii) GnRH administration causes a significant rise in plasma oestradiol concentration only if ovarian tissue is present and (iv) measurement of plasma progesterone and testosterone concentrations before and after GnRH administration does not aid in distinguishing between anoestrous and OVX bitches. The results of this study may provide a basis for the diagnosis of remnant ovarian tissue and verification of neuter status in the bitch.