The use of a Giardia vaccine as an immunotherapeutic agent in dogs.

Dogs (n = 13), which had failed to be cured of giardiosis following chemotherapeutic measures, were treated with a Giardia vaccine (2-3 injections). Clinical signs resolved between 16 and 42 days postvaccination and cessation of fecal cyst shedding was between 21 and 70 days. Vaccination is a potential method of treating giardiosis in dogs.     

An evaluation of the pesera soil erosion model and its application to a case study in Zakynthos, Greece

Abstract. The Pan‐European Soil Erosion Risk Assessment (pesera ) model was evaluated using existing soil erosion data collected under various types of climate, vegetation, landscape and soil conditions. The data used represent a variety of typical Mediterranean land uses such as winter wheat, vines, olives and bare, stony land prevailing in hilly areas. Using this data, the model was calibrated for sediment transport by overland flow and results compared to measured soil erosion values from runoff plots and a watershed on a monthly basis. The performance of the model was assessed statistically, showing that it can be satisfactorily used for predicting soil erosion rates under the conditions included in the study. The overall model estimate including all the available experimental data was 0.69 t ha^?1 yr^?1 with a maximum error of 1.49 t ha^?1 yr^?1. After validation, the model was applied to a small watershed (60 ha) of great ecological importance for the sea turtle Caretta caretta. For this purpose, soil and vegetation maps were compiled from all the necessary data for applying the model. The model was run for three years using daily data from an existing nearby meteorological station. The predicted and measured soil erosion rates for a 7‐month period were 0.31 t and 0.18 t, respectively. Application of the model to each mapping unit showed the over‐riding importance of land use for sediment generation under the given climatic conditions. Bare land, occupying 5.5% of the watershed area, generated up to 69% of the total sediments estimated for the watershed. It is concluded that the pesera model can be used as a regional diagnostic tool under a range of soil, topographic and climatic conditions for identifying the best land use type and vegetation cover to protect hilly areas from soil erosion. The calculated overall root mean square error for the model is 0.06 t ha^?1 yr^?1, compared to a soil erosion rate of 0.04 t ha^?1 yr^?1, which can be tolerated for protecting the area for the sea turtle.     

Flow cytometric analysis of intracellular complexity and CD45 expression for use in rapid differentiation of leukocytes in bovine blood samples.

OBJECTIVE: To develop an efficient and reliable method that accurately differentiates bovine lymphocytes from monocytes in leukograms. SAMPLE POPULATION: Blood samples from 30 healthy cows and 1 calf with bovine leukocyte adhesion deficiency. PROCEDURE: Flow cytometric analysis of intracellular complexity and CD45 expression on bovine leukocytes was compared with results for conventional light microscopy methods. Verification of leukocyte subpopulations determined by intracellular complexity and CD45 expression was conducted, using 2-color phenotypic analysis with selected monoclonal antibodies. RESULTS: The CD45 and side-scatter properties of bovine leukocytes clearly differentiated cell types, including neutrophils, eosinophils, monocytes, and lymphocytes. CONCLUSIONS AND CLINICAL RELEVANCE: This is a rapid assay that is simple to use. More importantly, it is more accurate than the conventional method that involves the use of blood slides and light microscopy, because of the ability of the assay to readily distinguish bovine monocytes and lymphocytes. Rapid preparation of samples and short analysis times allow for efficient and reliable examination of a large number of samples, and the task of viewing slides by light microscopy is eliminated. The labor-savings benefit of this procedure is most apparent in research environments that require frequent processing of batches of blood samples.     

Feeding Frequency Affects Growth, Not Fillet Composition, of Juvenile Sunshine Bass Morone chrysops×M. saxatilis Grown in Cages

Abstract.— In an effort to feed sunshine bass Morone chrysops × M. saxatilis efficiently, promote optimal growth, and reduce labor costs associated with feeding, sunshine bass were grown in cages and fed one of four feeding frequencies: once/d, twice/d, once every other day (I X/EOD), and twice every other day (2X/EOD) for 21 wk. Juvenile sunshine bass were fed a commercial floating diet containing 40% protein and 11.5% lipid. One hundred fish were hand-counted and stocked into each of 12 3.5-m³ cages with three replications per treatment. At the conclusion of the study, percentage weight gain of sunshine bass fed twice/d was significantly (P < 0.05) higher (1,850%) compared to fish fed all other feeding frequencies. Specific growth rate (SGR) of fish fed twice/d was significantly higher (2.1%/d) compared to fish fed all other feeding regimes, while fish fed once/d had a higher SGR (2.0%/d) compared to fish fed I X/EOD (1.6%/d) and 2X/EOD (1.8%/d). Percentage survival was not significantly different (P > 0.05) among all treatments and averaged 70.4%r. Feed conversion ratio (FCR) of fish fed twice/d was significantly higher (2.40) compared to fish fed all other feeding regimes. Percentage fillet weight of fish fed twice/d was significantly higher (27.8%) compared to all other treatments. Percentage moisture, protein, lipid, and ash in fillet were not significantly different among all treatments and averaged 75.7%, 19.4%, 3.5%, and 1.2%n, respectively (wet-weight basis). Based upon data from the present study, it appears that producers growing juvenile sunshine bass in cages may want to feed fish twice daily. This feeding regimen allows for higher growth rates, without adverse effects on body or fillet compositions. However, economic analysis needs to be conducted to determine if feeding twice/d is profitable.     

Genetic diversity of herbicide-resistant and -susceptible Avena fatua populations in North Dakota and Minnesota

Genetic diversity within and among 20 herbicide-resistant (HR) and 16 herbicide-susceptible (HS) Avena fatua multi-field populations was determined using 82 polymorphic loci resulting from two intersimple sequence repeat (ISSR) primers and one long-primer random amplified polymorphic DNA (LP-RAPD) primer. Collections from the Red River Valley of North Dakota and Minnesota, sampled in 1964 and 2000, represented A. fatua populations before and after intensive exposure to herbicides. A 1995 collection from south-west North Dakota represented A. fatua exposed to low herbicide selection. Despite differences in years of herbicide exposure among collections, both HR and HS populations from every collection maintained nearly similar levels of ISSR and RAPD diversity. Genetic differentiation among populations (G_ST) varied from 11% to 13% among HR populations and from 9% to 16% among HS populations, indicating that 84–91% of total variation remained within HS or within HR populations. Minimal difference in gene diversity between HR and HS is consistent with multiple origins of resistance, where HR A. fatua most likely evolved from diverse founding individuals.     

Histopathological and hematological findings in myeloid leukemia induced by a new feline leukemia virus isolate

Myeloid leukemia was induced by a new feline leukemia virus isolate FeLV-AB/GM-1 in a high proportion of cats. The latency period was short. Three to 5 weeks after infection early changes were detectable in the bone marrow, and cats developed leukemia 5 to 8 weeks after infection. The results of the present histological and cytological studies suggested that there were two stages in the development of leukemia. The first stage appeared to be equivalent to the syndrome of bone marrow dysplasia or preleukemia which, however, converted rapidly to leukemia. Cytopenia(s) were the main hematological findings in all preleukemic and leukemic cats. White blood cell counts were low or normal, but the number of leukemic and abnormal cells increased in the peripheral blood with the progression of the disease. This reliable model system lends itself to further studies to elucidate the pathogenesis of myeloproliferative disorders.     

Survival of Leptosphaeria maculans in soil on residues of Brassica napus in South Australia

The survival of Leptosphaeria maculans , which causes phoma stem canker (blackleg), on oilseed rape residues ( Brassica napus ) in South Australia was investigated. Using a quantitative polymerase chain reaction (PCR) assay for L. maculans DNA, the pathogen was mainly detected in the upper 5 cm of the soil profile, including residues on the soil surface. As the size of organic matter particles in the soil decreased, so did the quantity of L. maculans detected in them. To obtain representative data for a field, at least 30 subsamples needed to be collected over the 0·81 ha area studied. In a survey of 49 commercial fields in South Australia, most L. maculans was detected in fields 1 year after oilseed rape had been grown, with less detected after 2 years and negligible amounts 3 years or more after cropping. The diagnostic DNA-based assay for L. maculans reduced the time and cost of studying L. maculans survival in soil and increased the sensitivity and accuracy of results compared with estimates of propagule number of colony-forming units on a semiselective medium.     

Nutrient digestibility of angling baits for carp, Cyprinus carpio, with implications for groundbait formulation and eutrophication control

Abstract  To evaluate the suitability of angling groundbaits as a fish feed and the potential for nutrient loss, the macronutrient digestibility of four groundbaits was investigated in carp, Cyprinus carpio L., using a sieving method of faeces collection and chromic oxide. Apparent digestibility coefficients (ADCs) of protein and lipids were >80% for all angling baits. ADCs of nitrogen-free extracts and phosphorus (P) differed significantly between the test diets, probably because of divergent feed compositions and ingredient treatments. The generally high digestibility estimates indicated that fish feeding on angling groundbait will benefit from this food source. The differences in nutrient digestibility suggested that type of groundbait and ingredient used will have a major effect on potential eutrophication and fish production caused by groundbaiting. The principle of groundbaits to protect the environment should be to minimise the P-content of the groundaits and maximising P-digestibility and P-retention efficiency.