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An outbreak of tuberculosis among bovines and pigs caused by Mycobacterium caprae is described in this paper. After tuberculin skin tests with bovine purified protein derivates (PPD) six cattle and one sow, own by a small family farm, tested positive whilst three pigs were suspected in 2004. All animals were euthanised and checked for gross pathological lesions. Generalised lesions were found in five cattle and two sows; however one calf and two gilts had lesions that were localised in the submandibular lymph nodes. Mycobacteria were isolated from tissue samples of six cattle and four pigs. Mycobacterial isolates were identified using classical biochemical tests and molecular methods (PCR, GenoType MTBC) as M. caprae. Mycobacterial Interspersed Repetitive Unit (MIRU) typing of isolated mycobacteria showed an identical number of repeats in 12 different loci. Results of the research confirmed the domination of M. caprae among infected cattle in Croatia; however this paper was the first to confirm a case of M. caprae in pigs. The source of the infection was not found.

Observations of the beech assimilatory apparatus in different levels of a model tree were realised from 1993 to 1999 in a research demonstration plot situated in Poľana. Different observations of the natural ecosystem condition were carried out. A model beech tree was chosen and marked as No. 228 for the above-mentioned analyses. The different ecophysiological and morphological characteristics of beech leaves were analysed in three (or two) tree crown levels. The results confirmed significant differences in these characteristics in dependence on three crown levels of mature beech tree. The differences in the mentioned characteristics were also shown in the course of particular years of research. In this paper we have presented the results of analysed beech leaves, their average maximum length, width, their average area, thickness, chlorophyll fluorescence during the research period.

Frost cracks which originated in birch due to bending during long-term icing in winter 1995/1996 became the place of entrance for the attack of birch stems by Piptoporus betulinus (Bull. ex Fr.) Karst. and subsequently for one of the causes of birch stand disintegration in the Krušné hory Mts. The hypothesis is substantiated on the basis of regularities of the frost crack dispersion in the stem profile, frequency of occurrence related to the stand age, altitude and cardinal points. The number of frost cracks increased with the transect profile altitude 700-850 m. One crack on the birch stem predominated (73%) while the higher number of frost cracks occurred at altitudes > 800 m. In stands younger than 20 years, frost crack damage was higher (34-47%) than in older stands (14%). Frost cracks occurred in the lower part of stems with the highest bending stress.

Rural villages are the sole subjects in rural area which integrate all elements acting in the rural area to one functional whole. They can be therefore taken as the pivotal element of rural development. The research was done in 2004 and was based on the search for rural villages' characteristics and exploration of the elements of regional differentiation. The project results from the presumption of difference between the rural villages given by their size, location in specific areas or on exposed roads, distance from civic centers etc. It is supposed that these characteristics have specific and significant connections with such phenomenon as the level of unemployment, the level of civic and technical facilities in villages, the activity of inhabitants and the village itself, etc. The challenge was to define problem characteristics of rural areas, which mirror significant regional differences, structure and interconnectedness of these differences and their importance for future regional development. Interdependence of particular indicators was explored by statistical evaluation.

The possibility of the application of near-infrared spectroscopy to the analysis of the selected parameters of quality of the dairy products was followed. The contents of solids and fat, as well as pH in yoghurts (also the titrable acidity), milk semolina, and milk rice were determined. The samples were analysed by reference methods and by FT NIR spectroscope at integrating sphere within reflectance mode in the wavelength range of 10 000-4 000 cm^-1 with 100 scans. To develop the calibration model for the components examined, the partial least squares (PLS) was used and this model was validated by full cross validation. The highest correlation coefficients were found with yoghurt: 0.998 (solids), 0.989 (fat), 0.875 (pH) and 0.989 (titrable acidity), with milk semolina: 0.967 (solids), 0.983 (fat) and 0.992 (pH), and with milk rice: 0.987 (solids), 0.990 (fat) and 0.852 (pH). The results of this study showed the availability of NIR spectroscopy for a quick and non-destructive analysis of the dairy products.

The objectives of the paper were to evaluate carcass value in reared gilts on the basis of carcass analysis during the station test of purebred progeny of pigs and ultrasonically with Sonomark-100 or Piglog-105 instruments in the framework of valid methodology for performance testing, and to verify a pos-sibility of prediction of backfat thickness and/or average daily weight gain since birth and lean meat content of gilts as the elements of objectification for the evaluation of their body condition. In total 54 gilts of two breeds were evaluated: the dam breed Czech Large White and the sire breed Czech Large White - sire line. Four-parameter Richards function was used for growth evaluation. The regression function y = 63.870 - 0.447 bt₁ - 0.510 bt₂ + 0.128 MLLT was applied in ultrasonic instruments for the calculation of lean meat content. We calculated linear regression functions for the conversion of performance testing parameters (gain from birth, average backfat thickness and lean meat content) from live weight on the day of measurement per live weight declared during selections in gilts.

Two experiments were conducted to investigate the effects of dietary crude protein level and degradability on milk urea nitrogen (MUN) content. In experiment 1, twelve multiparous lactating cows averaging 176 days in milk were divided according to DIM and milk production into three 4 × 4 Latin squares with four 2-week periods. Cows were fed four diets with different crude protein levels (13.0, 14.0, 15.0, and 16.0%, DM basis) with isocaloric, respectively. Crude protein levels had a low effect on milk yield and composition (P > 0.05), but a significant effect on MUN content. There were significant differences in the MUN content of cows fed either of the two diets (P < 0.01). In experiment 2, fifteen multiparous Holstein dairy cows averaging 91 days in milk were classified according to DIM and milk production into five 3 × 3 Latin squares with three 3-week periods. Cows were fed one of the three isocaloric and isonitrogenous diets with RUP being 30.8%, 36.2%, and 41.6% (CP basis), respectively. Milk yield, milk composition, and MUN content were not significantly affected by protein degradability, and there were no significant differences between any two dietary treatments (P > 0.05). These results indicated that MUN might be used as a parameter to monitor the change in dietary protein levels.

In three test years an assortment of 15 varieties of vegetable pepper (Capsicum annuum L.) were grown in field conditions to study experimentally some of their morphological and biological properties. Mean plant height ranged from 435.7 mm (cv. Lastočka) to 636.7 mm (cv. Srbská). The smallest fruits had cultivars Čerešňová and Kecskeszarv with the weight of 4.86 g and 17.68 g. Average weight was the highest at varieties Pola kapia (92.23 g) and Melišor (91.92 g). The biggest length of mature leaves over 100 mm was measured at varieties Dolmy, Podarok Moldavy and Tuba; the smallest leaves according to length and width had variety Čerešňová. The mean vitamin C content in fruits about 2,000 mg/kg at green mature stage was found in cv. Bohatýr, Čerešňová and Podarok Moldavy. The highest vitamin C content in red fruits was analyzed at cv. Čerešňová (2,551.0 mg/kg) and Lastočka (2,422.2 mg/kg). Other observed characteristics were colour, shape and taste of fruits, colour of leaves and fruit wall thickness.

The second part of the paper summarizes results of an institutional research aimed at the determination of physical and mechanical properties of different sets of plywood sheets pressed under different conditions. The first part dealt with the determination of compressibility or values of decreasing the thickness of pressed plywood sheets. In this second part, results are summarized of the analysis of physical and mechanical properties of the set of whole-beech plywood sheets of the nominal thickness of veneers amounting to 1.5 mm. The plywood sheets were manufactured as seven-ply and urea-formaldehyde resin DUKOL S was used for their production. The sheets were pressed using a pressure of 1.5 and 1.7 MPa. Following parameters were analyzed: moisture, density, bending strength, MOE in bending and shear strength.

Forest soil acidification and depletion of nutrient cations have been reported for several forested regions in North America, predominantly in the eastern United States, including the northeast and in the central Appalachians, but also in parts of southeastern Canada and the southern U.S. Continuing regional inputs of nitrogen and sulfur are of concern because of leaching of base cations, increased availability of soil Al, and the accumulation and ultimate transmission of acidity from forest soils to streams. Losses of calcium from forest soils and forested watersheds have now been documented as a sensitive early indicator and a functionally significant response to acid deposition for a wide range of forest soils in North America. For red spruce, a clear link has been established between acidic deposition, alterations in calcium and aluminum supplies and increased sensitivity to winter injury. Cation depletion appears to contribute to sugar maple decline on some soils, specifically the high mortality rates observed in northern Pennsylvania over the last decade. While responses to liming have not been systematically examined in North America, in a study in Pennsylvania, restoring basic cations through liming increased basal area growth of sugar maple and levels of calcium and magnesium in soil and foliage. In the San Bernardino Mountains in southern California near the west coast, the pH of the A horizon has declined by at least 2 pH units (to pH 4.0-4.3) over the past 30 years, with no detrimental effects on bole growth; presumably, because of the Mediterranean climate, base cation pools are still high and not limiting for plant growth.

ThearticledescribesthelayoutofplantproductionandlivestockdensityintheCzechRepublicin2003 according to a sample survey of the Czech Statistical Office.Theproductionorientationof agriculturalenterprisesis definedas a small amount of market products that represent the predominant part of revenues. Grain crops, pork meat, milk and non-food crops represent the production orientation of Czech agriculture. Thesecommoditiesrepresentmorethan70%oftotal agricultural production in the Czech Republic. In this article, the authors have attempted to definearegionalclassification according to production orientation of agricultural enterprises and intensity of agricultural production.

The extracts of pods of West African black pepper, Piper guineense, at 5, 10 and 20% (w/v), were applied at two, four and six weekly schedules to control the legume flower bud thrips, Megalurothrips sjostedti on flowers of cowpea, Vigna unguiculata. The trials were conducted for 2 years under rain fed conditions in the northern Guinea savanna region of Nigeria. The results showed that the M. sjostedti population was significantly controlled on treated plots compared with the untreated check in both years. The extracts at the 20 and 10% rates and with six or four weekly applications significantly (P < 0.05) reduced thrips pressure on cowpea flowers, were better than the 5% extract at all spraying schedules, and had the same efficacy as the synthetic insecticide treatment. Pod density per plant was significantly higher (P < 0.05) on plots treated with the 20% extract at six or four weekly applications compared to other extract rates and was similar to that of the synthetic insecticide treatment. Thus, the extracts could be a good alternative to the synthetic insecticides on organically managed farms as well as on farms of limited resource farmers in the tropics and subtropics.

Cadmium mobility in sewage sludge amended by four types of ameliorative materials (lime, limestone, bentonite and zeolite) incubated under aerobic and anaerobic conditions for eight months was studied in the experiment. The most statistically significant decrease of available Cd extracted by 0.01 mol/l CaCl₂ was recorded in sludge between second and fourth months of incubation. As most effective stabilizers were found limestone and bentonite added into the sludge incubated under aerobic and anaerobic conditions respectively. The presence of air reduced Cd mobility in individual sludges more than lack of air. Cadmium was separated by sequential extraction into five fractions as water soluble, exchangeable, bound with Fe and Mn oxides, organically bound, and residual fraction. Sequential analysis showed decrease of Cd in exchangeable and oxide fractions in sludge treated by lime and limestone at the end of aerobic incubation. Cadmium was found in water soluble and exchangeable fractions in small portion, even so its content in these fractions was higher than determined in slighter 0.01 mol/l CaCl₂ solution.

In the years 1999-2003 the effect of covering rows of early potatoes with non-woven fleece on the yield formation, dry matter content in tubers, temperature of soil and of air in ground layer was investigated. Covering of rows enhanced the market yield of tubers at early harvest 60 days after planting in average by 35.8% in comparison with the uncovered control. At harvest 67 days after planting the difference in advantage of the covered variant were 17.2% and 85 days after planting the difference in yield between variants was already non significant. The yield effect of the fleece was affected by year (higher effect in the years with cold spring) and by variety (Impala responded at 60 days after planting by yield increase under fleece 43.7%, Adora 27.9%). Higher dry matter content of tubers by 0.87% was found in covered plants 60 days after planting in comparison with control. Cover enhanced average air temperature in ground layer by 2.0°C, in soil in depth 100 mm by 1.8°C.

Three groups of Brown fattened young bulls were studied, comparing the effects of rearing method (suckled vs. bucket reared) and of slaughter weight (400 vs. 480 kg). Suckled animals had higher fatness scores (2.2 vs. 1.3), more dissectible fat (14.5 vs. 9.1%), and higher intramuscular fat content (7.8 vs. 4.6%DM), accompanied by better scores in sensory tenderness (5.2 vs. 3.8) than did the bucket-reared ones. Animals slaughtered at a heavier weight showed a higher dressing percentage (57.5 vs. 53.8%), conformation score (9.2 vs. 6.2), and fat content (fatness score, dissectible fat and intramuscular fat). The meat from animals in the heavier group had lower a* (12.4 vs. 14.2) and higher b* (10.8 vs. 12.9) indexes, as well as higher scores in most sensory traits than the lighter ones.

Two-year data from terminal study conducted to evaluate post-weaning growth and carcass traits of Texel, Suffolk and Columbia sired offspring were used to evaluate the effect of breed on cultural energy expenditure of lamb production. Each year whiteface ewes (n = 82) composed of primarily Polypay × Dorset ewes were exposed to Texel, Suffolk or Columbia rams for 35 days in the breeding season. The ewes were wintered outdoors on average-quality lucerne hay according to NRC (1985) requirements and were not provided any concentrate during late gestation or lactation. A total of 279 lambs were born with an average of 1.7 lambs per ewe and weaned lambs were used in the study. The lambs were weaned on average at 70 days of age and lambs from each sire breed were placed either in feedlot or on pasture. Texel and Suffolk sired lambs had higher weaning weight than Columbia sired lambs (P < 0.01). Lambs in the feedlot were fed shelled maize and pelleted protein supplement. Lambs on pasture grazed for 63 days and received 455 g concentrate daily and later they were placed in the feedlot. For the cultural energy analysis, pasture establishment and maintenance, feed in feedlot and on pasture, transportation, labour, machinery, electricity and other inputs were calculated and corresponding values for each input were obtained from literature. It was assumed for the analysis that 20 percent of ewes were culled and lambs sold after weaning were included in the analysis. Texel and Columbia breeds had a higher energy input per kg live weight than Suffolk breed (P < 0.04). There was no difference between breeds in terms of energy input per kg carcass (P > 0.4). Suffolk breed had a lower cultural energy ratio for the protein energy output than Columbia and Texel breed (P < 0.02). Energy output ratio defined as kjoule input/kjoule output was better for Suffolk breed and it was different from that of Columbia and Texel breed (P < 0.03).

The present study was designed to compare the efficiency of bovine embryo production for cryopreservation between oocytes collected from donors in the growth phase of follicular development (GPFD) and those recovered from donors in the undefined phase (UPFD). Cyclic cows, Czech Siemental or Holstein dairy breeds, 4-6 years of age, slaughtered at the local abbatoir were used. They were divided into two groups based on ovarian morphology: I. GPFD donors with ovaries corresponding to the growth phase of the first follicular wave (estrus cycle days 3-4; n = 52), and II. UPFD donors with ovaries in any other phase of follicular development (undefined estrus cycle days; n = 89). A total of 3 771 oocytes were collected and 1 134 embryos were prepared as two separate populations by standard protocol. In total 352 excellent or good quality embryos at the early, advanced or expanded blastocyst stage from both donor groups were pooled and used for cryotolerance assessment. They were frozen on day 7 (D7) or day 8 (D8) after fertilization by the standard procedure. After thawing, the embryos were cultured for 72 h to the hatching stage. The percentages of both D7 embryos and advanced blastocysts were significantly higher (P ≤ 0.01) for oocytes collected from GPFD donors than for oocytes collected from UPFD donors (33.7 vs 28.6% and 43.0 vs 29.5%, respectively). The percentages of excellent or good quality embryos obtained from both D7 embryos and fertilized oocytes were significantly higher (P ≤ 0.01) for oocytes collected from GPFD donors than for oocytes collected from UPFD donors (63.6 vs 49.4% and 21.4 vs 14.1%, respectively). The post-thaw survival rates were significantly higher (P ≤ 0.01) for D7 than D8 embryos (80.4 vs 66.3%). In relation to the developmental stage, the development and hatching rates were significantly higher (P ≤ 0.01) for D7 than D8 early blastocysts (75.0 vs 41.2% and 50.0 vs 5.9%, respectively) and for D7 than D8 advanced blastocysts, (73.7 vs 57.1 and 52.6 vs 28.6%, respectively). No differences were found between D7 and D8 expanded blastocysts after freezing-thawing. In conclusion, the collection of oocytes from donors in the growth phase positively influenced the in vitro production of bovine embryos for cryopreservation. The development of embryos produced with oocytes from GPFD donor group was accelerated and more excellent and good advanced blastocysts with greater cryotolerance were produced on day 7 after fertilization, as compared to embryos produced with oocytes from the UPFD donor group.

An experimental stand was established as a monoculture by planting Norway spruce on a clear-felled area in 1925. In 1958, a research thinning experiment was established there. Control plots and the study of their development without anthropic interventions are of interest in particular. The spruce monoculture nearly disintegrated and the stand-forming role was taken over by species which occurred there originally as admixed ones. The stand became sparser and it was associated with the spontaneous regeneration of broadleaves. Out of the eight control plots three plots were selected differing significantly in stocking and extent of natural regeneration. The development of regeneration was studied in detail on these plots. The undergrowth consisted of 24 woody species in a total number of 6,000 individuals per hectare and about two thirds of them belonged to trees. The results of the study show a possibility to convert a spruce monoculture to a broadleaved commercial forest using the spontaneous regeneration of trees.

The Delta Group with its daughter company Delta Pekárny, a.s., belongs to the most significant firms in the Czech food processing industry and it is number one baking company in the Czech market of fresh, long-shelf-life and frozen bakery products. The Delta Group associates eleven industrial bakeries in the Czech Republic and four in Slovakia, in addition to mills, Delta Frozen Products frozen-pastry plant, Delibake and Harry's Delta sweet long-shelf-life bakery products' plant, Vegilife company producing healthy food, Eureca Shops running Paneria, Fr. Odkolek fast-food outlets and Le Patio restaurants. In order to consolidate its status of a strong and successful Central-European company capable to meet all requirements of its customers, the company must perform a continuous analysis of external and internal environment.

The article deals with the usage of the information systems and expansion of the portals. In the part "results", there is elaborated a questionnaire applied on the agrarian sector. Today, the approach to the development of the information systems is oriented to the implementation of the portal solutions, which enables us a web access to the information and applications with an effective possibility of management and administration. Here, we are able to find typical user groups with quite specific information needs, who would find the specialized web portal very useful. This is because such kind of portal could offer them "everything at once and at one place", it means all of their needs would be satisfied immediately and users do not have to waste time with an information search at other places.

Fertilization with tannery materials positively influenced the soil pH and increased the content of alkaline cations in soil. After four years of investigations organic carbon content decreased most in the soil fertilized with untreated sludge, mineral salts and in the control soil. Irrespective of fertilization used and year of studies cadmium occurred mainly in most mobile fractions (mobile, exchangeable and bound to manganese oxides). Copper was mainly bound in fractions less available to plants. After four years of studies an increase in mobile copper forms was registered in all treatment soils. Lead in the soil was present mainly in the form bound to organic matter and amorphous iron oxides. Distribution of lead points to the small share of this metal in the mobile and exchangeable forms, both immediately after fertilization applied and after four years of studies. Chromium became fixed in fractions less available to plants, mainly bound to iron oxides and in residual fraction. On the other hand, an apparent effect of fertilization with materials of tannery origin on this element total forms content was registered.

Perennial ryegrass (Lolium perenne L.) is the most important grass species used in temperate grassland agriculture. Our objective was to obtain an overview of the genetic relationships between 20 individual genotypes of perennial ryegrass of diverse origins, using amplified fragment length polymorphism (AFLP), inter-simple sequence repeat (ISSR), random amplified polymorphic DNA (RAPD) and two sets of simple sequence repeat (SSR) markers. All 20 individuals were uniquely fingerprinted by all four marker systems and comparisons were made on the basis of 85 markers each. Mean genetic similarities were estimated at 0.31, 0.43, 0.23 and 0.15 for AFLPs, ISSRs, RAPDs and SSRs, respectively. Cophenetic values resulted in good (AFLP and SSR-B = 0.88) to moderately good fits (ISSR = 0.76, RAPD = 0.70, and SSR-A = 0.79). Comparing the four marker systems to each other, AFLP and SSR-A were correlated best (r = 0.57). All other comparisons revealed rather low correlation coefficients in the Mantel Z test. With twice as many markers cophenetic values increased to a very good fit for AFLPs (0.90) and SSRs (0.92).

In vitro study of the rumen fluid (RF) and hindgut content (HC) fermentation by microbiota taken from sheep grazing in an area atmospherically polluted from the non-ferrous metal industry was conducted and compared with controls from an uncontaminated area (UA). The experimental sheep were exposed to the prolonged intake of heavy metals by grazing in the contaminated area (CA) for one year. Soil and grass from that area and the rumen content of sheep were analyzed for heavy metal levels. Based on the levels of mercury (4.752 mg/kg), copper (232.9 mg/kg), cadmium (1.167 mg/kg), lead (92.509 mg/kg) and arsenic (74.59 mg/kg) the soil was categorized as profusely contaminated. Meadow hay (MH) from UA was used as a tested substrate of fermentation activity; it was incubated with buffered RF and HC inocula from CA and UA for 24 h. The gas volume in CA was significantly decreased by 50 and 36% in RF and HC, respectively. The methane production in CA was significantly decreased by 77 and 71% in RF and HC, respectively. The significantly decreased values of the fermentation parameters in CA in comparison with UA were accompanied by the reduced (P < 0.01) total concentration of rumen ciliate protozoa.

Live body measurements of weight, height, length, girth, stifle- and hip-width and a measure of muscularity (ratio of stifle to hip width) were monitored on 258 Yankasa sheep stratified into age categories of 1 to over 3 years determined mostly from records and partly by dentition. These animals are from purebred Yankasa sheep kept as a part of the open nucleus-breeding scheme of the National Animal Production Research Institute, Shika, Zaria, Nigeria. The effect of sex, type of birth and age group of lambs on live measurements and muscularity were analyzed by least-squares procedures. All variables examined, except sex, had significant (P < 0.001) effects on all body measurements. At birth, male and single-born lambs were significantly heavier than female and twin-born lambs. At early age, most factors significantly (P < 0.01) influenced the body weight, body dimensions and muscularity traits with single-born lambs being 31% heavier, 10% taller and 11% bigger in girth; more highly muscled than the twin-born lambs. This advantage of male over female born lambs (except in hip-width and girth) for growth and developmental traits was maintained reasonably well to the advanced ages. All phenotypic correlations between body measurements were positive and significant (P < 0.001). The highest correlation coefficient was found between chest girth and body weight. The polynomial equation using chest girth as an independent variable predicted body weight more accurately as compared to the linear equation.

To determine specific characteristics necessary for the computation of the C factor in RUSLE for timevariable crops, measurements were carried out in fields with selected agricultural crops grown by conventional practices. Sloping plots on an experimental area in Třebsin locality and farm fields were used to measure surface runoff and soil loss by erosion in conditions of natural and simulated rainfall. Basic characteristics to compute the C factor were determined in the particular growth phases of selected crops - sunflower, flax, poppy and rape. Effective root mass, canopy cover and fall height of rain drops were measured.

An extent of the damage of Austrian pine trees was evaluated in urban greenery in selected sites in Slovak Republic during the years 2004-2005. Fungi Sphaeropsis sapinea (Fr.: Fr.) Dyko & B. Sutton (syn. Diplodia pinea (Desm.) J. Kickx fil) and Pestalotia sp. were diagnosed on all observed trees. Symptoms of the disease were recorded. S. sapinea was isolated successfully from needles and from cone scales. The growth rate of hyphae of mycelium and the mean daily growth were evaluated on three types of cultivated media at different temperatures. The highest mean daily growth of mycelium was recorded on maltose agar at 25°C after 24 hours of cultivation (31.7 mm). Conidia of S. sapinea and Pestalotia sp. on water agar began to germinate after 3 and 2 hours, respectively. After 6 hours the mean germination rate of conidia of S. sapinea was 81.75% (from cone) and 89.3% (from needles); for Pestalotia it was 88.5%.

The aim of the study was to verify under experimental conditions the hypothesis that a reliable protection of piglets against Actinobacillus pleuropneumoniae (App) infection can be obtained by colostrum-derived antibodies and/or a low-dose infection from sows naturally infected with App. Twenty-eight piglets were allocated into four groups. Piglets of groups 1A and 1B were the progeny of App-seronegative sows, piglets of groups 2A and 2B originated from App-seropositive sows. At the age of 4 weeks, piglets in groups 1A and 2A were exposed to a low infection dose with the pathogenic strain of App serotype 9 (4 × 10⁴ CFU/ml). At the age of 8 weeks, all four groups of piglets were exposed to the App serotype 9 challenge (2.5 × 10⁷ CFU/ml). We compared the differences in clinical, radiological, pathological changes and cytological findings in blood and bronchoalveolar lavage samples between groups with different levels of antigen-specific immunity after challenge. Piglets that obtained colostrum-derived antibodies and experienced a low-dose App infection were best protected against App challenge. More apparent clinical and pathological changes were observed in groups protected with either only colostrum-derived antibodies or active immunity induced by a preceding low-dose infection. However, none of the types of protection prevented developing of the disease and characteristic changes in the lungs. Cell counts changes in blood and lavage gave evidence of only bacterial infection in progress; however, between-group differences were not marked. Antibodies (IgG, IgA) present in the respiratory tract at the time of challenge played a major role in protection against App infection.

3-amino-2-oxazolidinone (AOZ) is a tissue bound toxic metabolite derived from the nitrofuran antibiotic, furazolidone. AOZ is detected in the derivatised form of 3-{[(2-nitrophenyl) methylene] amino}-2-oxa-zolidinone (NP AOZ). 3-{[(3-carboxyphenyl)-methylene] amino-2-oxazolidinone (CP AOZ) was used as the immunising hapten for the production of monoclonal antibodies against NP AOZ. Monoclonal antibodies were produced using hybridomas from the fusion of murine myeloma cells and spleen cells isolated from BALB/c mice immunised with CP AOZ-ethylenediamine-human serum albumin (CP AOZ-ed-HSA). The antibody production in ascitic fluids from clones 3B8/2B9 and 2D11/A4 was monitored during a 16 month period. Repeated cultures of these hybridomas, followed by injection into mice and cloning did not change the assay parameters. Clone 2D11/A4 exhibited long term stability in antibody production throughout the experiment whereas clone 3B8/2B9 demonstrated variability in particular antibody yields whilst retaining assay sensitivity. Reasons for this production variability in clones are discussed. In an optimised direct ELISA format, the antibodies exhibited a 50% binding inhibition in the range of 0.52-1.15 ng/ml with NP AOZ (0.22 -0.50 ng/ml, respective AOZ equivalents) and showed high specificity towards this analyte. The sensitivity of monoclonal antibodies incorporated into the ELISA is compatible with the European Union MRLP and is currently in use for routine analysis.