Fulltext search in archive

A study was conducted to determine the relationship between abdominal fat and the intake of methionine deficient diet in broilers. In this study, 66 male broilers at the age of 35 days were used. They were divided into two groups (control, n = 13, and methionine deficient group, n = 53) and all birds were housed in individual pens. During the experiment, normal and deficient diet contained 0.55% and 0.25% methionine, respectively. Control group was fed normal diet for 19 days. Treatment group received methionine deficient diet for 4 days and normal diet for 15 days. Body weight and feed intake were recorded daily. High (HG) and low (LG) groups were theoretically created according to the rates of decreases in individual feed intake. Percent decrease in feed intake of HG and LG groups was 29.4 ± 2.0 and -1.3 ± 1.7, respectively. Abdominal fat in HG and LG groups amounted to 1.62 ± 0.1 and 1.73 ± 0.2%, respectively. The feed conversion ratio of HG and LG groups was 3.1 ± 0.1 and 3.4 ± 0.2, respectively. There was a negative correlation (-0.45 in HG and -0.43 in LG) between the percent decrease in feed intake and abdominal fat.

A geographic information system was used for the analysis of ecological conditions of distribution of natural foci of brucellosis in the European hare (Lepus europaeus) and their long-term persistence in the Czech Republic. The European hare is a reservoir host of Brucella suis biotype 2. A close correlation was found between the geographic distribution and numbers of natural foci of brucellosis in the Czech Republic in 1971 to 1985 and 1986 to 2000 (r = 0.65, n = 814, P = 0.01). Natural foci of brucellosis were persistent, but not stationary, over the period of 30 years. Natural foci of brucellosis were most abundant in habitats of beech forests and the mosaic of fields and forests (x_b = 3.19 and 2.95, respectively), geographic areas of 201-400 m of elevation above sea level (x_b = 2.53), 0.0-2.0°C of mean annual air temperature (x_b = 3.62), 1 401-1 800 mm of mean annual precipitation (x_b = 4.52), 1 601-1 800 h of mean annual sunshine duration (x_b = 2.64), and areas of the European hare population density of 51-100 individuals per 10 km² (x_b = 3.33). Natural foci of brucellosis seem to be independent of the population density of European hare.

The aim of this study was to characterise and compare Pasteurella multocida isolates originating from pigs (n = 43), calves (n = 31), rabbits (n = 27), and to a lesser extent from other hosts (n = 6). A total of 107 P. multocida isolates were obtained from various locations in the Czech Republic. They were analysed by capsular PCR typing and ribotyping, and tested for the production of dermonecrotoxin. Most frequently, serogroup A isolates (n = 74) were found, followed by serogroup D (n = 25) and serogroup F (n = 8) isolates. From a total of fifteen different ribotypes (1-15) generated by restriction endonuclease MspI, four ribotypes (1, 3, 4, and 7) were predominant. The prevalence of predominant ribotypes was different in isolates originating from different hosts. Ribotype 1 was characteristic for rabbit isolates, ribotype 3 was primarily found in pig isolates, and ribotype 7 dominated among calf isolates. Sixteen (mainly porcine) isolates produced dermonecrotoxin but significant correlation among ribotypes and dermonecrotoxin production was not observed.

In this report, a case of malignant fibrous histiocytoma involving skin, lungs, kidneys, pancreas and mediastinal lymph node was described. Microscopically, the tumor classified as storiform-pleomorphic type malignant fibrous histiocytoma.

In this paper we have evaluated the health condition of Prunus persica (L.) Batsch and Prunus armenia-ca L. for the occurrence of the parasitic microscopic fungus Cytospora cincta Sacc. Apricot trees in 5 localities with 10 sites and peach trees in 5 localities with 8 sites were evaluated. We identified symptoms of the disease in host plants, conditions for isolation and cultivation of the fungus and the growth rate of the mycelium hyphae on various substrates. The damage degree was evaluated in 330 trees in four localities while most trees were characterised by degree 1-3. We have derived conclusions for protective measures to prevent further spreading of the infection.

In 1986 (1987) research plots were established in a forest stands on the south-western slope of Šerlich Mt., Orlické hory Mts. (Kristina Colloredo-Mansfeld - Forest Administration Opočno), at the altitude of 950 to 970 m, to study deposition, chemistry of precipitation and soil water and development of soil chemistry. The plots were established on a clear-cut area, in a young stand and a mature stand of spruce, in a mature beech stand, and in an advanced growth of spruce and European mountain ash. The content of solutes in creek water was studied at the same time. Since 1993 the concentration of substances in precipitation water intercepted in the summit part of Šerlich Mt. has been measured. Research on water chemistry in the stands terminated in 1997. Soil analyses were done in 1986 (1987), 1993 and 1999. The load of acid air pollutants in these forest ecosystems was high in the eighties. After 1991 the deposition of H⁺, S/SO₄^2-, N/NO₃^- + NH₄⁺, Mn, Zn, Al decreased. Similarly, an increase in pH was observed in soil water, and the concentrations of SO₄^2-, and N, Al compounds decreased. But in 1993 the concentrations of SO₄^2- and Al increased again under the spruce stand for several months. The concentrations of NO₃^-, Mn, Zn and Al in the stream water also gradually decreased in the nineties. On the contrary, the average values of S-ions increased compared to those of 1987 to 1991. Strongly acid soil reaction developed in deeper layers until 1993. In the second half of the nineties the pH/H₂O value somewhat increased again, however the reserve of K, Mg, Ca available cations in the mineral soil constantly decreased. The saturation of sorption complex by basic cations in the lower layer of rhizosphere did not reach even 10% in 1999. The forest ecosystems of Šerlich Mt. were also loaded by a high fall-out of Pb, and increased fall-out of Cu. The lack of balance of N-compound transformations and consumption in the soil and increased leaching of N in the form of nitrates contribute to soil acidification on the investigated plots.

In the past ten years, meat and meat products consumption has changed dramatically. It has been caused by price and non-price factors. This article gives a brief recapitulation of the development of the consumption of meat and meat products and identifies the key factors which, in the past ten years, have had a major impact on this development. This article presents results of the secondary data analysis and the results of an inquiry into meat and meat products consumer behaviour carried out in the late 2004.

As a fermented product, tarhana is the dry form of yogurt-cereal mixture and represents an important part of the diets of many people in different countries including Turkey. In the present study, the effects of the addition of baker's yeast on the quality and functional properties of tarhana were investigated. Tarhana was produced under laboratory conditions (uncontrolled and controlled conditions) using two formulas. Some physicochemical, functional, and sensory properties of the samples were analysed. An increase was found in the acidity value of all samples during the fermentation period. The addition of baker's yeast affected the functional properties (water absorption capacity, foaming capacity, foaming stability, emulsifying activity) of the samples (P< 0.05). The tarhana samples produced by the addition of yeast and under controlled conditions had shorter fermentation times and better sensory properties. This research suggests that the addition of baker's yeast and the employment of controlled conditions can be recommended in the production of the commercial type of tarhana.

Two potato cultivars Kufri Bahar and Kufri Jyoti were stored in heaps and pits under ambient conditions of sub-tropical plains of northern India and their chipping quality was determined after 90 days of storage. During storage there was a significant reduction (33.84%) in the reducing sugar content of potatoes and improvement (31.63%) in chip colour. Sugar levels in stored potatoes were within the acceptable limit for processing and table purposes indicating that potatoes stored up to 90 days on the farm in heap and pits are suitable for these two purposes.

Amino acid content before and after heat treatment was assessed in grain of six selected amaranth varieties and four species: Amaranthus cruentus, A. hypochondriacus, A. caudatus and A. hybridus, cultivated in the Czech Republic. High content of Lys and Arg was detected in both heat treated and untreated grains, as well as satisfactory content of Cys and lower levels of Met, Val, Ile and Leu. The latter three amino acids appear as limiting. Chemical scores of essential amino acids and essential amino acid index (EAAI) were determined. EAAI value of 90.4% shows the favourable nutritional quality of amaranth protein, which is almost comparable with egg protein. Heat treatment by popping at 170 to 190°C for 30 s resulted in decreased EAAI to 85.4%. Of the essential amino acids under study, Val and Leu contents decreased significantly (P < 0.05). The relatively high content of essential amino acids in amaranth grain predetermines its use as a substitution of meat-and-bone meals.

This study deals with effects of pressing of ensiled sugar-beet pulp and of application of a chemical preservative on the quality of fermentation process. The experimental silages had a better sensory evaluation than the control ones. In silages treated chemically with a mixture of acids, statistically significantly (P < 0.01) higher dry matter content, lowest pH value, the value of lactic acid and the lowest content of all acids in dry matter were found after 180 days of storage from the beginning of the experiment. The statistically significantly (P < 0.01) highest lactic acid content (43.39 ± 1.25 g/kg DM) was determined in the control pressed silage. The highest LA/VFA ratio (1.40 ± 0.18) was calculated for non-pressed experimental silage (D - 3 l/t of KEM). As compared with untreated control the highest percentage (P < 0.01) of lactic acid and of all fermentation acids was found out in silage D treated with 3 l/t of KEM (58.18 ± 0.47 g/kg DM). Undesirable butyric and propionic acids were not found in chemically treated silage samples (C, D, E, F). However, the highest (P < 0.01) contents of butyric acid (26.37 ± 0.91 g/DM) and propionic acid (4.58 ± 0.78 g/DM) were measured in untreated non-pressed silage samples (B). The highest (P < 0.01) contents of acetic acid and ethanol were found in control silage samples. The quality of these silages was evaluated as very low.

The reed canary grass as a source of energy was tested in field experiments on small plots at three different sites in 1996-2003. The effects of soil and weather conditions, different times of harvest (July, November, March) and different doses of nitrogen fertilization (0, 30, 60 kg/ha) on yields of phytomass were investigated. The effects of the harvest time on the water content in harvested phytomass, loss of phytomass in different harvest period and the content of basic nutrients and heavy metals in plants were all specified. The influence of the year, site and N fertilization on yields of phytomass of the reed canary grass was highly significant. The reed canary grass responded positively to increasing doses of nitrogen by the increase of yields of phytomass. On the averages of years and sites, the N application dose of 30 kg/ha increased dry phytomass yields of the reed canary grass harvested in November by 14.6% (1.08 t/ha). The higher dosage of N 60 kg/ha increased yields of phytomass of the reed canary grass at all sites by 32.8% (2.08 t/ha) on average in contrast with variants without fertilization. By the dose of N 60 kg/ha, the dry above-ground phytomass harvested in autumn was 10.04 t/ha in Ruzyně, 8.27 t/ha in Lukavec and 6.94 t/hain Chomutov on average over the whole period. The later times of harvest resulted in a decrease of the average yield of phytomass (8.41 t/ha in July, 8.00 t/ha in November and 6.04 t/ha in March) and the average water content (64.3% - 45.2% - 21.5%); on the contrary, energy value of phytomass increased (16.93 GJ/t - 17.02 GJ/t - 17.19 GJ/t). The average content of ash in plants varied from 6.5% in Lukavec to 9.31% in Chomutov. The content of heavy metals in plants never exceeded the highest permissible values set in the Czech Republic for food and feed purposes.

New possibilities of oak mildew (Microsphaera alphitoides) control were tested and compared with present methods. The results of three-year experiments in 6 localities (Cikar, Budkov, Planá nad Lužnicí, Vědomice, Voznice, Zadní Bor) clearly showed that the sulphur-based fungicides registered for the control of oak mildew (Sulikol K, Sulka) had a relatively good and stable effectiveness, and that two other newly tested preparations (Systhane 12 EC, Amistar) were even more effective when the percentage of infested plants did not exceed 2% (Systhane 12 EC) or 5% (Amistar) in any experimental locality. Their registration should be extended in this way. The biopreparations with fungicidal or fungistatic effects such as Supresivit, Polyversum and Ibefungin, known and used in forestry, showed that it was not possible to use them for oak mildew control, similar results were received in tentative testing of another preparation (PFR). Testing of preparations Bion 50 WG and Neem Triact 90 EC gave interesting and promising results. Besides their sufficient effectiveness in the control of oak infestation by the mildew, our experiments also indicated their generally positive influence on the health of plants; this could compensate their economic disadvantage compared to classical fungicides.

Large areas were deforested as a consequence of the immission calamity in the Czech Republic in the last decades. As a part of restoration activities, preparatory species were utilized, both planted and sown, to cover forest soils, to prevent soil erosion and to regenerate forest microclimate, necessary for reintroduction of target, climax species. Birch (especially Betula pendula Roth.) was among the mostly common preparatory species. Presented paper documents the effects of birch in the case of its cultivation on an intact soil. In this case, birch was documented as a species suitable in a short-time perspective, improving soil characteristics and forming effective shelter against increased humus mineralization.

The article deals with characteristics of local communities and rural regions. Local communities are defined both according to the standards of population density and the number of inhabitants. In the article, there are treated especially the indicators of population development (balance of migration), economic activities of the inhabitants, unemployment rates, structures of the population according to the sector of national economy and the indicators of education. These indicators have been calculated on the basis of data of the Census 2001, municipal and regional statistics and the Department of Employment data concerning the unemployment rate.

Host range and growth of two Ditylenchus dipsaci (Stem and Bulb Nematode) populations on onion, garlic, leek, spinach and chicory were compared. Inoculation was conducted by placing a droplet of 1.5% CMC suspension containing nematodes between the first leaves. The life cycle of the parasite was completed in variants of the original host plants, i.e. salad chicory was infected with the chicory population, and garlic and onion with the garlic population. Survival of the nematodes on garlic and spinach inoculated with the chicory population, and on chicory inoculated with the garlic population was determined. Nematodes of the chicory population did not survive on onion and leek, nor did the garlic population survive on spinach and leek. Nematode infection did not affect the dry weight of aboveground parts of plants, although a reduction would probably occur if the experiments had lasted longer. Symptoms of the infections were apparent in chicory inoculated with the chicory population. Nematodes in the substrate in which the plants were grown were found only in those variants with plants in which the life cycle was completed.

The skin colour of 21 varieties was assessed on a molecular level. Four varieties had yellow skin colour with the genotype constitution a¹a¹, a¹a² or a²a². Seventeen varieties had dominant red colour. Homozygous A¹A¹ constitution was present in 7 varieties, and heterozygous constitution A¹a¹ or A¹a² was found in the rest of the assessed varieties. The S-alleles controlled the incompatibility system of the pistil. Their detection is possible by means of the PCR method on the basis of allele specific primers. Six S-alleles (S1, S2, S3, S5, S7 and S9) were studied in the same collection of 21 diploid Czech varieties. This paper brings new findings on S-allele characterization, because the Czech varieties have not yet been studied on a molecular level. Both types of S-allele were found in 12 varieties. Only one type of S-allele was described in 9 varieties. Simultaneously, the presence of the Vf gene was screened in the collection of 21 Czech apple varieties. Ten varieties with a field resistance against the scab had a heterozygous constitution of the Vf gene. All 11 susceptible varieties were recessive homozygous vfvf.

Fifty-one crossbreed young bulls, progenies of Charolais (CH), Czech Pied (CP), Simmental (SI) and Blonde d'Aquitaine (BA) beef cattle bred at the paternal position crossed by Czech Pied at the maternal position, were reared in a typical production system and slaughtered at an average age of 578 days and live weight of 656 kg. The animals were evaluated for fattening performance and carcass quality traits (live weight at slaughter, age at slaughter, total weight gain, carcass weight, dressing percentage, net daily gain) and meat quality characteristics (dry matter, proteins, fat, ash, pH₄₈, water holding capacity, remission, collagen, area of M. longissimus dorsi and cooking loss). Correlation coefficients were determined in order to discover which of the above-mentioned characteristics influenced textural properties measured by Warner-Bratzler (WB) shear device and compression test (TPA). It can be concluded from the overall assessment of the correlation coefficients that slaughter age (r = 0.68, P < 0.001), net daily gain (r = -0.54, P < 0.001), average lifetime daily gain (r = -0.50, P < 0.001) and pH₄₈ (r = -0.51, P < 0.001) had the major influence on the textural properties measured by WB shears. Meat texture expressed by TPA was mainly influenced by live weight at slaughter (r = 0.55, P < 0.001), carcass weight (r = 0.50, P < 0.001) and pH₄₈ (r = -0.54, P < 0.001). Significant differences (P < 0.001) were found out for the age at slaughter (CH × BA) and (CP × BA), slaughter weight (CP × SI) and (CP × BA) and carcass weight (CP × BA). At the same level of significance further differences were found out for pH₄₈ and water holding capacity (CP × SI), (CP × BA) and cooking loss (CH × CP). Highly significant differences (P < 0.01) in the textural properties (measured by WB shears) were determined between the following breeds: (CH × BA) and (CP × BA). At the level of significance P < 0.05, the highest differences were identified between (CH × SI) and (CP × SI). TPA test showed statistically significant differences between (CH × CP), (CP × SI) breeds at the level P < 0.05.

Enterococci (58) from faeces of rabbits of various age (from 2 months to 3 years) and 5 different rabbit farms were isolated and tested for survival in the presence of oxgall, lactic acid production, urease activity, resistance to low pH as well as their binding ability was tested. Fifty percent of enterococcal isolates were identified as Enterococcus faecium, 19% as E. faecalis. All strains showed good survival in the presence of 5% oxgall. The urease activity of isolates was in the range from 0.013 to 17.13 nkat/ml, only E. faecalis EE229 strain did not produce any urease. The survival of strains was tested at pH 3.0 and the percentage of their survival ranged between 62.0% and 90.0%. E. faecium EF1819 strain was found to show the best survival ability at low pH. Particle agglutination assay values of selected enterococci expressed only negative (0) or weakly positive (1) binding of heparin, bovine fibrinogen, porcine fibronectin and lactoferrin. Based on the results, most of the selected enterococci could be promising probiotic feed additives.

Ninety-three rectal swabs of lambs and young goats from two extensively and two intensively managed herds in Jordanwere taken and examined for Shiga toxin-producing Escherichia coli (STEC). The bacteriological examination included the preenrichment of rectal swabs in EC broth with novobiocin, and a subsequent parallel isolation on enterohemolysin agar and immunomagnetic separation with cultivation on CT-SMAC. The STEC O157:H7 strains were demonstrated in 8 of 32 diarrheic lambs 1- to 3-weeks old in one sheep herd with intensive milk production. In the remaining three herds, serogroups O128, O78, O15 and serotype O128:K85 of STEC strains were the most frequent findings. The presence of stx2, ehlyA and eaeA genes in all STEC O157:H7 isolates was confirmed by PCR. In two untypable STEC isolates, stx2 and ehlyA genes were detected. In other STEC non-O157 isolates, only stx1 a ehlyA genes were found. All STEC O157:H7 isolates were resistant against sulphonamides and chloramphenicol, five were also resistant against ampicillin and streptomycin, one against co-trimoxazole. One isolate was resistant against ampicillin, ampicillin-sulbactam, cephalosporins (cefazolin, cefuroxime), monobactams (aztreonam), sulphonamides, co-trimoxazole, aminoglycosides, tetracycline and chloramphenicol. Compared the resistant STEC O157:H7 isolates, the multiresistant isolate had a different RAPD pattern. Of 36 STEC non-O157 isolates, one isolate was resistant against sulphonamides and co-trimoxazole, and another one against ampicillin, streptomycin, sulphonamides and co-trimoxazole. STEC isolates resistant against antimicrobial agents were demonstrated only in herds with intensive management.

A total of 245 isolates of Actinobacillus pleuropneumoniae included in this study were isolated from lung tissues of pigs which died of porcine pleuropneumonia. The isolates were obtained from 52 swine herds in the Czech Republic over the period 2003-2004. All the serotypes were serotyped by the coagglutination test. All isolates with cross-reactivity between serotypes 9 and 11 or 1, 9, and 11 in the coagglutination test were further serotyped by the quantitative coagglutination test. The results of serotyping showed that serotype 9 was dominant (46.5%) followed by serotypes 2 (18.5%), and 11 (14.2%). Two-way cross-reaction between serotypes 9 and 11 was found for 7.5% of the isolates. The serotypes 4, 5, 7, and 12 were found infrequently (2.4%). The isolates that could not be serotyped (11%) were classified by PCR typing system based on the apx and omlA genes into the serotype groups 1, 9, 11 (7.5%); 2, 8 (2.3%), and 7, 13 (1.1%).

In 1997 the Research Institute for Fruitgrowing and Ornamentals set up a comparative rootstock trial to study foreign-bred dwarf cherry rootstocks in the Hungarian climate. Based upon their effects on trunk and canopy growth, rootstocks can be classified into 3 groups: very vigorous (Cerasus mahaleb L. Cema, Cerasus avium L. C. 2493, Weiroot 13), medium vigorous (Weiroot 158, Weiroot 154, P-HL-A) and dwarfing rootstocks (Weiroot 72, Weiroot 53, GiSelA 5). Differences between the blooming and ripening times of rootstock/scion combinations were also observed. Linda produced the highest cumulative yield followed by Katalin, Germersdorfi 3 and Piramis. The largest fruit diameter was measured in Germersdorfi 3 among the sweet cherry cultivars; the highest ratio of fruits larger than 26 mm was found on Weiroot 72, and the lowest on GiSelA 5. The largest fruit diameter of the sour cherry Piramis was observed in trees on Cerasus avium C. 2493.

This material describes parameterization of allometric functions applicable to biomass estimation of European beech trees. It is based on field data from destructive measurements of 20 full-grown trees with diameter at breast height (dbh) from 5.7 to 62.1 cm. The parameterization was performed for total tree aboveground biomass (AB; besides stump), stem and branch biomass, respectively. The allometric functions contained two or three parameters and used dbh either as a single independent variable or in combination with tree height (H). These functions explained 97 to 99% of the variability in the measured AB. The most successful equation was that using both dbh and H as independent variables in combination with three fitted parameters. H, as the second independent variable, had rather a small effect on improving the estimation: in the case of AB, H as independent variable improved prediction accuracy by 1-2% whereas in the case of branch biomass by about 5%. The parameterized biomass equations are applicable to tree specimens of European beech grown in typically managed forests.

Expansion and invasion of plants indicate successful colonization and competitive abilities of species. There are fewer invasive and expansive woody plants than herbs. Main expansive (native species) trees and shrubs are Acer platanoides, Acer pseudoplatanus, Clematis vitalba, Crataegus sp. div., Fraxinus excelsior, Prunus spinosa, Rubus sp. div., Sambucus nigra. Main invasive (alien species) are Acer negundo, Ailanthus altissima, Amorpha fruticosa, Cytisus scoparius, Fraxinus pennsylvanica, Lycium barbarum, Mahonia aquifolium, Physocarpus opulifolius, Pinus strobus, Populus × canadensis, Prunus serotina, Quercus rubra, Rhus typhina, Robinia pseudoacacia, Symphoricarpos albus, Syringa vulgaris. Dominant characteristics of expansive and invasive species are dispersibility of seeds and capacity of vegetative propagation.

Czech agricultural sector undertook many great changes in the last 12 years. These changes have resulted in the creation of business structure, which, however, is still not finished due to external (market) and internal (enterprise) conditions. The main goal within these changes was to create functional efficient and competitive agricultural sector, which is to survive in ever changing global world, in particular with respect to the intention to join the unified Europe. One of the questions, which is currently discussed very often, is to what extent the current business agricultural structure is efficient in input allocation, eventually which structural changes have to be undertaken to create such effective sector. The main objective of this contribution is therefore to present findings, which were obtained within the research project processing.

The principal importance and global dimension of sustainable agriculture in frame of a strategy of civilization development is beyond discussion. The actual character of the topic of looking for ways to sustainable development is confirmed by the extensive worldwide program "Millennium Ecosystem Assessment" the purpose of which is to map and subsequently monitor the health of the planet Earth. The contribution is focused on various aspects of the non-substitutable role of agriculture regarding sustainable development on the level of developing and developed countries and on the regional and global level.

The paper is focused on the analysis of the wine demand and chosen factors which influence the wine demand in the Czech Republic, in Slovakia, in Austria, and in Germany. In the Czech Republic, the wine consumption per inhabitant went up slightly in 1994-2003, the wine demand has a rising trend. The wine demand has the rising trend in Germany as well. In Slovakia, the year wine consumption per inhabitant decreased by 14.9% from 1994 to 2003; in Austria by 7.7%. There is a downward trend of development in these countries. The influence of the analyzed factors on the development of the wine demand is different in the particular countries. The dependence is possible to follow at the total level of incomes in comparison with the consumer's price of wine.

The response of 25 registered winter wheat varieties to autumnal infection with Wheat dwarf virus (WDV) was studied in small plot trials in two years. The materials were infected by vectors, leafhopper Psammotettix alienus Dahlbom, 1851 from three-leaf stage to tillering. The symptoms expression was monitored in spring and plant height, weight of above ground biomass and grain yield were observed in summer. All tested varieties were evaluated as susceptible and divided into three groups: varieties Banquet and Svitava with 87.3-93.1% grain yield reduction as moderately susceptible, varieties Clever, Drifter, Niagara and Rialto with 95.6-97.68% grain yield reduction as susceptible and varieties Apache, Batis, Bill, Complet, Contra, Corsaire, Ludwig, Mladka, Nela, Record, Rheia, Semper, Sepstra, Solara, Sulamit, Tower, Trend, Vlasta and Winsdor with 99.7-100% grain yield reduction as very susceptible. Statistically significant differences were observed between moderately susceptible and susceptible varieties as well as very susceptible ones in absorbency values by means of DAS-ELISA.

There is a constant increase in demand for large numbers of high-quality oocytes of domestic mammals for various reproductive biotechnologies. Prolonged in vitro culture represents one of the many possible ways of meeting this demand. However, oocytes further cultured in vitro after reaching the stage of metaphase II undergo the complex process called "ageing", which decreases the quality of oocytes. The aim of the present study was to improve the culture conditions for in vitro matured porcine oocytes by supplement of the epidermal growth factor (EGF) or the insulin-like growth factor 1 (IGF-1) in order to reduce the adverse effects of ageing. Supplement of either EGF or IGF-1 had no significant effect on the ageing of porcine oocytes. Significant effects were demonstrated when the oocytes were cultured with both EGF and IGF-1. A combination of 10 µg EGF/ml with 25 ng IGF-1/ml was the most effective. Oocytes aged under these conditions retained very good developmental competence. We observed development to the morula (21%) or blastocyst (25%) stage in oocytes aged for 1 day with EGF and IGF-1. Porcine oocytes matured in vitro are more resistant to the ageing when cultured in the presence of both EGF and IGF-1 and these conditions retain an elevated developmental competence for a certain time.