Fulltext search in archive



« advanced mode »

 previous    ...   75   76   77   78   79  80   81   82   83   84   ...    next 

Results 2341 to 2370 of 5716:

Trust evolution, institutional constraints, and land trusteeship decisions among Chinese farmersOriginal Paper

Qi Li, Menghui Gao

Agric. Econ. - Czech, 2023, 69(12):485-497 | DOI: 10.17221/232/2023-AGRICECON


Land trusteeship involves farmers entrusting the farming and managing of their land to trustees, who manage the land on their behalf in exchange for a commission fee. Land trusteeship has been an important approach to bridging the gap between smallholder farmers and modern agriculture in China. Because of the information asymmetry in land trusteeship, farmers have higher uncertainty and perceived risk, so social trust and institutional constraints are particularly important in promoting farmers’ participation in trusteeship. The objective of this study was to examine the impact of trust evolution and institutional constraints on smallholder farmers’ decision-making in green prevention and pest control trusteeship. Our research was conducted in Shandong, China, utilising factor analysis and binary regression. The results revealed that trusteeship decision-making combines trust governance and institutional governance, with significant roles played by institutional trust, institutional supervision, institutional regulation, and interpersonal trust. As part-time farming became more prevalent, the importance of institutional trust and institutional supervision increased, indicating a shift in trusteeship governance from social relations to institutional contracts and the maturation of land trusteeship models. In addition, we also tested the interaction effect of social trust and institutional constraints and the heterogeneity effect of different trusteeship contracts. To improve the land trust system, we must enhance farmers’ institutional trust and leverage the active role of intermediary supervision organisations such as village collectives.

Impact of project information disclosure on backers‘ investment intensity in reward-based crowdfunding: Evidence from agri-food crowdfunding in ChinaOriginal Paper

Junjuan Du

Agric. Econ. - Czech, 2023, 69(11):427-435 | DOI: 10.17221/249/2023-AGRICECON

How to encourage backers to increase investment and obtain more funds is an important issue for both initiators and platforms in reward-based crowdfunding. Based on the trust theory and the elaboration likelihood model (ELM), this study explores the impact of project information disclosure on the investment intensity of backers in agri-food crowdfunding. The results show that the initiator type, trademark registration, number of certificates, number of reward types, number of project updates, and number of comments had significant positive effects on backers’ investment intensity. Meanwhile, the investment threshold and lottery had a significantly negative impact on backers’ investment intensity. The number of backers played a mediating role in the relationship between independent variables and backers’ investment intensity. Based on the research conclusions, practical implications were proposed for initiators, crowdfunding platforms, and regulators.


Working capital management in the food and beverage industry: Evidence from listed European companiesOriginal Paper

Hakan Özkaya, ªebnem Yaºar

Agric. Econ. - Czech, 2023, 69(2):78-88 | DOI: 10.17221/383/2022-AGRICECON


Optimizing current assets and their financing resources is of great importance for firms to sustain their existence with the highest level of profitability. However, empirical evidence from the food and beverage industry on the effects of working capital management (WCM) on profitability is scarce and mixed. This study aims to understand how various components of WCM affect the profitability of listed European food and beverage (F&B) companies. For this purpose, static panel data methodology was used to test the relationship between profitability and WCM measured by the cash conversion cycle and its components. The results were checked for robustness by using dynamic panel data methodology. Our results indicate a negative relationship between profitability and the cash conversion cycle. Unlike previous studies that have analysed a single country, this study provides evidence based on analyses of the largest possible sample of listed European F&B companies.

Influence of the surface/volume ratio on the rheological properties of starch dispersionsOriginal Paper

Gerardo Lopez-Echevarria, Jorge Adalberto Huerta-Ruelas, Gonzalo Velazquez, Martin Jesús Nieto-Perez, Guadalupe Mendez-Montealvo

Czech J. Food Sci., 2023, 41(1):54-63 | DOI: 10.17221/155/2022-CJFS


This study aims to evaluate the influence of the surface/volume granule ratio of amaranth, corn, and potato starches on the rheological properties of pastes and gels obtained at 5 and 10% solids concentration through granulometry, scanning electron microscopy, rotational, and dynamic rheological measurements. The granule size distribution and the surface/volume ratio drove the rheological behaviour as a function of temperature and concentration. At a concentration of 10%, the consistency index of corn starch (CS) paste was 147.25 Pa·sn (n – flow behavior index), a higher value compared to pastes from potato starch (PS), 86.54 Pa·sn, and amaranth starch (AS), 44.48 Pa·sn. The lowest values of the loss angle tangent (Tan δ) in CS (0.052 and 0.035) at both solids concentrations suggested a better gel conformation. Noticeable changes in consistency index and storage modulus were observed in CS. A theoretical analysis of the surface/volume ratio change showed that CS reached a 2.2 value, much lower than the 4.5 and 5.8 values for PS and AS, respectively. These findings provide additional criteria for the food industry when choosing starches with suitable rheological behaviour as a function of surface/volume granule ratio and solids concentration.

Incidence of thermophilic, grass and rare arable weeds in cereal fields in the Czech and Slovak RepublicOriginal Paper

Michaela Koláøová, Ludìk Ty¹er, Theresa A. Reinhardt Piskáèková, Jana Májeková

Plant Soil Environ., 2023, 69(3):131-140 | DOI: 10.17221/439/2022-PSE

Our objectives were to characterise arable weeds of the Czech and Slovak Republic in cereals, especially considering important groups of species: thermophilic, weedy grasses, and rare and endangered species. The three-year phytocoenological survey was conducted from 2006 to 2008 in five climatic regions and eight different soil types. 379 relevés were recorded, and 281 weed species were found. The effects of both the climatic region and soil type were found to be statistically significant. Species richness increased with altitude. Several species were distinctly associated with soil type, from fertile chernozems to less fertile cambisols, while fluvisols were strongly associated with e.g. Calystegia sepium (L.) R. Br. The incidence of species outside their expected regions generally fit two categories: the most pervasive weeds found almost in all climate regions, such as Echinochloa crus-galli (L.) P. Beauv., or rare weeds in higher altitudes than expected, such as Lolium temulentum L. Rare and endangered species were more likely to be found in a colder climate and poorer soils, and this is linked to less intensive management; however, not all endangered arable species can tolerate such conditions. Even though this data is not recently collected, this is still valuable information on the distribution of weedy species, especially concerning the current interest in maintaining biodiversity.

Long-term exposure to polycyclic musk tonalide – A potential threat to juvenile zebrafish (Danio rerio)?Original Paper

J Cahova, J Blahova, L Plhalova, P Marsalek, V Doubkova, M Hostovsky, L Divisova, J Mares, C Faggio, Z Svobodova

Vet Med - Czech, 2023, 68(5):218-224 | DOI: 10.17221/40/2023-VETMED


Polycyclic musk compounds are commonly used in personal care products to replace expensive natural fragrances. Due to their huge consumption, they have become a part of the aquatic environment. In the present study, a two-month exposure effect of tonalide on juvenile zebrafish (Danio rerio) was investigated. We determined the vitellogenin concentration to define the potential endocrine-disrupting effect of tonalide and also analysed selected indices to evaluate the induction of oxidative stress. The environmentally relevant concentration of tonalide (i.e., 500 ng/l) caused a significant decrease in the catalase activity (< 0.05) and a significant increase (< 0.05) in the lipid peroxidation. An increasing lipid peroxidation was also recorded for the highest concentration group tested (i.e., 50 000 ng/l). On the other hand, no significant changes were recorded in vitellogenin in all the exposed groups. Thus, based on these results, we have not demonstrated the endocrine-disrupting activity of tonalide in zebrafish. The results of the oxidative stress indices showed a significant impairment of the antioxidant defence after the two-month tonalide exposure, which could indicate part of the adaptive response to the tonalide toxicity.

Effect of onion waste powder on the rheological characteristics, sensory attributes, and antioxidant properties of mayonnaiseOriginal Paper

Tsvetko Prokopov, Kremena Nikovska, Milena Nikolova, Pavel Merdzhanov, Mina Dzhivoderova-Zarcheva

Czech J. Food Sci., 2023, 41(3):182-188 | DOI: 10.17221/19/2023-CJFS


The recovery and utilization of onion processing waste would contribute to the solution of environmental problems. This research presents the way of successful supplementation of onion processing waste in mayonnaise. Different levels (0, 1, 2, and 3%) of onion waste powder (OWP) were used as an additive to mayonnaise, based on sunflower oil. The final mayonnaise formulations were evaluated for sensory properties, rheological behaviour, oxidative stability, total phenolic content, total flavonoids, and antioxidant activity. The results indicated that OWP could be used as a potential health-promoting functional ingredient in amounts of 2% to produce mayonnaise enriched with total phenolic compounds and flavonoids, having high antioxidant activity, acceptable quality, and overall consumer preference.

Predispositions and challenges of agriculture from areas particularly facing natural or other specific constraints in Poland in the context of providing environmental public goods under EU policyOriginal Paper

Marek Zieliñski, Jan Jadczyszyn, Jolanta Sobierajewska

Agric. Econ. - Czech, 2023, 69(8):309-320 | DOI: 10.17221/184/2023-AGRICECON


The study’s main objective is to determine the predisposition and challenges of agriculture to provide environmental public goods to society in areas particularly facing natural or other specific constraints (ANCs) established within their current delimitation in Poland. Its organisational features, economic situation, and the degree of interest in measures specifically serving the protection of the natural environment under the Common Agriculture Policy (CAP) EU were indicated. Statistically significant factors determined farmers’ willingness to participate in these measures. It turned out that farms from ANCs communes with particularly difficult conditions significantly contribute to the total production potential of agriculture in Poland. However, compared to farms with better natural conditions, they are characterised by a lower income per 1 ha of utilised agriculture area (UAA) and a higher share of subsidies, including those for participation in environmental measures, which were implemented to a greater extent. Based on the logistic regression model, it was found that in ANCs communes with particularly difficult conditions, the most important factor of farmers’ greater willingness to implement environmental measures was their higher level of education. On the other hand, this inclination was negatively affected by the higher income adjusted for operating subsidies per 1 ha of UAA.

Tetragenococcus halophilus, Staphylococcus xylosus and Staphylococcus saprophyticus for sardine fermentationOriginal Paper

Zhijia Fang, Wenjuan Zhu, Ying Liu, Xinran Wang, Yaling Wang, Yanyan Wu

Czech J. Food Sci., 2023, 41(4):271-278 | DOI: 10.17221/246/2021-CJFS


To improve the quality and enrich the flavour of fermented sardine, Tetragenococcus halophilus, Staphylococcus xylosus, and Staphylococcus saprophyticus were used as a mixed starter for sardine fermentation. And their proportions were optimised using response surface methodology (RSM). The highest sensory score was obtained when the proportions of T. halophilus, S. xylosus, and S. saprophyticus were 1:1:1. The optimised fermented sardine had the lowest levels of histamine content (0.0190 μg·g–1), total volatile basic nitrogen (TVBN, 208 μg·g–1), and was richer in volatile compounds (308). The results may provide important evidence that T. halophilus, S. xylosus, and S. saprophyticus may be satisfactorily used as a mixed starter to improve the quality and flavour of fermented sardines.

Changes in the behaviour of Czech Fleckvieh dairy cows during the day under optimal ambient temperature conditions in the barnOriginal Paper

Milan Veèeøa, Stanislav Navrátil, Tomá¹ Kopec, Daniel Falta, Gustav Chládek, Francois Stefanus Lategan

Czech J. Anim. Sci., 2023, 68(9):365-371 | DOI: 10.17221/23/2023-CJAS

In the experimental section of the barn (which made up 25% of the barn), 103 cubicles in free stall barn were selected in three rows, housing 98 dairy cows of Czech Fleckvieh cattle. Monitoring was done for one calendar year, once a week. From this period, 16 days with temperatures from 0.5–15.0 °C were selected for quantification. Observations were continuously recorded at 10:00 am (one hour after the coming of the last cow from the milking parlour), at hourly intervals until 7:00 pm. Ten observations were carried out every day of the monitoring period. In total, 15 680 individual observations were recorded. The microclimatic parameters (temperature, relative humidity) were monitored within the barns continuously at 15-minute intervals using three data logger sensors. Changes in the proportion of lying to standing dairy cows were observed during the day. A steady trend of a reduced ratio of lying dairy cows during the day (from 70% to 40%) in favour of standing dairy cows was observed. The optimal value of the cow comfort index – CCI (85%) was not reached in any monitored part of the day. The number of dairy cows lying on their left sides increased from 50.4% to 56%, especially after feeding (at 4:00 pm). Differences were found in the proportion of lying and standing cows (< 0.05) at an optimal microclimate during the day. A significant preference for the left side when lying down was also found.

Evaluation of five rootstocks on the growth, gas exchanges and chlorophyll fluorescence of Juglans regia L. cv. ‘Xiangling’Original Paper

Bing Hua Liu, Liang Cheng, Ji Xia Zhang, Lian Jia Yui, Hai Lin Ma, Fangchun Liu

Hort. Sci. (Prague), 2023, 50(3):208-218 | DOI: 10.17221/152/2022-HORTSCI

Our study comparative analyzed the morphological and physiological performance of Juglans regia L. cv. ‘Xiangling’ (JRX) grafted onto five rootstock species originated from China. A wide range of coefficient of variation (CV), 1.155–39.848%, was detected for fourteen indexes among the studied seedlings. CV of plant height, total dry biomass, total leaf area, root/shoot ratio, chlorophyll index, and stomatal conductance was higher than 15.00%, suggesting higher variation. Principal component analysis, hierarchical cluster analysis and subordinate function analysis were used to screen engrafted seedlings for their quality. All three methods produced the same result that seedling quality of ‘Xiangling’ engrafted with the five rootstock species from high to low were – Juglans regia L. cv. ‘Jizhaomian’ (JRJ), JRX, Juglans regia L. cv. ‘Lvxiang’ (JRL), Juglans mandshurica, Maxim., and Juglans hopeiensis Hu.. The evaluation results were highly consistent with the actual growth performance of the engrafted seedlings, it verified the reliability of our results and the evaluation methods. The results demonstrated that JRJ, JRX, and JRL are potential rootstock candidates in the studied walnut planting regions. It would provide important implication for the selection of proper rootstock species for a certain particular walnut variety.

Water activity of Czech dry-cured meat products: Influence of sampling point and sample preparation methodOriginal Paper

Filip Beòo*, Jan Kostlán, Jan Pivoòka, Václav Pohùnek, Rudolf ©evèík

Czech J. Food Sci., 2023, 41(5):340-347 | DOI: 10.17221/99/2023-CJFS


Water activity (aw) is a key factor influencing dry-cured meat products' safety. However, the standards for determining aw do not specify how the laboratory sample for self-analysis should be prepared and adjusted for determination in this type of food. This work aimed to verify whether the place of sampling and method of sample preparation of dry-cured meat products can influence the measured value of aw. For this purpose, samples of dry-cured heat-treated and fermented meat products were purchased from the local market. Samples before analysis were taken from the edges and centre of the meat products, and preparation consisted of: i) homogenisation; ii) dicing (4 × 4 × 4 mm); iii) slicing. The results of this work indicate that aw is significantly affected by both the part of the product from which the sample is taken and the method of preparation of the sample itself (P < 0.05). The highest measured values of aw were determined in samples prepared by slicing, and the lowest values were determined in homogenised samples. The place of sampling significantly affects the aw, especially for dry-cured heat-treated products.

The potential of glyphosate-alternatives like electrophysical weeding in the stale seedbed method for Alopecurus myosuroides (Huds.) controlOriginal Paper

Benjamin Klauk, Jan Petersen

Plant Soil Environ., 2023, 69(11):522-531 | DOI: 10.17221/386/2023-PSE


Changing political demands requires the search for alternatives to glyphosate, which has often been used in the stale seedbed method. In three field trials between 2020 and 2023, three electrophysical treatments (XPower System, Zasso®) differing in speed, three mechanical treatments (disc harrow, rotary harrow, cultivator) and three chemical treatments (glyphosate, maleic hydrazide, pelargonic acid + maleic hydrazide) were evaluated concerning the efficacy and economic performance in stale seedbed method in Alopecurus myosuroides control. Process costs for each treatment were calculated. Furthermore, the maximum investment costs for the XPower system were calculated to be on the same level as the other treatments. In all treatments, the density of A. myosuroides in autumn was significantly lower than in the control. In general, the fewest plants and heads were found in the chemical treatments. Despite the lower plant density, the electrophysical method did not show a significant difference in the number of heads compared to the untreated control, especially at higher speeds. Calculated process costs ranged between
40 €/ha (glyphosate) and 430 €/ha (pelargonic acid + maleic hydrazide). To be economically comparable with the other treatments, the investment of the XPower should be at maximum between – 219 000 € (glyphosate) and 300 000 € (pelargonic acid + maleic acid), depending on the driving speed. In a holistic view, electrophysical control, as well as pelargonic acid and maleic hydrazide as glyphosate alternatives in the stale seedbed method, are not suitable. A stale seedbed with mechanical control of A. myosuroides is recommended.

Influence of elevated ambient temperature upon some physiological measurements of New Zealand White rabbits

L. Ondruska, J. Rafay, A.B. Okab, M.A. Ayoub, A.A. Al-Haidary, E.M. Samara, V. Parkanyi, L. Chrastinova, R. Jurcik, P. Massanyi, N. Lukac, P. Supuka

Vet Med - Czech, 2011, 56(4):180-186 | DOI: 10.17221/3150-VETMED

This study was conducted to investigate the effect of heat stress (i.e., elevated ambient temperature - Ta; 36 °C ± 3 °C) on growth performance, mortality rate, and on some haematological and biochemical parameters in different categories of gender and age of New Zealand White (NZW) rabbits. Animals were divided into two main groups (control and treatment), in each group there were 56 rabbits: adult females (n = 20), adult males (n = 4), growing females (n = 16), and growing males (n = 16). Results revealed that total and daily feed intake, feed conversion ratio, and total and daily gain in body weight for growing NZW rabbits were affected negatively by elevated Ta. Decreases in feed intake led to less protein biosyntheses and less fat deposition, which led to lower body weight gain. These observations were made in growing and adult rabbits of both genders. Analysis showed that red blood cell (RBC) counts showed alterations. Packed cell volume (PCV) (in adult females and males), white blood cell (WBC) counts (in growing females), lymphocytes (in growing males), monocytes (in growing females and adult males), basophils (in growing females and growing and adult males) were significantly (P < 0.05) decreased, and total proteins (TP) (in adult females), glucose (Glu) (in adult females), and calcium (Ca2+) (in growing males and females) were significantly (P < 0.01) lower in the experimental group. Furthermore, elevated Ta increased the mortality rate (MR) in both age groups. The mortality rate was 30.36% for growing and adult rabbits of the experimental group, compared with 7.14% for the control group, and was 25% for adult compared with 34.38% for growing experimental rabbits. Exposure of NZW rabbits of both ages and genders to elevated ambient temperature (36°C ± 3 °C), negatively affected their internal homeostasis which was reflected in their growth rate and various physiological signs.

Antioxidant activity of enzymatic system of two different wheat (Triticum aestivum L.) cultivars growing under salt stress

W.M. Bhutta

Plant Soil Environ., 2011, 57(3):101-107 | DOI: 10.17221/95/2010-PSE

Soil salinity and semi-arid and arid climate of Pakistan is a major constraint in agriculture and predominantly in foodstuff production. It limits crop yield and use of land previously uncultivated. Wheat is moderately salt tolerant. A great variation was observed between and within the cultivars (genotypes: S-24 salt tolerant and DN-27 salt sensitive) in relationship to the choice of salinity level (control and treatments: in increment of 25 mol/m3 NaCl/day to a final level of 80 and 160 mol/m3 NaCl into the nutrient solution) that will be used for screening purpose. Relative water content (RWC), membrane stability index and the activities of some antioxidant enzymes were determined after 20 and 40 days of salt stress exposure. As a result of activity enzymes, superoxide dismutase (SOD), peroxidase (POD) and catalase increased in S-24 with the increase of salt stress, while in DN-27 all the enzymes showed constant activity at all the stress levels. Meanwhile, relative water content and membrane stability index decrease the value as well as they increases the stress levels. It can be concluded that all three antioxidant enzymes were limiting factors for these genotypes and these reasons also led to the salt sensitivity in DN-27. Different selection methods should be applied to improve different traits in different conditions in wheat.

Evaluation of squared timber and log products in the Hyrcanian Forests of Iran

S.M. Hosseini, B. Majnounian, A. Skoupý

J. For. Sci., 2011, 57(2):64-69 | DOI: 10.17221/90/2009-JFS

The forests located in the northern areas of Iran are known as Hyrcanian Forests and are distributed across three provinces, namely Gilan, Maznadarn and Golestan. These provinces are situated in the north of Iran near the Caspian Sea. Timber products in the said forests during the last two decades were markedly different so that the total timber harvested in the first decade was 1.6 million m3 on average, however, in the second decade it nearly amounted to 1 million m3. Two major timber products of Iran are studied and compared in this research, namely logs and squared timber. Squared timber products averaged 10.7% during the first decade, but they fell to 7.3% over the second decade. Apropos of log products, they reached 20.9% and 29.2% over the first and the second decade, respectively. Analyses of the data indicate the following converse linear equation between squared timber products and log products during the 20 years of study: Y =-0.359X + 18.065 (Y = log products, X = squared timber, R2 = 0.768).Accordingly, any increase in log products at a time caused the squared timber products to decrease at the same time.

The effects of flour and protein preparations from amaranth and quinoa seeds on the rheological properties of wheat-flour dough and bread crumb

Sándor Tömösközi, Lilla Gyenge, Ágnes Pelcéder, Tibor Abonyi, Regine Schönlechner, Radomir Lásztity

Czech J. Food Sci., 2011, 29(2):109-116 | DOI: 10.17221/45/2010-CJFS

The effects of amaranth and quinoa flours and protein isolates prepared from amaranth and quinoa seeds on the rheological properties of wheat flour dough and bread were studied using new recording instruments, the micro Z-arm mixer (for dough) and the SMS-Texture analyser (for bread crumb). The addition of 10% amaranth or quinoa flours did not cause significant changes in rheological properties. However, higher additions (20% and 30%) resulted in significant changes in stability, the degree of softening and elasticity. Substitution of wheat flour by amaranth or quinoa flours resulted in an increase of water absorption capacity. A significant reduction of specific volume and an increase of resistance to deformation (firmness) of the crumb of breads prepared from flour mixtures containing high percentages of amaranth or quinoa flours was observed. The addition of protein isolates did not significantly influence the main rheological parameters of dough, and bread crumb.

Comparative Analysis of Genetic Similarity between Perennial Ryegrass Genotypes Investigated With AFLPs, ISSRs, RAPDs and SSRs

Ulrich Kurt Posselt, Philippe Barre, Gintaras Brazauskas, Lesley Beryl Turner

Czech J. Genet. Plant Breed., 2006, 42(3):87-94 | DOI: 10.17221/3647-CJGPB

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).

Pig carcass quality in relation to carcass lean meat proportion

J. Pulkrábek, J. Pavlík, L. Vali¹, M. Vítek

Czech J. Anim. Sci., 2006, 51(1):18-23 | DOI: 10.17221/3904-CJAS

The objective of the study was to quantify differences in the carcass composition of pig carcasses with different lean meat proportions. Totally 132 carcasses with lean meat proportions ranging from 45 to 65% were analysed. The average lean meat proportion in the analysed set of carcasses was 55.38% (s = 4.319). The carcasses were classified into the groups according to their lean meat proportion (R, 45.0 to 49.9%; U, 50.0 to 54.9%; E, 55.0 to 59.9%; S, more than 60.0%). Carcasses from each group were cut into primal cuts and the main cuts (leg, loin, shoulder and belly with bones) were further separated into different tissues. Carcass value was markedly enhanced by the increasing carcass lean meat proportion. Average leg percentages in the groups R, U, E and S were 17.88% (s = 0.918), 19.32% (s = 0.889), 20.88% (s = 0.817) and 21.88% (s = 0.827), respectively. Average proportions of fat over leg expressed as percentages of leg weight in these groups were 5.82% (s = 0.402), 4.87% (s = 0.556), 4.05% (s = 0.479) and 3.21% (s = 0.321), respectively. Lean meat proportions of leg weight were improved from 84.93% (s = 1.136) in the group R to 88.12% (s = 0.986) in the group S. The most distinct differences were found in lean proportions of belly weight. The observed averages in the group R and S were 43.90% (s = 2.729) and 62.10% (s = 2.219), respectively. Actually, in carcasses with a high classification score the belly can be considered as a cut with the predominant muscle tissue. The results of the study proved the efficiency of carcass evaluation based on the lean meat proportion. Such a method can significantly contribute to the overall improvement of pig production.

Presence of the newly designated powdery mildew resistance Landi in some winter barley cultivarsOriginal Paper

Antonín DREISEITL

Czech J. Genet. Plant Breed., 2011, 47(2):64-68 | DOI: 10.17221/14/2011-CJGPB

In the last two decades, resistance to the powdery mildew pathogen has been investigated in a large number of barleys in the Czech Republic. Several tens of winter barley cultivars were identified with a resistance based on an unknown gene or unknown combinations of resistance genes. In this paper tests on 20 of these cultivars are presented. Thirty-two reference isolates of Blumeria graminis f.sp. hordei were used. All the 20 cultivars shared a particular, previously unknown resistance. Landi was the first cultivar registered with this resistance and it is recommended that this resistance be designated Ln. Isolates virulent to Ln were already found randomly in old European, and also in non-European pathogen populations, where cultivars possessing the resistance Ln were never grown. On the other hand, the resistance Ln has been highly effective even 13 years after Landi registration.

Parthenogenetic development of rabbit oocytes after electrical stimulation

A. Wierzchos

Czech J. Anim. Sci., 2006, 51(9):400-405 | DOI: 10.17221/3957-CJAS

The aim of this study was to determine the effect of electric pulses on the structural and functional condition of rabbit oocytes. The New Zealand White female rabbits at 3-5 months of age and at 3-4 kg body weight served as oocyte donors. Oocytes after flushing from the oviducts were placed between two electrodes in an electroporation chamber which was filled with a dielectric solution. Following a short incubation in B2 medium, oocytes were subjected to an electric pulse released by an electrical pulse generator. Oocytes were then incubated in 500 µl of B2 medium supplemented with 20% foetal calf serum (FCS) at 38°C in an atmosphere of 5% CO2 in air. Oocytes were cultured until the morula/blastocyst stage (approx. 72 h). The experiment was conducted using 430 oocytes obtained post mortem. In vitro cultured oocytes not subjected to an electric pulse were the control. Each group was subdivided into replications according to electric current intensity. The analysis of experimental variants shows that in the first variant all embryos developed to the morula stage but only 10% of them continued to develop to the blastocyst stage. In the second variant we observed that 5-10% of oocytes developed to the blastocyst stage after treatment with 2.0 and 2.5 kV/cm pulse but in the group of 1.0 kV/cm pulse 35% of oocytes developed only to the 2-12 b stage. In the third variant only 1 oocyte (5%) continued to develop to the blastocyst stage, but in the fourth variant oocyte development stopped at the morula stage. In the fifth variant, called an "extreme" one, oocytes stopped to develop at the stage of 2-12 b (about 25%) and the percentage of degenerated oocytes dramatically increased (about 60%).

Effects of a probiotic in combination with prebiotics on intestinal lactobacilli and coliforms and activities of bacterial enzymes in 1,2-dimethylhydrazine exposed rats

L. Strojný, A. Bomba, E. Hijová, A. Chmelárová, G. Moj¾i¹ová, I. Bertková, J. Koprovièová, M. Pomfy, V. Strompfová, M. Molokáèová

Czech J. Anim. Sci., 2011, 56(3):99-106 | DOI: 10.17221/56/2010-CJAS

Effects of the probiotic (PRO) Lactobacillus plantarum and of the combination of PRO and the prebiotic (PRE) inulin enriched with oligofructose (2%), and PRO with Lini oleum virginale (O) on counts of lactobacilli and coliforms and enzymatic activities in faeces of rats were studied. The rats (n = 60) were divided into 5 groups of 12 subjects. The animals were fed on a high fat diet (10%) for 8 weeks of experiment. Colon cancer was induced by the application of 1,2-dimethylhydrazine (DMH) twice a week in a dose of 20 mg/kg s.c. in groups G2-G5. The rats in group 1 (control 1) received a diet without any supplements. The rats in group 2 (control 2) received 1,2 DMH without any supplements. The rats in group 3 received PRO, group 4 PRO and PRE, and group 5 received PRO and O. A significant decrease (P < 0.05) of coliforms was found out after the application of PRO, PRO-O, and PRO-PRE in comparison with control group G2. Significantly higher (P < 0.05) counts of lactobacilli were determined after the application of PRO-O and PRO-PRE. Significantly lower (P < 0.001) activities of β-galactosidase, β-glucuronidase and α-glucosidase were observed in PRO, PRO-PRE and PRO-O, while in the case of the enzyme β-glucosidase the activity was lower only after the addition of PRO-O. The protective effect of lactobacilli was observed in the order PRO-O, PRO-PRE, and PRO. It was shown that combinations of PRO-O and PRO-PRE had a synergistic effect which was higher than the effect of administering only PRO.

Flower thinning of apple cultivar Braeburn using ammonium and potassium thiosulfate: Short communication

B. Miliæ, N. Magazin, Z. Keseroviæ, M. Doriæ

Hort. Sci. (Prague), 2011, 38(3):120-124 | DOI: 10.17221/57/2011-HORTSCI

Ammonium and potassium thiosulfate are used commercially or experimentally as flower thinners because they are considered user, environment and consumer safe. The thinning trials were conducted in 2009 and 2010, on three- and four-year-old Braeburn Mariri Red* trees. The chemicals were applied at 1%, 2% and 3% rates of ammonium and 0.5%, 1% and 1.5% of potassium thiosulfate. Both thinning agents reduced fruit set, but were more efficient in 2009, when applied at 20% full bloom, than in 2010, when they were applied at 80% full bloom. Flower thinning with ammonium and potassium thiosulfate increased the average fruit weight, but the highest chemical rates retarded fruit growth. Ammonium and potassium thiosulfate did not affect fruit shape and firmness, but they increased starch degradation, total soluble solids content and titratable acidity. The treatments increased the percentage of flower buds, except at the highest chemical rates, where leaf damage reduced flower bud formation. Ammonium or potassium thiosulfate application may be recommended as the first step in a chemical thinning program

Sugar beet as a raw material for bioethanol production

A. Hinková, Z. Bubník

Czech J. Food Sci., 2001, 19(6):224-234 | DOI: 10.17221/6612-CJFS

Overproduction of sugar causes a reduction in the acreage under sugar beet. That is why new non-food technologies for exploitation of agricultural products are sought. Utilization of beet for liquid fuel production could be one of them. The aim of experiments with sugar beet raw juice fermentation was to verify the possibility to return a part of distiller's slops back to the fermentation process and thereby to obtain stillage with higher content of dry solids. This would bring about energy savings during slops thickening and drying. Tests with recycling of different portions of stillage (20, 25 and 30%) back to the fermentation stage were carried out. No significant increase in dry solids content in mash was found and therefore no energy savings during thickening can be expected. The only savings can be made in water consumption that is replaced by slops.

Frost cracks and their effect on the stability of birch stands in the Kru¹né hory Mts.

E. Kula, I. Buchta, P. Stránský

J. For. Sci., 2006, 52(8):348-356 | DOI: 10.17221/4517-JFS

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 Kru¹né 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.

Changes of S-alk(en)ylcysteine sulfoxide levels during the growth of different garlic morphotypes

Jana Horníèková, Roman Kubec, Jan Velí¹ek, Karel Cejpek, Jaroslava Ovesná, Helena Stavìlíková

Czech J. Food Sci., 2011, 29(4):373-381 | DOI: 10.17221/3/2011-CJFS

The contents of three S-alk(en)ylcysteine sulfoxides (alliin, methiin, and isoalliin) were determined in the leaves, pseudostems, and bulbs of six garlic genotypes (two flowering plant morphotypes, two semi bolters, and two scape absent morphotypes) cultivated for five consecutive years at the same location. The average levels of alliin, methiin, and isoalliin were found to be as follows: 1.92, 0.44, and 0.07 mg/g fw in the leaves, 1.57, 0.27, and 0.08 mg/g fw in the pseudostems, and 1.71, 0.20 and 0.13 mg/g fw in the bulbs, respectively. No statistically significant year-to-year differences were observed between the samples. Furthermore, the total contents and relative proportions of S-alk(en)ylcysteine sulfoxides in various parts of the plants (leaves, pseudostems, bulbs and roots) were evaluated in detail during the whole vegetation period. It was observed that the total content of these amino acids gradually decreased in all parts except for the bulbs. In the bulbs, the total content initially decreased after planting but significantly increased in June and culminated before harvest. Analogous trends were also observed for alliin and methiin concentrations. On the other hand, isoalliin levels steadily decreased during the whole vegetation period in all parts of the plants.

A strategic look at global wheat production, productivity and R&D developments

P. G. PARDEY

Czech J. Genet. Plant Breed., 2011, 47(10):S6-S19 | DOI: 10.17221/3248-CJGPB

The 20th century began with a rapid ramping up of national investments in and institutions engaged with research for food and agriculture. As the 21st century unfolds, the global science and agricultural development landscapes are changing in substantive ways, with important implications for the funding, conduct and institutional arrangements affecting research for food and agriculture. Wheat improvement research is part of this broader agricultural innovation landscape. While there is a general consensus that the present and prospective future of the agricultural sciences bears little resemblance to the situations that prevailed in the formative years of today's food and agricultural research policies and institutions, many of these changes are poorly understood or only beginning to play out. This paper reports on selected new and emerging empirical evidence to calibrate the strategic private and public choices being made regarding wheat research in particular and food and agricultural R&D more generally.

Comparison of the growth pattern of black walnut (Juglans nigra L.) in two riparian forests in the region of South Moravia, Czech Republic

L. ©álek, P. Hejcmanová

J. For. Sci., 2011, 57(3):107-113 | DOI: 10.17221/61/2010-JFS

The black walnut (Juglans nigra L.), an introduced species into the Czech Republic, is planted for its production of valuable timber. A systematic study of the black walnut growth rate at different localities and consequently the creation of standard volume tables under Central European conditions therefore appear to be of high relevance. The aim of our study was to reveal the black walnut growth pattern in its pure stands in two riparian forests along the Morava and Svratka River (Strá¾nice locality and ®idlochovice locality, respectively). To describe and to compare relationships among diameter at breast height (dbh), tree height and age, we used a forest management plan and measured 573 and 670 trees in pure sample stands at Strá¾nice and ®idlochovice, respectively. We found out that the measured mean DBH and mean height were consistently higher in Strá¾nice, however the relationships of DBH to height, age to DBH, and age to height showed the same pattern at both localities. The mean heights of trees were 16.3, 24.1, 28.7, 31.9, and 34.5 m in 20, 40, 60, 80, and 100 year age classes and were consistently taller in comparison with other, mainly European, regions. Therefore our results suggest the high potential of black walnut in timber production in riparian forests in the Czech Republic, mainly in the South Moravian region.

Effect of storage on texture and microbiological stability of o-w emulsions with inulin

Pawe³ Glibowski, Monika Kordowska-Wiater, Agnieszka Glibowska

Czech J. Food Sci., 2011, 29(2):137-144 | DOI: 10.17221/213/2009-CJFS

The aim of this study was to characterise the effect of storage at 8°C on the texture and microbiological stability of oil-in-water solid emulsions containing inulin (20% w/w) and rapeseed oil (20% w/w). The samples were analysed within 24 h from the production and after 7, 14, 28, 42, and 56 days of storage. Whey protein isolate (3% w/w) or polyglycerol polyricinoleate (1% w/w) were used as emulsifiers and half of the samples were chemically preserved with potassium sorbate (0.2% w/w). Hardness, adhesiveness, and cohesiveness did not change significantly (p≤ 0.05) during storage. Most of the samples were microbiologically stable. Only the application of the protein emulsifier had an effect on the intensive growth of microorganisms. The shelf-life of low-fat chemically preserved products based on inulin can be established to be two months. Chemical preservation of the products with non-protein emulsifiers is not necessary. Sensory evaluation of spreads containing inulin revealed a significant decrease in smoothness and meltability in the mouth and good spreadability comparable with commercial products without inulin.

The survival of Escherichia coli upon exposure to irradiation with non-coherent polychromatic polarized light

D.M. Djurdjevic-Milosevic, M.M. Solaja, Lj.N. Topalic-Trivunovic, M.J. Stijepic, J.R. Glusac

Vet Med - Czech, 2011, 56(10):520-527 | DOI: 10.17221/3297-VETMED

The purpose of this work was to examine the influence of non-coherent polarized light upon the growth of Escherichia coli. Experiments were designed to test the main hypothesis that this kind of polychromatic light can produce decimal reductions in numbers of E. coli bacteria. Two strains of E. coli - isolated from ground pork and commercial culture E. coli ATCC 25922, were both exposed to light for 20, 30, 40 and 60 minutes. The source of non-coherent polarized light was a Bioptron-1 lamp (Zepter, Swiss) with the following technical characteristics: wavelength 400-2000 nm, polarization > 95%, and constant radiation dose 2.4 J/cm2 per minute. The result for both strains showed a slight increase in bacterial count in response to an irradiation time of 20 min and decreases in bacterial counts for irradiation times of 30, 40 and 60 min without characteristics of a decimal reduction. Bacterial counts after treatments displayed a linear relationship with the total count of bacteria before treatments as well as the percentage surviving bacteria and irradiation time. Data analysis (ANOVA two factors with replication) showed that the survival of bacteria was influenced significantly by duration time (P < 0.01), bacterial culture (p<0.05), and interaction between duration time and bacterial culture (P < 0.01). Neither E. coli ATCC 25922 nor E. coli isolated from ground pork showed a decimal reduction after irradiation with non-coherent polychromatic polarized light.

 previous    ...   75   76   77   78   79  80   81   82   83   84   ...    next