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The efficiency of leaf rust resistance genes in adult plants was studied on near-isogenic lines of Thatcher carrying known leaf rust resistance genes in the artificially inoculated leaf rust nursery of the Agricultural Research Institute of the Hungarian Academy of Sciences in Martonvásár over a five-year period (1997-2001). Eight of the wheat lines tested (Lr9, Lr19, Lr23, Lr24, Lr25, Lr29, Lr35, Lr37) exhibited little or no infection. Lines carrying genes Lr13, Lr44 and LrB were resistant in two years and those carrying Lr34, Lr38 and LrW in three years, after which they suffered moderate or heavy infection. Three lines (Lr12, Lr17, Lr32) proved to be moderately resistant. The majority of the wheat lines tested became heavily infected.

In field trials in 1998-2000, ten varieties of the world collection of birdsfoot trefoil (Lotus corniculatus) were evaluated for herbage and hay yields. In all the years of testing yields from three cuttings and total annual production were evaluated. In 1999, seed yield was also recorded. As a control, alfalfa (Medicago sativa) variety was included in the experiment. The test varieties showed good productivity in the first and especially in the second year of testing, most of them exceeded alfalfa in herbage yield in individual cuttings and in total productions. As for hay yield, the differences were not so great. Local varieties showed very good productivity, predominantly in herbage yields. Of foreign varieties, the best herbage, hay and seed yielder was the Hungarian variety Puszta. There were no statistical differences in seed yield between the varieties. The yields were, however, relatively low.

In 1999-2001 sulfur and sulfate concentrations were studied in expanded young leaves of rapes of the line variety Lirajet and hybrid variety Pronto at the onset of stem elongation (DC 30), flowering (DC 64) and early maturity (DC 70) in different localities of the Czech Republic. Except the S-deficient site the concentration of total sulfur and sulfates in leaves considerably increased in higher growth stages. A less steep increase in S concentration in leaves was associated with rather humid growing season, especially with April precipitation. Great time variations in sulfur concentrations in leaves signal a possibility of diagnostic misinterpretation of plant analysis without exact definition of growth stage. The shape of trend of variations in S concentration in leaves indicates the S nutritive state of the site and the intensity of upward transport of sulfates with soil moisture in the crop nutrition with sulfur. Good yields of rapeseed were connected with minimum concentration of total sulfur 0.5%, and sulfate sulfur 0.2% in leaf dry matter at DC 30. The proportion of sulfates in total concentration of sulfur in rape leaves ranged from 30 to 60% at the onset of stem extension and it increased in higher phenophases. At flowering, sulfates accounted for 80% and more at sites where sulfate uptake from the soil environment was not problematic. Besides the S-soil test, the results of investigations indicate the importance of CEC value of soil for the preventive diagnosis of S-nutrient state of the site.

A survey of development and prospects of the utilisation of doubled haploid techniques in rapeseed breeding in the world and in the Czech Republic is presented. The first utilisation of spontaneously occurred haploids from Brassica napus inbreeding programmes is described. The development of techniques of anther and later microspore culture is outlined. Special emphasis is given to the practical use of doubled haploids for the improvement of the effectiveness of breeding new productive cultivars. Some partial results of evaluation of yield parameters and resistance to important diseases in the obtained doubled haploid lines of winter oilseed rape are shown. The literary review and present results indicate, that the doubled haploid technique can be effectively used for the development of homozygous oilseed rape lines as an alternative to conventional methods.

The contribution firstly mentions a determination of possible approaches to the problems of regional development. The contribution content is the characteristics and comparison of the regional policy level in the European Union and the CzechRepublic. In the European Union, this policy has developed for a long time and it has been modified to the form which it has at the beginning of the 21st century. In this, it is a continuous process. On the contrary, in the Czech Republic during directive management, regional policy was not formulated and most of decisive processes were centralised. Since the beginning of 90ies, significant changes have taken place and in 2000 it was possible to say that the necessary presumptions for the use of efficient regional policy principles had been created.

The foreign agri-food trade has showed an unsuitable development for the Slovak Republic during the 1999-2001s. The negative balance for the competitive commodities is increasing. These are the commodities for the production of which the SR has suitable natural conditions. The contribution deals with the selected competitive commodities in the kilogram prices. The study shows the decreasing tendency of kilogram prices in import and the increasing tendency in export. Higher export price is the consequence of the higher value added and thus also higher revenues.

Ergot, caused by the fungus Claviceps purpurea (Fr.) Tul., belongs to the main constraints in seed production of Kentucky bluegrass (Poa pratensis L.). The level of ergot occurrence depends on the weather conditions during the growing period, harvest year, storage conditions of seed, and post-harvest treatment. The degree of resistance of the grown cultivar plays an important role. Based on greenhouse trials with four different ergot populations (Zubří, Czech Republic; Leutewitz and Munich, Germany; Pullman, Washington, USA) during 3 years, we found pathogenicity to be one of the most important factors. There were significant differences in the amount of ergot bodies formed between the Central European populations (Zubří, Leutewitz) and the American one from Washington State. The degree of pathogenicity has a major impact on the occurrence of ergot sclerotia in seed of Poa pratensis.

The genus Armillaria belongs to basidiomycetes and has been known to induce root rot disease and to cause extensive economic losses to a forest crop. We analysed about 40 isolates of Armillaria collected in Czech Republic by PCR and restriction analysis using gel electrophoresis and ion-exchange HPLC. Restrictase Hinf I was able to discriminate all investigated Armillaria species. The sensitivity and resolution of HPLC method was better than that performed by gel electrophoresis. HPLC was able to detect some heterozygous. The results prove the similarity of the species A. borealis, A. cepistipes, A. gallica, A. ostoyae in difference of A. mellea and A. tabescens.

We characterized the genetic diversity of seventy-three C. lindemuthianum isolates collected from 10 different countries by Amplified Fragment Length Polymorphism (AFLP) analysis. The results of this research highlighted the fact that there is huge variation in the genetic diversity between isolates from different countries. The molecular profile of the isolates showed correlation with geographic origin of the isolates.

B. salicis was monitored in willow stands, sampling trees with and without watermark disease. The study focused on Salix alba and S. fragilis. B. salicis - presence was shown not to be restricted to diseased trees. With a B. salicis-specific PCR, B. salicis was frequently detected in the wood of healthy willows. This phenomenon was further studied with PCR-DGGE of endophytic bacterial populations in healthy and diseased willow. B. salicis concentrations were fluctuating during the year, synchronized with tree activity. Water stagnation in the wood as in winter was associated with a high B. salicis concentration, while the sap stream in active trees drained B. salicis from the wood vessels towards the leaves. We concluded that disease risk can not be assessed by testing the presence of B. salicis.

In the framework of PVS eradication from breeding materials of Czech potato cultivars, the systematic research was devoted to: susceptibility of cultivars, occurrence of PVS in imported and domestic materials, and to maintenance of virus-free basic grades potatoes on breeding stations. In the field-exposure trials was proved high level of susceptibility of most cultivars to PVS and by contraries, gradualy increased proportion of maintained virus-free cultivars of foreign, as well as domestic origin. Nevertheless severe infestation still persist in some of them. The contemporary situation with maintenance of virus-free basic material in CR was demonstrated.

The monitoring was carried on in the years 1996-2000 in the polyfactorial P-A field trial in Lukavec, Pelhřimov district. The given locality is characterized by low fertility sandy-loamy cambisoils, by long-term average annual rainfall of 653 mm, by average annual temperature of 7°C and its altitude is 620 m. The field trial included different organic fertilizations; graduate N-doses, different soil tillage as well as different forecrops. It manifested in this group of field trials that the forecrop value of red clover and dung manured potatoes before winter wheat was practically the same in the given locality. The optimal N dose for potato yields was about 80 kg N.ha^-1. In oats the yields after red clover with using the Horsch system in spring were significantly lower than after embedding of red clover in autumn. In cereals, graduated N doses increased the numbers of ears (panicles) per m2, but the mass of 1000 grains often decreased. In addition, N content in grain and straw increased with N doses, while pH annually decreased by 0.1 to 0.4.

Parameters characterizing N mineralization and nitrification were measured in soils of ten monitoring areas of the basal soil monitoring carried out by the Central Institute for Supervising and Testing in Agriculture. A remarkable seasonal cycle was found only for nitrate concentrations that reached their maxima in the spring (April-June), and late summer and/or autumn, starting in August. Ammonium ions were nitrified immediately after fertilizer application. Anaerobic N mineralization represented a variable parameter, which was not directly affected by mineral N fertilizers. Nitrification measured by means of one-week incubation was significantly stimulated by N fertilizers confirming that substrate availability was a limiting factor of this process. Short-term nitrification activity (SNA) showed no remarkable seasonal fluctuations, which meant that the potential nitrification rate remained relatively constant during the season. Urease activity was mostly constant during the year and was only slightly related to N mineralization.

B. bassiana strains isolated from 0. nubilalis were tested against the larvae of 0. nubilalis and coccinellid beetles in laboratory conditions (25°C). The first dead 0. nubilalis larvae were observed 48 hours after the application. During the first five days after the application, the efficiency of spore suspension was significantly higher than the efficiency of dry spore formulation. Spore suspension killed more than 50% of larvae after 72, or 96 hours. After dry spore formulation was used, more than 50% of larvae were killed during 96, or 120 hours. B. bassiana killed 50% of coccinellid larvae during 48 hours. After anot her 24 hours 83.3% (strain SK78), or 100% (strain SK99) coccinellid larvae were killed by fungus. More than 50% of dead adults of Coccinella septempunctata L. and Propylea quattuordecimptmctata (L.) was found 72-120 hours after application of fungus. This mea ns that B. bassiana was not adapted specifically to original host and killed effectively the adults and larvae of Coccinellidae. Different behaviour probably allows the coccinellids to escape from fungal infection in natural conditions

Experimental groups of pigs were treated orally with 120 mg (Group O 120), or 480 mg (Group O 480) of iodine per animal, or intramuscularly with 240 mg (Group I 240) of iodine per animal. Iodine was administered in the form of iodised fatty acid esters (IFAE). The treatment resulted in significantly increased iodine concentrations in tissues and a single dose was sufficient to meet the requirement for the whole fattening period (180 days). Urinary iodine concentrations in all the experimental groups were higher than in the control group C receiving iodine only from conventional feed. Urinary excretion of iodine between days 2 and 5 was more distinctive in orally treated than in intramuscularly treated animals (Figure 1). Iodine concentrations at the end of the fattening period (day 180) were higher in the treated than in the control groups. The treatment effect was more marked in Groups O 480 and I 240 than in Group O 120. The dynamics of blood serum iodine concentrations was similar to urinary concentrations (Figure 2). Mean thyroid gland weights in the groups O 120, O 480, I 240, and C were 9.19, 8.51, 7.10, and 12.01 g, respectively. An opposite tendency was observed for iodine concentrations in thyroid gland dry matter (Figure 3). No effects of any of the treatments on total protein, albumin, total lipids, or cholesterol concentrations in blood serum were observed. Group C showed lower tissue iodine concentrations than any of the experimental groups. The only exception was hepatic tissue in which approximately the same iodine concentrations were found in all the groups. Data obtained in Groups O 120, O 480, and I 240 indicate that decisive for tissue concentrations was rather the dose of iodine than the route of administration. Iodine is stored above all in the thyroid gland and adipose tissue. As can be seen in Figure 4, its concentration was higher in muscles with a higher proportion of fat (neck) than in lean muscles (ham).

The bread-making quality of forty commercial winter wheat samples, grown in the western region of the CzechRepublic, and their flours (white flours with ash content of about 0.5%) prepared in a commercial mill was studied. Standard analytical methods (ash and protein content, wet gluten), amylolytic activity measurement (falling number), rheological investigation (alveograph, gluten index), sedimentation test and laboratory baking test were used for characterization of wheats and flours. In addition NIR method was used to calculate ash, wet gluten, sedimentation value and protein content. Statistically significant correlations were found practically between all tested quality parameters of wheat and corresponding flour samples. However, the strongest correlation (r = 0.69-0.70) significant at 0.01 level exists between specific bread volume and protein and wet gluten content, determined both by standard or by NIR methods.

The objective of this work was the morphologic analysis of apoptosis of neutrophilic granulocytes (hereinafter referred to as neutrophils) in scanning electron microscopy (SEM) in comparison with morphological features distinguishable by light microscopy. This study was performed on 12 bovine virgin mammary glands washed with physiological buffered solution (PBS) prior to the induction of cell influx by PBS. Twenty-four hours after influx induction the cell suspension was obtained by the lavage of mammary glands with PBS. The particular lavages were cytologicaly and bacteriologicaly examined. all bacteriological examinations were negative. Mononuclear phagocytes (MoP), lymphocytes and neutrophils were distinguished in the cell suspension of the lavages by means of light microscopy. The neutrophils predominated in differential cell count. Neutrophil population showed some signs of structural features typical for the process of apoptosis that were distinguished in haemocytometer and light microscopy on stained microscopical smears. The process of apoptosis consisted of three structurally different stages: karyopyknosis, zeiosis and the stage of apoptotic bodies. These stages of neutrophil apoptosis were distinguished also by SEM. Karyopyknotic neutrophils assumed spherical shape while they lost all of their superficial pseudopodia. Neutrophils in zeiosis stage showed prominent surface protumberances, bubble-shaped vesicles causing a bizarre deformation of the cells. After the membrane vesicles had split off, they began to form spherical formations (apoptotic bodies). On the basis of neutrophils. specific structural properties it could easily distinguish all the three stages of neutrophil apoptosis by means of SEM technique as well as other morphological methods.

The astringent taste is important for the sensory quality of beverages. Perception thresholds of two important astringent compounds - tannic acid and (+)-catechin were determined using two procedures. The concentration-intensity dependence was linear at low concentrations and up to medium intensities of the astringent taste if unstructured graphical scales were used, but the saturation threshold was soon attained in the case of tannic acid. Recording the results on printed forms gave similar results as using a touch-sensitive monitor. The optimum tasting was achieved at swallowing after degustation of 5 s. The duration of degustation increased the intensity. The astringent flavour was suppressed by sugar, but was not significantly influenced by ethanol, citric acid or quinine hydrochloride. Astringent substances were accurately perceived and rated in wine, tea infusion and orange drink, but the increase of astringency was smaller than in model solutions. The astringent taste was easily distinguished from the bitter taste.

The aim of this paper was to register the domestic animals appearing in the iconography of Christian saints and to explain their association. The source of knowledge was literature dealing with hagiographies of saints, sacral iconography and liturgy along with visiting churches, monasteries and museums throughout Croatia. After research in sacral literature and works of art lasting several years, it was observed that the following domestic animals appear as accompanying about seventy Christian saints: bees, bull, camel, cow, dog, donkey, goose, dove, horse, lamb, pig, sheep, steer. Reasons and explanations of their association are most often in practical relations (the animal serves and helps the man). However, in the animal, the most varied symbolic, especially ethical and morality messages are personified very often. Especially interesting are saints honoured as patrons of particular animals and of professionals occupied with animals. In human medicine, they are most frequently protectors from zoonoses, too. In some cases, animals are attributed to saints because of the linguistic association resulting from similarity of the names of animals and saints. In the same way, domestic animals are present in sacral art as a part of ambient decoration, too. In addition, it can also be interesting from the historical and ethnic veterinary point of view. Presented examples show how, by interdisciplinary approach to sacral art and tradition, we can come to other numerous findings surpassing mere religious messages. In this case, these are contributions to the history of veterinary medicine in the widest sense.

Total content and composition of essential oils in caraway seed (Carum carvi L.) from a selection of caraway varieties grown in different production areas were determined after supercritical fluid extraction (SFE) and steam distillation. Different procedures of sample pretreatment (homogenization) and methods of isolation were compared from the point of view of efficiency, reproducibility and accuracy. The effect of storage period was also examined.

Effects of sodium humate (HuNa), containing 61.9% of humic acids in dry matter, on utilisation and retention of dietary iodine were investigated in balance experiments carried out in pigs. A control group was fed a commercial diet containing 0.1 mg of iodine per kg. The daily intake of iodine was 129.2 µg per animal or 4.08 µg per kg live weight. The recommended intake of dietary iodine is 0.25 to 0.30 mg per kg at 88% dry matter. The experimental group (HuNa) was fed the same diet supplemented with 3% of sodium humate which contained 0.5 mg of iodine per kg at 90.04% dry matter. The supplementation increased the daily intake to 141.4 µg per animal, or 4.45 µg per kg live weight. The supplementation of HuNa increased significantly the amount of iodine excreted in faeces (53.2 ± 11.0 vs. 43.0 ± 6.47 µg per animal per day; P < 0.05) and nonsignificantly the urinary iodine excretion (31.8 ± 8.93 vs. 29.0 ± 11.3 µg per animal per day). Differences between the HuNa and the control groups in blood serum iodine concentrations (18.8 vs. 18.1 µg per litre) and urinary iodine concentrations (32.5 vs. 34.4 µg per litre) were nonsignificant. It is evident from the concentrations that the pigs suffered from a serious iodine deficiency. Compared with controls, the HuNa group showed significantly higher triiodothyronine concentration (P < 0.05) and nonsignificantly lower thyroxine and iodine concentrations in blood serum. Dietary iodine utilisation was lower in the HuNa than in the control group (62.3 vs. 66.6%). The results show that utilisation of dietary iodine was limited and that sodium humate (humic acids) reduced iodine utilisation and retention and affected also other parameters indicating their goitrogenic effects.

Distribution of leukocyte types present in virgin bovine mammary glands was analysed in dot plots obtained by flow cytometry (FACS) of samples collected from 10 non-pregnant heifers after induction of leukocyte influx. Changes of percentage of leukocyte types during development and resolution of induced influx in comparison with blood leukocyte pattern allow identification of these cell types on FACS dot plot. The positions of mammary gland granulocyte and lymphocyte regions were identical with those of the corresponding peripheral blood cells. Two basic morphologically distinct types occupying separate regions in dot plots were observed in the population of mononuclear phagocytes (MoP): non-vacuolised monocyte-like macrophages (MoMAC) and vacuolised macrophages (MAC). Influx resolution was characterised by a marked shift of the MoMAC region towards that of MAC recognisable in dot plots by a separate region of intermediate MoP forms. The study provides a pattern of dynamics of percentages of mammary gland leukocyte types during influx development and resolution as imaged by FACS.

The bionomics of Acarus siro was studied at 18 and 20°C and 70 and 80% R.H. on wheat germs, linseed, rapeseed and sunflowers to obtain data for optimisation of biological control of stored product mites on oilseeds. Wheat germs were used as a control substrate as they were considered optimal for development of A. siro. The development of eggs and larvae was longer than that of protonymphs and tritonymphs. Wheat germs appeared to be a better substrate for the development of mites than oilseeds. Generally, the life span of females as well as the oviposition period was shortest on wheat germs while longest on sunflower; also, at the higher temperature the female life span was shorter. The maximum number of eggs laid by a single female (356) was recorded on wheat germs at 20°C and 80% R.H. The development was significantly shorter at 20°C than at 18°C regardless of humidity. There were no significant differences between the effects of the tested oilseeds.

Phenolic compounds were extracted from rye caryopses with 80% (v/v) methanol. Phenolic acids were determined as free compounds and those liberated from soluble esters and glycosides. The analyses were performed using a Waters HPLC system equipped with a diode array detector (DAD). The following free phenolic acids were found: p-coumaric, ferulic and sinapic; the phenolic acids liberated from soluble esters were as follows: vanillic, caffeic, p-coumaric, ferulic and sinapic; and those liberated from soluble glycosides were the following: vanillic, p-coumaric, ferulic and sinapic. In rye caryopses, phenolic acids were chiefly in the form of soluble esters. A diode array detector was especially useful for the determination of vanillic acid: the UV spectrum of this compound showed a maximum at 260 nm whereas UV spectra of other phenolic acids were characterised by maxima at longer wavelengths.

Two monoclonal antibodies (MAb) to the outer structural protein E2 (spike peplomeric protein) and two MAb to the inner capsid protein N of bovine coronavirus (BCV) were prepared and identified by Western blotting to be used for increasing the specificity and sensitivity of BCV detection. The MAb were checked by the haemagglutination inhibition test and immunoperoxidase tests and no cross reactivity with rotavirus was demonstrated by the immunoperoxidase test and ELISA. A mixture of all the four MAb at predetermined optimum concentrations was first used in sandwich ELISA and then, in combination with an anti‑coronavirus polyclonal antibody, for the development of a simple and rapid immunochromatographic test (ICT). The results of which can be read visually within 10 min. The inclusion of MAb into ELISA and ICT allows the detection of both intact and incomplete BCV virions. ELISA and ICT were used in the examination of a set of 74 faecal samples collected from calves suffering from diarrhoea. ELISA, used as the golden standard verified by electron microscopy, detected BCV in 15 samples (20.3%) and ICT in 16 samples. Three of the ICT‑positive samples were negative by ELISA. On the other hand, two of the 58 ICT‑negative samples were positive by ELISA. Sensitivity and specificity of ICT were 94.9% and 86.7%, respectively

A simple 1-D mathematical model for prediction of local temperatures in a layer of solid material during microwave heating (Houšová et al. 1998) and a sensitivity analysis were used to evaluate the influence of process and material parameters on vertical temperature profiles in a layer of material during heating. The results of calculations are presented in graphs and discussed. The incident microwave power and heat capacity and density of heated material are parameters with great effect on all local and average temperatures and local and average heating rates. The shape of temperature profile is influenced only to a small extent by a change in the value of applied microwave power and also in the value of heat capacity or density of heated material. The whole profiles shift to higher or lower temperature values when the incident microwave power is changing. The distribution of applied microwave power between the upper and bottom layer surface very much influences the shape of the profile and the values and position of the highest and the lowest temperature in the layer. Depth of penetration and thermal conductivity of heated material influence on the shape of temperature profiles and the temperature spread in the layer (evenness of temperature distribution). Effect of penetration depth also depends on the relation to the layer thickness - its effect increases with the increasing layer thickness. At the low values of penetration depth relative to the layer thickness, an uneven temperature profile is to be expected. Effect of thermal conductivity value on temperature profile depends on the time of heating. Because of a short time of microwave heating, the effect of this parameter on temperature distribution is smaller compared to the conventional heating methods. At the beginning of heating its influence is quite negligible. Temperature of the air surrounding the layer and intensity of heat exchange between the air and layer surface are parameters with only small local effect on temperature distribution.

: During the 18-year period (1974-1991), the lymphocytic thyroiditis with the finding of serum autoantibodies against thyroglobulin was diagnosed in 180 Beagle dogs (92 males and 88 females). In 107 of them (56 males and 51 females), hyperplasia of parafollicular cells was concurrently encountered. In further 11 cases (3 males and 8 females), solid cellular structures were found in the thyroid parenchyma, in 4 females combined with unilocular or multilocular lymphoepithelial cysts. Grimelius stain revealed the presence of parafollicular cells even at the periphery of cellular nests. Using the lectin histochemistry with Maackia amurensis agglutinin (MAA),Sambucus nigra agglutinin (SNA) and Tritrichomonas mobilensis lectin (TML), the presence of sialylated molecules was demonstrated in the cell membranes and perinuclear cytoplasmic regions of parafollicular cells that formed hyperplastic nodules or were interspersed in "solid cell nests".

The objective of this study was to determine the effect of vitamin E and selenium administration on glutathione peroxidase (GSH-Px) activity and selected parameters of cellular immunity (metabolic activity, phagocytic activity, lymphocyte blastogenic response). Nine pregnant sheep with body weight of 42 to 66 kg were divided into two groups. Before lambing, the first group (n = 5) was given subcutaneously 5 mg vitamin E and 0.4 mg selenium per kg body weight while the second group (n = 4) was given no treatment and served as control. Blood samples from all sheep were collected before the treatment, 14 days after lambing and 30 days after lambing. Whole blood GSH-Px activities were significantly higher in the vitamin E and selenium treated sheep than in the control in the samples taken 14 days after lambing and 30 days after lambing (P < 0.01; P < 0.001, respectively). The evaluation of immunological parameters showed declines in immunological parameters measured on days 14 and 30 after lambing. The administered preparation led to significant effects (P < 0.001; P < 0.05) on phagocytic activity index of leukocytes and phagocytic activity index of neutrophils, respectively.

This experiment was conducted to evaluate the effect of vitamin C (L-ascorbic acid) and chromium (chromium picolinate, Cr Pic) on egg production, some egg characteristics, and digestibility of nutrients in laying hens (Hy-Line) reared under a low ambient temperature (6.2°C). Two hundred and ten laying hens (32 week-old) were divided into seven groups, 30 hens per group. The treatment groups were designed in a 2 × 3 factorial arrangement using two levels of vitamin C (125 and 250 mg/kg of diet) and three levels of chromium picolinate (200, 400, or 800 µg/kg of diet), and control group was fed basal diet. The highest values of performance were obtained if 250 mg/kg vitamin C was supplemented with either 400 or 800 µg Cr per kg of diet. An interaction between vitamin C and chromium for egg production (P = 0.05) and feed efficiency (P = 0.02) was detected. Similarly, egg weight, specific gravity, egg shell thickness, egg shell weight and Haugh unit improved with diet containing 250 mg vitamin C and either 400 or 800 µg Cr per kg of diet (P £ 0.05). Digestibility of dry matter (DM), ash, organic matter (OM), crude protein (CP), and ether extract (EE) were higher with higher dietary vitamin C (P £ 0.05) and also with higher Cr (P £ 0.05). There were no interactions between vitamin C and chromium detected for any parameters measured for egg quality in terms of egg weight, specific gravidity, egg shell thickness, egg shell weight and Haugh unit and digestibility of nutrients (P ³ 0.28). Data obtained in the present study shows that a combination of 250 mg vitamin C and 400 µg chromium per kg of diet gave the best results in laying hens reared under a low ambient temperature and a conclusion is suggested that such a diet can be considered as a protective management practice in poultry to alleviate, at least in part, the depressive effect of cold stress on poultry performance.