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  • Author or Editor: L. Bárdos x
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The present study was designed to investigate the effect of a one-month feeding of retinyl acetate (RA) on the retinol (ROL), retinyl palmitate (RP) and (-carotene (BC) levels in the blood, testicles and ovarian follicles of adult Japanese quails. The basal diet (containing vitamin A at 10 × 103IU/kg) was supplemented with 100 ×, 500 × and 1000 × 103IU/kg RA in Groups I, II and III in both sexes. Plasma vitamin A levels rose in all groups. The elevations were caused basically by the RP fraction. The ROL concentration increased only slightly, indicating saturation of the blood binding/transport system. Plasma BC was depressed in both sexes. RA feeding resulted in high RP concentration in the genital organs (testicles and ovarian follicles), indicating subclinical hypervitaminosis, while the BC content of genital organs decreased considerably. The retinoid and BC concentration of ovarian follicles (F1-F5) was in the same range, indicating continuous retinoid and carotene transport during the fast maturation period. Retinoid content of the genital organs was higher in layers than in roosters. BC deposition was decreased both in the testicles and in the follicles, indicating a competition between RP and BC for the storage capacity of organs.

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Abstract  

Formation of oxidizing and reducing radicals has been studied by pulse radiolysis of [Fe(CN)6]4––BrO 3 –CN system in ethylene glycol — water solvent mixture. Oxidizing ·BrO2 and BrO radicals formed by electron scavenging with ·BrO 3 were identified and their reactions were investigated. The reaction of hydroxyl radicals with ethylene glycol leads to formation of reactive radicals with reducing properties and of compounds which reduce slowly in dark the ferricyanide formed in the reaction of ·BrO2 radical with ferrocyanide.

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An experiment was conducted to study the effect of large-dose (-carotene supplementation on blood retinoid and (-carotene levels as well as on the progesterone secretion of the granulosa cells in Japanese quail. Laying quails were assigned to three dietary groups. The control group (Group C) received the basal diet (laying feed containing 9000 IU vitamin A/kg). In the treated groups (Groups BC1 and BC2) the basal diet was supplemented with 102and 103mg/kg (-carotene (BC), respectively. At the end of the two-week feeding period, 10 birds from each group were euthanised. Blood samples were analysed for retinol, retinyl palmitate and (-carotene concentrations. Granulosa cells were isolated from ovarian follicles (F1and F2), and PMSG-inducedin vitroprogesterone (P4) secretion was measured. Similar retinol concentrations were found in both (-carotene supplemented groups, indicating saturation of the retinol-transporting system. (-carotene supplementation was accompanied by hypercarotenaemia, but did not increase the retinyl palmitate levels in the blood. PMSG-induced P4production of the granulosa cells decreased significantly in Groups BC1 and BC2 in a dose-dependent manner.

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The relationship of retinoid and carotenoid metabolism with caecotrophy was studied in adult female New Zealand White rabbits kept in individual metabolic cages. Caecotrophy was prevented by the use of plastic collars. The dry matter, crude protein, fibre, fat and ash contents of hard and soft faecal samples were determined. The retinoid (retinol and retinyl palmitate) and carotenoid (canthaxanthin, β-carotene, β-cryptoxanthin, lutein and zeaxanthin) levels of the blood, liver, kidney, caecal content and faeces were also measured by high-performance liquid chromatography (HPLC). The prevention of caecotrophy resulted in a significant decrease of blood retinol (P < 0.001) and retinyl palmitate (P < 0.01) concentration but it did not cause any significant change in the retinol and retinyl palmitate contents of the liver and kidney. The caecal content (25.78 ± 6.87 µg/g) and the soft faeces (34.52 ± 10.48 µg/g) contained the retinoids in similar amounts. Various carotenoids were found in considerable amounts in different types of faeces, while in the tissues (blood, liver and kidney) these pigments did not occur in substantial amounts. Total carotenoid concentration was similar in the caecal content (11.23 μg/g) and in the caecotroph (13.85 μg/g). On the basis of the results it can be assumed that the retinoid content of rabbit feed could be lowered in the presence of adequate caecal function and caecotrophy.

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Authors: J. Janan, L. Bárdos, Mária Karsai, Gabriella Ágota, Péter Rudas, J. Kozák and L. Bódi

The susceptibility of geese of different genotypes and sexes to force-feeding, some plasma biochemical parameters (thyroid hormones, cholesterol, retinoids, total protein and albumin) of force-fed geese, and the relationship between force-feeding, fat storage and the above-mentioned parameters were studied. Sixty (30 male and 30 female) geese of three genotypes (Hungarian, Landes and their crossbred called Babat Hybrid) were divided in two groups at 12 weeks of age. Geese in one group (5 males and 5 females from each genotype) received mixed feedingad libitum. Birds in the other group were force-fed with maize. After 3 weeks all birds were bled, blood samples were taken, and the above-mentioned plasma parameters were determined. Thyroxine (T4) levels were significantly lower in force-fed (11.6 ± 3.5 ng/ml) than in control geese (22.7 ± 4.09 ng/ml). Plasma triiodothyronine (T3) level was also lower in the force-fed than in the control group, but the difference was not significant (1.87 ± 0.23 ng/ml and 2.11 ± 0.28 ng/ml, respectively). Plasma total protein (TP, 45.2 ± 4.5 g/l), albumin (ALB, 16.51 ± 2.8 g/l), (-carotene (BC, 3504 ± 3107 µg/l), retinol (ROL, 1160 ± 505 µg/l), retinyl palmitate (RP, 1745 ± 405 µg/l) and total cholesterol (TCh, 4.32 ± 0.55 mmol/l) levels were elevated in the force-fed group as compared to the control (TP = 36.4 ± 5.1 g/l, ALB = 15.6 ± 0.9 g/l, BC = 1657 ± 1681 µg/l, ROL = 687 ± 375 µg/l, RP = 1398 ± 607 µg/l, and TCh = 2.83 ± 1.98 mmol/l). All differences were significant except those found for albumin and (-carotene. No significant sex- or genotype-related effects were observed for these parameters.

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Authors: Klára Oppel, L. Bárdos, A. Ferencz, Hajnalka Lakner, Judit Simon, Kriszta Temesváry, Krisztina Karchesz and Margit Kulcsár

Serum/plasma fructosamine (SeFa) concentration is a reliable indicator used in human diabetic control. Tests for monitoring the carbohydrate/energy metabolism of (farm) animals are less commonly performed in veterinary laboratories, since most of the reliable determinations, both automated and manual, are relatively expensive. The aim of this study was to develop a precise, money- (and time-) saving automated micro method for measuring SeFa. ELISA microplates (20 µL samples and 200 µL reagents) and an automatic microplate autoreader were used. The classical nitroblue tetrazolium (NBT) stain reagent solution of Johnson et al. (1982) was modified using a SIGMA reagent to render it stable for up to one year. SeFa concentrations measured by the new method in 30 human blood plasma samples were compared with values obtained by the standard (generally used) LaRoche kit procedure. Fifteen cow, 13 dog and 18 chicken plasma samples were assayed by the new automated ‘micro’ method as well as by the manual test tube ‘macro’ method commonly used earlier. The modified reagent was applied for both methods. The coefficient of correlation (r) between the results obtained by the two methods was consistently between 0.94 and 0.98 (p < 0.001).

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Authors: Melinda Zomborszky-Kovács, L. Bárdos, H. Bíró, S. Tuboly, Erzsébet Wolf-Táskai, Á. Tóth and P. Soós

The effect of synthetic beta-carotene and synthetic nucleotide base on daily weight gain, feed consumption and certain haematological, biochemical and immunological parameters of piglets were studied in a 3-week experiment. Beginning one week prior to weaning, the diet fed to one experimental group of piglets was supplemented with 10% Rovimix Beta-carotene at 875 mg/kg of diet. Synthetic uracil and adenine (98%, Sigma-Aldrich) were mixed into the diet of the other experimental group at doses of 500 mg/kg of diet for each substance. The control group received the basic diet without any supplementation. The changes observed over time in the haematological parameters and in certain biochemical variables could be regarded as physiological. By day 21 of the experiment, beta-carotene supplementation had significantly lowered the neutrophilic granulocyte percentage and elevated the lymphocyte percentage, while in the other two groups a change of opposite tendency occurred. At the end of the experimental period there was a decrease in plasma vitamin E concentration due to carotene supplementation (control: 6.1 ± 1.5, nucleotide: 6.3 ± 2.5, carotene: 2.3 ± 1.5 mg/L). Lymphocyte blastogenesis induced by phytohaemagglutinin and concanavalin A increased by 50 and 130%, respectively, in the nucleotide group and by 60 and 30%, respectively, in the carotene group, while it did not change in the control group. The supplements exerted no positive effect on the in vivo cellular immune response.

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