[Long-term exposure of broiler chick to PCB--clinical and biochemical changes]. / Dlhodobá expozícia brojlerových kurciat PCB--klinické a biochemické zmeny.

In view of preventive human and veterinary medicine negative effects of PCB are serious mainly with respect to their stability in food chain. A low degree of biotransformation in living organisms and PCB transfer through food chain have resulted in the ban on PCB production and in restriction of their use. Important restriction measures concerning the use of PCB-based products were already taken in the eighties. In spite of the ban on PCB production in this country (1984), their inventories along with contaminated refuse make around 10,000 tons. The data indicate the existence of sources of food chain contamination. Information campaign as well as targeted PCB monitoring are important components of prevention of environmental contamination. The originally monitored PCB sum has currently been replaced by a system of monitoring oriented to particular PCB congeners. The objective of this paper is to present clinico-biochemical changes observed in broiler chicks after a long-range exposure to a relatively low rate of original commercial types of PCB. Sixty one-day cockerels Hybro (paternal line) were included in a trial. The chicks were housed in boxes with deep litter under continuous lighting. They had free choice of feed and water. Control and experimental groups contained 30 broiler chicks each. A PCB blend (Delor 103 and Delor 105--original commercial products of PCB from Chemko Strázske) were added at a concentration of 50 mg/kg feed to the diet of experimental group. Numerous clinical and biochemical parameters were investigated in the conditions of long-range applications (1-42 days).(ABSTRACT TRUNCATED AT 250 WORDS)

[Long-term exposure to PCB in broiler chickens--metabolic and immunotoxic effects]. / Dlhodobá expozícia brojlerových kurciat PCB--metabolické a imunotoxické úcinky.

Even though it has been forbidden to produce and commerically use polychlorinated biphenyls (PCB) in this country, their stocks and contaminated refuses continue to be a source of danger at present. Hence prevention of environment and food chain contamination is being focused on, along with their monitoring in various commodities. In the poultry operations random contacts of poultry with PCB-containing materials may be expected (paints, plasters, litter). In our experiment we investigated metabolic and immunotoxic effects of low PCB doses on broiler chickens. A hundred and twenty sexed straight-run chicks randomly divided themselves into three departments on deep litter. Cockerels had an ad libitum access to feeds and water, and they were reared under a continuous lighting regime. A feed mix BR-2 (ME 12.8 i.u., crude protein 19.9%) was used as an experimental diet. The experimental groups received a contaminated mix (equal portions of original commercial PCB preparations--Delor 103 and Delor 105 manufactured by the firm Chemko Strázske) at doses of 5 and 50 mg/kg. Chick exposure to PCB lasted from the first to 42nd day of their life. Chick weight, relative organ weight and vitamin A and E levels in liver were determined at the end of the experiment (42 days). The concentrations of cholesterol, triglycerides, proteins, calcium and lysozyme were determined in the blood serum. The concentrations of antibodies to chick repeated immunization with a vaccine against Newcastle disease (AVIPEST) and the blood picture of chicks were also evaluated. Chronical PCB applications in broiler diet resulted in a significant decrease in the weight of broiler chicks at the age of 21 and 28 days (P < 0.01). The weight differences were compensated later on, and the chick weight of the different groups at the age of 42 days was not significantly affected by this treatment. Hepatitis and hydropericarditis were found in affected chicks at their dissection (age of 42 days). Liver weight significantly increased after administration of both PCB doses (P < 0.01), but the relative weight of lymphoreticular organs (thymus, spleen, bursa Fabricii) decreased (P < 0.05). There were serious metabolic disorders in the blood serum after 42-day PCB applications. Cholesterol and triglyceride concentrations (P < 0.01) were significantly increasing (P < 0.01), while the content of serum calcium significantly dropped (28 and 35 days of age). PCB exposed cockerels had the significantly lower titre of antibodies to repeated immunization against Newcastle disease.(ABSTRACT TRUNCATED AT 400 WORDS)

[Clinical effects and morphological changes after administration of low doses of ochratoxin A to broiler chicks]. / Klinické úcinky a morfologické zmeny po nízkych dávkach ochratoxínu A u brojlerových kurciat.

Ochratoxin A (OA) was fed to HYBRO broiler chicks at a relatively low levels of 850 micrograms/kg up age 42 days. The effects of OA on chick development, health state and the patho-morphological lesions in internal organs were investigated in this experiment. The chicks exposed to the relatively low OA levels were observed to lag behind in their growth; this was confirmed by their regular weekly weighing when the lower liveweight in comparison with the control group was recorded from the age of 14 days. A decrease in the liveweight was statistically significant at the age of 21, 28 and 35 days. The patho-anatomic finding was negative. A histological examination of kidneys and liver revealed the pathological lesions typical for ochratoxicosis. The lesions observed included the dystrophy of the tubular epithelial cells (Fig. 1), eosinophil granules in the tubulus lumen (Fig. 3), dystrophic lesions in the glomerules (Fig. 2) and cellulization of the connective tissue of intertubular spaces (Fig. 1). The lesions of liver (Fig. 4) show to allergic responses and defense reactions of the organism to the OA action. On the basis of results it can be concluded that the relatively low ochratoxin levels cause histopathological lesions in the kidneys and liver of chicks, and in this way they can negatively influence their development and performance.

[Long-term administration of the mycotoxin, ochratoxin A in chickens and the residues in the meat and animal feed]. / Dlouhodobý príjem mykotoxinu ochratoxin A u kurat z hlediska reziduí v potravinárských a krmných surovinách.

A feeding trial was performed with chick broilers (cockerels). The feed with an addition of 850 micrograms ochratoxin A (OA) per kg was administered for six weeks. The feeding of the chicks stopped twelve hours before slaughter (in keeping with slaughter technology for chicks). Blood, liver and kidney samples were taken. At the end of trial the level of OA residues in the samples did not exceed 5 micrograms per kg. In other trials the dynamics of OA residues in the blood plasma of chicks was investigated after i.v. implantation at an amount of 2 and 20 micrograms per chick (1.5 kg lw.). An open two-compartment model was used to estimate toxicokinetic parameters. The half-time of elimination (t1/2(beta)) was about 3.3 hours. The high total clearance (CL) of 34.2 ml/min/kg lw. and apparent distribution volume (Vd(area)) of 9.8 l/kg lw. demonstrate rapid distribution to the tissues and rapid OA elimination. The results document that neither at a long-term intake of feed contaminated to the level of 850 micrograms OA per kg will the present hygienic limits of residues for foods be exceeded (5 and 20 micrograms per kg) if the principles of correct slaughter technology are observed. The blood of chicks used as feed is not an important source of OA in this case.

Changes in plasma testosterone, thyroxine and triiodothyronine in relation to sperm production and remex moult in domestic ganders.

Changes in plasma testosterone (T), thyroxine (T4), triiodothyronine (T3), semen output and remex moult were studied in domestic ganders. A bimodal pattern in both plasma T and sperm concentration was observed during the annual cycle. Ganders started to produce semen at the end of January; maximum semen volume (0.32 +/- 0.04 ml) and sperm concentration (148 +/- 38 x 10(3)/mm3) were reached in March and a marked decrease was observed after mid-April, when the moult of the remiges began. Plasma T3 levels peaked in February (9.7 +/- 0.6 nmol.l-1) and this peak coincided with maximum T concentrations (9.8-10.4 nmol.l-1). Elevated levels of T4 were found from late February until mid-April (31.0-33.6 nmol.l-1). Plasma T concentration was low at all stages of remex moult and regrowth. Decreased T4 levels were found in ganders during remex regrowth from the "brush" to half of the full primary growth stage. Higher plasma T4 levels were found before and after this stage of the moult. A reverse pattern was observed for T3 concentrations.

Testosterone concentration in the seminal plasma of cocks.

Testosterone concentrations in the seminal plasma of cocks ranged from 0.46 to 5.05 ng/ml and were substantially lower than in blood plasma. No significant variation was noted in seminal plasma testosterone concentrations during the light phase of the day, whereas the concentration in blood declined over this period. Spermatozoal concentration and seminal testosterone decreased in the third sample of the semen collected sequentially at 3 h intervals. Testosterone concentrations in seminal plasma (1.57 +/- 0.17 ng/ml) and in the semen from the ductus deferens (1.34 +/- 0.24 ng/ml) were not significantly different.

[Sexual development and levels of plasma testosterone in the light type of cockerel]. / Pohlavný vývin a hladiny plazmatického testosterónu u kohútikov l'ahkého typu.

The concentration of testosterone in blood plasma during the ontogenetic development of cockerels was studied in relation to the development of spermatogenic part of gonads. On the basis of the results, sexual development of cockerels can be divided into three stages. The first stage (from hatching to the age of eight to nine weeks) was characterized by a slow increase in gonad weight, by low concentration of plasma testosterone (0.4-2.0 nmol/l) and by the occurrence of spermatogonia in testes. In the course of the second stage (from the age of nine to 16 weeks) a rapid increase in the weight of testes and testosterone concentration was observed. At the end of this stage all phases of spermatogenic cycle were observed in gonads; the testosterone levels averaged to 10 nmol/l. In the course of this stage all cockerels reached sexual maturity; large individual differences in spermatogenesis development were observed. The third stage (16 weeks of age and more) was characterized by an intensive spermatogenesis, further increase in gonad weight and by typical variations of the plasma testosterone levels. The concentration of the circulating testosterone increased before the onset of the final stages of the spermatogenic cycle.

[The relation between the concentration of testosterone in seminal plasma and certain indicators of reproduction in roosters]. / Vztah koncentrácií testosterónu v semennej plazme k niektorým reprodukcným ukazovatel'om kohútov.

Testosterone concentrations in the semen plasma of the cocks of the laying type were analyzed. The levels in semen plasma were substantially lower than in peripheral blood and were found at the interval of 1.58 to 13.30 nmol . 1(-1), the average values amounted to 5.5 nmol . 1(-1). At the repeated samplings of the same animals, considerable variability of hormone levels was observed, which suggested a possibility of the pulsation character of the changes in the androgen also in this biological material. The correlation coefficients between the testosterone levels in semen plasma and ejaculate volume, as well as between the sperm concentration were positive, however, statistically insignificant. The relation between testosterone and the weight of testes was at the significance limit.

[Concentration of plasma testosterone in adult roosters of a low-weight strain]. / Koncentrácie plazmatického testosterónu u dospelých kohútov l'ahkého typu.

The levels of blood-plasma testosterone were studied in the adult light bodied strain cocks. Blood was sampled (1 ml) from the wing vein by means of a heparinized syringe six times within a 24-hour interval. The plasma obtained by centrifugation was kept in a refrigerator at a temperature of --18 degrees C. Testosterone was determined by the radioimmunological method. The testosterone levels were significantly higher (P less than 0.001), 18.8 nmol/l on the average, in the blood samples taken during the dark period of the day (10 o'clock p.m., 2 and 6 o'clock a.m.) than in the samples taken in the light part of the day (8 and 10 o'clock a.m., 2 o'clock p.m.) when the average concentration of the studied hormone was 10.7 nmol/l of plasma. the lowest levels of testosterone were recorded in the morning and the highest values were recorded late in the evening (10 o'clock p.m.). The differences in the levels of the hormone between sampling terms indicate that the testosterone level in adult animals shows diurnal variances. It was found by the study of the concentration of testosterone in the blood plasma of the same individuals within short intervals of time (30-60 min) that testosterone secretion in adult cocks had a pulsatory manner. The evaluation of hormone levels should include not only the diurnal variances but also the pulsatory manner of testosterone secretion.

[Increased hepatic aryl 4-monoxygenase in chickens caused by lipophilic xenobiotics]. / Zvýsená aktivita hepatálnej aryl 4-monooxygenázy u sliepok spôsobená lipofilnými xenobiotikami.

Hens were treated with three types of lipophil xenobiotics - polychlorinated biphenyl (PCB), lindane and hexachlorobenzene (HCB) - to study changes in the levels of microsomal proteins and in the activity of microsomal aryl 4-monooxygenase in liver. The above foreign substances were given in feed at a dose of 50 mg per kg during a fortnight. The level of microsomal proteins in liver increased after seven-day administration of xenobiotics and was always higher in the course of the experiment than in the controls. The activity of the microsomal enzyme (aryl 4-monooxygenase) was significantly higher in treated hens after seven- and 14-day interval, and also seven days after the end of feeding the contaminated feed mixture. Inductive properties were strongest in polychlorinated biphenyl (Delor 103), but lindane and hexachlorobenzene also induced a statistically significant rise, in comparison with the controls. It is shown that the inductive ability of lipophil xenobiotics is stronger in hens than in chicks, which may influence the metabolism of some biologically important substances in poultry organism.

[Induction of hepatic microsomal enzymes in chickens effected by various persistent foreign materials]. / Indukcia mikrozomálnych enzýmov pecene kurciat úcinkom niektorých perzistentných cudzorodých látok.

Changes in the levels of microsomal proteins, in the activity of microsomal aniline hydroxylase, and in the effectivity of Thiopental were studied in chickens given the Czechoslovak-produced type of polychlorinated biphenyls - Delor 103. The increased activity of aniline hydroxylase and the decrease of Thiopental sleeping time in chickens exposed to the action of Delor 103 indicate that this preparation is able to induce liver microsomal enzymes in doses as low as 5 mg per kg of feed. The induction of liver microsomal enzymes appears to be an important factor, able to exercise a direct influence on the biotransformation of various biologically important substances in the organism of chickens.

[Changes in the biological activity of androgens after the exposure of cockerels to lindane]. / Zmeny v biologickej úcinnosti androgénov po expozícii kohútikov lindanu

A biological test was performed to study the changes in the effectiveness of androgens after the administration of different doses of lindane to sexually immature cockerels. Testosterone-propionate and Stenolon were used as reference hormones. The results indicate that the administration of lindane increases the biological effectiveness of testosterone-propionate expressed through the stimulation of the growth of comb. On the other hand, the effect of the insecticide caused a statistically highly significant reduction of androgenic activity when Stenolon was used as a reference preparation. The causes leading to different manifestations of the interactions of lindane with the two hormones tested are analyzed. The paper gives further proofs that the exposure of poultry to relatively low doses of chlorinated insecticides interferes with the biological effectiveness of sex hromones.

[Effect of lindane on the biological effectiveness of estradiol in chickens]. / Vplyv lindanu na biologickú úcinnost estradiolu u kurciat

After exposure of sexually immature chickens to lindan in doses of 2.5 to 25.0 mg kg-1 of feeds, the effect of the insecticide on the biological activity of estradiol was investigated. The changes in the effectiveness of estrogen, expressed by an increase of the mass of the oviduct and of the level of serum calcium, were evaluated by means of comparison of animals exposed to the insecticide with a control group that had been applied only the standard hormone dose. Proofs were obtained for the fact that the application of lindan in the quantity of the mentioned doses for 14 days caused a statistically conclusive depression of the biological effectiveness of estrogens. Compared with the control group, the stimulated mass of the oviduct of animals exposed to the insecticide was smaller by 12.7 to 17.1 p. c. and the average concentration of the serum calcium decreased by 8.0 to 27.6 p. c. The results obtained indicate that the influence of lindan already in relatively low concentrations caused significant changes in the effectiveness of exogenous estrogens.

Distribution of labelled testosterone in Japanese quail using autoradiography of whole body sections.

Auto radiography offers a simple method of giving preliminary information about the metabolism in vivo of steroids. 2. In Japanese quail injected testosterone is metabolised mainly in the gastro-intestinal tract.