Ecotoxicologic relations on a large pig-fattening farm located in a lignite mining area and near and solid-fuel electical power plant]

Major contaminants identified in 1983-1984 on a pig fattening farm with an output of 60,000 pigs per annum, located in a lignite mining area and near a solid fuel power plant, were mercury, cadmium, lead, chromium and aflatoxin B1 (Tab. I, II, III, IV). Feed samples were collected from througs to assess the contamination load at feed uptake. Permissible concentrations of mercury, chromium, cadmium, aflatoxin B1, lead and atrazin in the feed were exceeded in 56, 50, 31, 19, 6 and 6% samples, respectively (Tab. I). Stable dust deposits, in which the contaminants concentrate, (Tab. I) proved to be a suitable material for assessing the type and level of environmental contamination. Permissible concentrations of mercury, cadmium and lead in porcine muscles were exceeded in 65, 51 and 24% samples, respectively (Tab. III). Corresponding values of mercury, cadmium, lead and aflatoxin B1 in the liver were 27, 27, 16 and 3%, respectively (Tab. III) and those of mercury, lead and chromium in kidneys 24, 22 and 5%, respectively (Tab. III). Rather surprisingly, elevated pancreatic concentrations of aflatoxin B1 were found (Tab. IV). Pigs fattened in the contaminated environment (i.e. fed contaminated feed mixtures, inspiring contaminated dust and absorbing percutaneously contaminants form dust deposits on the body surface) showed: 1) Impairment of the genetic apparatus (percentage of aberrant peripheral leucocytes elevated to 6.2%); 2) a certain degree of immunosuppression (concentrations of IgG, IgM and IgA reduced by 16.9, 45.1 and 45.0%, respectively); 3) higher feed consumption per 1 kg weight gain (4 kg) and lower average daily weight gain (0.57 kg); 4) increased incidence of health disorders (dermatitis in 25%, pancreatopathy in 13%, liver dystrophy in 8% and femoral fracture in 6% of the pigs). Unfortunately, the authors were not allowed to analyse ash and solid emissions from the power plant. Therefore the share of the emissions in the overall environmental contamination on the fattening farm could not be quantified. The personnel, working in the contaminated environment for a prolonged period, is endangered most of all by stable dust, being exposed to its mechanical, chemical, allergic and infectious effects (Tab. I). In addition to the chemical contaminants, 21 mould genera and species, six mite species and numerous saprophytic and some pathogenic bacteria were demonstrated in stable dust samples in our earlier experiments. Consumption of meat and organs from pigs fattened in a contaminated environment is associated with the risk of an increased uptake of various contaminants.(ABSTRACT TRUNCATED AT 400 WORDS)     

Ultrastructural study of the hypothalamic region after administration of aurothioglucose in mice]

Aurothioglucose dose of 1 mg g-1 1. w. was applied intraperitoneally to experimental female mice. After 24 hours the animals were decapitated and samples for ultrastructural examination were immediately taken from the region of the hypothalamic ventromedial nucleus. The following findings were obtained from the study of 243 electronograms of 8 experimental animals: 1. dense round particles 0.034 to 0.016 mu in size, representing the gold of aurothioglucose; 2. parenchymatous dystrophy of the mitochondria; 3. peeling off of the individual layers of myelin sheath and the granularity of these layers corresponding to the disintegration of nerve fibres.     

Serum selenium levels in sheep from birth to 90 days of age]

The results of the study of the dynamics of selenium in the blood serum were compared in 31 piglets from birth to the age of 90 days. The analyzed selenium values in the blood serum immediately after birth (0.14--0.20 ppm) provide evidence of the intra-uterine placental passage of selenium. In the period of colostral and milk nutrition, the serum concentrations of selenium showed a statistically insignificant variation, followed by an abrupt drop of the level of the microelement in the weaning period (60th day). The individual values in this period ranged from 0.08 to 0.12 ppm. Towards the end of the study, the level of selenium in the blood serum of the piglets returned to its initial value; this indicates that although the critical period connected with weaning has a transient nature, it should be averted for preventing the occurrence of a selenium-deficit disease; this can be done by adding a supplement of 0.2% solution of sodium selenate or a combined preparation of selenium and vitamin E-Selevit.     

Evaluation of the results of ELISA in the quantitative determination of antibodies against infectious bursitis in poultry]

Specific antibodies were investigated in serums of chicks vaccinated with live vaccine and revaccinated with inactivated vaccine against the infectious bursal disease virus, using three methods. An ELISA technique was used to determine antibody titres at a fourfold serum dilution; the reaction was evaluated visually. The results were compared with the titres of neutralizing antibodies and percentage of samples with precipitin activity (Fig. 1). The average values of neutralizing antibody titres and ELISA titres were found to have an analogical pattern; a decrease in maternal antibodies on the first days of chick life and an increase in the antibodies after vaccination, accompanied by an increase in precipitin activity, were typical in these tests. Using the different ELISA technique, 138 samples of fowl serum were examined (Fig. 2). The high correlation, r = 0.85, was found between the ELISA titres determined by visual reading of the reaction within the fourfold serum dilutions and the absorbance values determined at single serum dilution. Applying a spectrophotometer programme, a scale of antibody quantification was made up pursuant to the intensity of immunoenzymatic reaction. For the purposes of method reproducibility, the evaluation was made within the average values of absorbance of positive serum on the one hand and of negative serum on the other. The span of these values was divided into ten equal parts, designated by degrees 0 to 9. Corresponding degrees of positivity were assigned to the examined samples in dependence on the determined value of absorbance (Fig. 3). The correlation r = 0.61 was found between the ELISA values and the titres of neutralizing antibodies.(ABSTRACT TRUNCATED AT 250 WORDS)     

Regulation of milk intake in young ruminants

We studied the influence of the three main nutritive components of milk - saccharides, fat and amino acids - on milk intake in suckling lambs and on the role of insulin as a key metabolic hormone for the regulation of milk intake. The intake was slowed down after p.o. administration of milk fat (p less than 0.05), after i. v. administration of methionine (p less than 0.001) and after p. o. administration of glucose, lactose (p less than 0.01, p less than 0.001) and sorbitol (p less than 0.001). After i. v. administration of glycerol, lysine, threonine, arginine, glucose, and i. v. and p. o. administration of galactose the intake of milk did not change significantly (p greater than 0.05). The findings indicate that the short-time regulation of milk intake in suckling ruminant animals is not subjected to the specific effect of some of the milk components. Regarding the metabolic effects, the problem concerns the speed of resorption of easily metabolizable sources of energy from the digestive system to the liver and to the whole body. Neutral Zn-insulin administered intraperitoneally at a dose of 4 U X kg-1 increased the milk intake (p less than 0.01, p less than 0.001), in 8 to 22 hours after the administration only when the animals were on the low-fat milk diet (5.9%-11% fat in dry matter). We assume that the long-range hyperphagy can be related mainly with the fast metabolizing of energy-rich substances (glucose) into the body stores (glycogen, fat) accompanied by subsequent hormonal changes.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of high doses of aflatoxin on the pig]

In two experiments, 18 pigs were given feed contaminated with aflatoxin which had been prepared by the extraction of the cultures of toxinogenic strains of the fungus Aspergillus flavus. After the ingestion of aflatoxin (AFB1) at a dose of 5.4 to 10.5 mg per kg of live weight, the pigs showed symptoms of peracute aflatoxicosis and died within 12--20 hours. After ingestion of AFB1 at a dose of 1.4 or 3.1 mg per kg live weight, the pigs suffered from acute aflatoxicosis and died within 3 to 26 days from the administration of the contaminated feed. In the cases of these experimental aflatoxicoses, clinical symptoms, haematological and biochemical changes in the blood and the patho-anatomical and histological findings in the swine organism were described.