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Biomedical subjects

G Petkov

Publications and source records attributed to G Petkov.

At least 37 records · Page 2Linked to original sources
PubMed1978

[Changes in the biochemical and morphological indices of broiler chickens depending on the temperature and humidity conditions].

A varying temperature and humidity regime was tested on a total of 200 hybrid birds (White Plymouth Rock x Cornish crosses). Investigated were some indices of the carbohydrate metabolism and the deposition of vitamins in the organism as well as the effect of the temperature and humidity regime on the growth and development of broilers. It was established that the content of glycogen in the liver and the muscles in birds raised first at 32 degree C and relative air humidity of 65--70 per cent was higher than in birds raised at 36 degree C and relative air humidity of 45--50 per cent. Besides, these observations were coupled with some changes in the content of blood sugar and the amount of A and E vitamins in the liver. The body weight of the test broilers by the end of the experiment was 30 grams higher than that of the control group broilers.

Age Factors↗
PubMed1977

A test tube method for quantitation of hemoglobin A2 using DE 52 cellulose.

A test tube method for quantitation of Hb A2 which is an adaption of the microcolumn chromatographic method is described. The method uses microangular DEAE cellulose (DE 52, microgranular and preswollen, Whatman Inc.) equilibrated with a 0.2 M glycine-0.1% KCN solution, pH 7.25. Hemoglobin A and F become bound to the resin while Hb A2 is in supernatant fraction allowing its quantitation. The method is simple, rapid, inexpensive and accurate, and allows one technician to determine the level of Hb A2 in at least 50 samples a day. The method can be used with whole blood, hemolysates and blood collected on filter paper.

Buffers↗
PubMed1977

[Applicability of methods for determining air velocity in livestock buildings].

Comparative studies were carried out on the applicability of the katathermometers, mechanical anemometers, and the thermoelectric anemometer type TEA-4, devised by the authors and introduced into practice, for determining the velocity of air in livestock buildings. TEA-4 proved more perspective for measurements in animal breedings as it makes possible a continuous automatic control on air velocity. This, in turn, renders it feasible to follow up the day-and-night and the seasonal dynamics of this microclimate factors. By preciseness and exploitation dependability TEA-4 has proved superior to katathermometers and mechanical anemometers. Its adoption into practice has made it possible to shorten the time of measurement.

Animals↗
PubMed1977

[Effect of the lighting intensity on the raising of broiler turkey poults].

Experiments were carried out with turkey poults of the Ten 30 breed with the purpose to establish the changes in some hematologic and biochemical indices that had taken place under the influence of illumination intensity. It was found that the light regime influenced hemopoiesis as well as the intensity of metabolism. Both the hemoglobin content and the erythrocyte count were higher at illumination of higher intensity. The amount of the blood serum total protein and the vitamin A content of the liver under lower light intensity proved higher by the end of the experiments than in the controls. The weight of poults at lower intensity of light was 5--6 per cent higher, and the intake of forage per kilogram of weight gain was 150 g lower than with poults raiseatd higher intensity of illumination.

Animal Husbandry↗
PubMed1977

[Veterinary health examination of the microclimate of the cow complex in the Vidin district].

Studied was the dynamics of the microclimate at the cow complexes in the district of Vidin, where cows are raised of the Dutch Black Pied, Bulgarian Simmental, and Bulgarian Red cattle breeds. The temperature and relative humidity dynamics of the air was followed up as well as the values of ammonia gas and carbon dioxide, the microbial contamination, the coefficient of natural illumination, and the level of noise. The effectiveness of the ventilation system was assessed by direct and indirect criteria as suggested by the authors. The veterinary and sanitary evaluation by individual elements of the microclimate is carried out on the basis of normative documents in the People's Republic of Bulgaria, USSR, and GDR.

Air↗
PubMed1977

[Osmotic resistance of erythrocytes as a screening method in detecting heterozygotes in beta-thalassemia].

Osmotic fragility of red blood cells in three different buffered solutions, i.e. 0,32%, 0,36% saline and 0,40% Tyrode solution was studied as a screening test for the detection of beta-thalassemia trait. 90 genetically designated beta-thalassemia heterozygotes were studied for the screening tests. In addition 514 school children and 161 patients suffering from anemia of different etiology were also examined for the osmotic fragility screening. The results of the studies indicated that the one tube method screening test with 0.36% buffered saline solution was the appropriate solution in screening for beta-thalassemia trait since the solution was able to detect 99 to 100% of the carriers. However, about 15% of normal individuals were also found to give a false positive for the 0.36% saline screening test. It is recommended that 0.36% buffered saline solution be used as a first screening test for the detection of beta-thalassemia trait since it is simple, rapid, cheap and applicable. Those who are positive with this test are required to be completely studied in hematology for the final diagnosis of either beta-thalassemia trait or other hematologic disorders.

Adolescent↗
PubMed1976

[Effect of high temperatures in the housing on some indices of carbohydrate metabolism in layers].

Experiments were carried out with a total of 60 layers of the White Plymouth Rock breed at the age of one year, acclimiatized to a temperature of 15 degrees C and relative humidity of 60 per cent. The following temperature and moisture regimes were tested: I--20 degrees C and 70 per cent; II--24 degrees C and 70 per cent; III--28 degrees C and 50 per cent; and IV--33 degrees C and 50 per cent. The birds of the control group were raised at 15 degrees C and relative moisture capacity of the air of 60-70 per cent. At the 24th hour and by the end of the seventh 24-hour period temperature vales of more than 28 degrees C led to dependable activization of the glucose-6-phosphatase enzyme in the liver and lower concentration of blood glucose and liver glycogen.

Animals↗
PubMed1975

[Contamination of the air with microorganisms at various distances from the poultry house].

Experiments were carried out to establish the microbial contamination of air (including moulds) at various distances from the buildings for raising birds. Results showed that the presence of organisms in the outer air is directly dependent on the microbial contamination of the air in the poultry houses. It was found that the distances between the buildings are too short and the air driven into the premises is of a high bacterial count. Comparative investigations have revealed that the contamination of the air out of the buildings is likewise dependent on the technologic design of the ventilation system. It is concluded that the low contamination of outdoor air is substantiated by an effective system of forced ventilation on the premises coupled with measures lowering the microbial count indoors.

Air Microbiology↗
PubMed1975

[Efficacy of aerosol disinfection with lactic acid and its effect on the body of poultry].

Comparative studies were carried out to establish the efficacy of lactic acid as a disinfection means. The following pattern was observed in employing the agent: a 20 per cent conc. of the acid at the rate of 20 cu. cm per cubic meter is dispersed three times as an aerosol (at 8, 12, and 6 oclock) in the course of twenty minutes. It was found that the microbial contamination of the air drops three to four times. More pronounced is the bactericidal effect on the coliforms and moulds. The birds of the group treated with lactic acid gain 30 g more per day up to the end of the fattening period. Dependable is the higher serum level of protein as well as the higher protein content of the liver and heart musculature and of the essential amino acid tryptophane in the blood serum and liver of the test birds. Higher was also the glycogen content of the liver of the test group broilers.

Aerosols↗
PubMed1975

[Comparative study of microbial and mold pollution of the air in locations for poultry-keeping in various technologies].

Experiments were carried out to establish the microbial and mold contamination of the air on premises where birds were raised following varying patterns of tending and feeding. It was found that on premises for layers, raised in cages, the microbial contamination of the air was 2-3 times lower. The results obtained showed that the main source of air contamination in places where birds are kept is the litter (the other alternative being the floor type of raising). Differences were established in the egg laying, on the one hand, and the forage intake per 'market' egg, on the other, comparing the two types of raising. As all other factors of microclimate were within the normal range of zoohygiene standards, the basic factor which was incriminated to affect both productivity and forage intake per egg was the amount of the microbial flora of the air. Studies have shown that the number of birds per unit of area is an important factor determining the microbial contamination of the air and the health condition of birds.

Air Microbiology↗
PubMed1975

[The effect of microbial contemination of the air on metabolic indices in broiler chickens].

Trials were carried out with two groups of birds, White Plymouth times Cornish crosses. A third, control group of birds was also involved in the experiments, reared by the same technology. The only difference consisted in that the air in the premise of the test birds had a lower microbial content which, during the experiments was 2 to 5 times lower than that in the air of the controls. It was found that under the effect of the higher microbial content the blood serum protein drops like the protein content of the liver and heart musculature, the content of free amino acids rises, the amount of triptophane lowers, and the activity of GOT and GPT is enhanced. The birds of the control group show higher enzyme activity so far as the glucose-6-phosphatase of the liver is concerned, lower glycogen content of the liver, and lower blood concentration of glucose. By the end of the trials the broilers of the control group were 50 gr less heavy than the lest birds.

Age Factors↗