[Content of chemical elements in the liquid manure of swine at a treatment plant using biological purification]. / Sudurzhanie na khimichni elementi v techen tor ot svine v prechistvatelna stantsiia s biologichno prechistvane.

An atom absorption spectrophotometer was used to study 13 chemical elements in samples taken at the entrance of the purification station, at the mechanical step exit, at the biostep exist, and at the laguna exit as well as following treatment of the solid fraction in open surface purification and drying plots. It was found that part of the biogenic chemical elements remained in the liquid fraction after purification and were hazardous in terms of eutrophication of the water receptacle. A technology was worked out to treat the solid fraction, however, it did not provide for preserving the biogenic chemical elements. This lowered the qualities of the fraction in enriching the soil.

[Microbial decontamination by aerobic purification of liquid manure from swine-breeding farm complexes]. / Mikrobna dekontaminatsiia pri aerobno prechistvane na techen tor ot svinekompleksi.

Studied was the microbial decontamination of swine mature with the employment of a laboratory model of an aerobic lagoon as well as in a purification station, having a mechanical step, two biologic steps, and a facultative lagoon. It was found under modelled conditions that a substantial decontaminating effect was produced with regard to coli bacteria and Salmonella organisms. The effect was less with regard to the microbial count. The studies carried out in stations showed the effectiveness of the individual steps in reducing the microbial content of manure.

[Microbial contamination of the air in the commercial production of poultry meat]. / Mikrobno zamursiavane na vuzdukha pri promishleno proizvodstvo na ptiche meso.

Microbiologic studies were carried out on industrial premises for the raising of broiler birds on deep litter over a flooring area of 2000 m2 at mechanical ventilation of negative pressure. The microbial count was established through culturing in meat-and-peptone agar regarding the presence of coli bacteria, microscopic fungi, hemolytic cocci and Salmonellae in the air. Studies were also performed to establish the contamination of the atmospheric air at a distance of 10 m surrounding the premises, of the litter as well as of the feed and the soil in immediate proximity to the buildings. It was found that as a result of raising the 'biologic loading' of the ecotope by 60 per cent the microbial contamination of the air in the industrial buildings rose. The basic sources of contamination were the deep litter, the atmospheric air introduced by the ventilation system, the soil, and the feed.

[Possibilities for decontaminating the air in commercial poultry breeding]. / Vuzmozhnosti za obezzaraziavane na vuzdukha pri promishleno otglezhdane na ptitsi.

Experiments were carried out in bacteriologic and fumigation chambers to restrict the microbial contamination of the air on industrial premises via artificial ionization of the air or aerosol spraying of water and disinfectants. It was shown that the differential application of artificial ionization of air was appropriate in that the demands of the technology aiming at maximum stimulation of productivity were met as suggested by the authors. Besides, this technology provided for the treatment of air of high concentration of air ions coming in the outer space at the rate of 150-200 thou per cu. cm3 from production premises. It is expedient to practise the aerosol dispersion of water in the production buildings for the cell raising of birds as an opportunity for limiting the microbial contamination of air and the lowering of the unfavourable effect of high summer temperatures. It was found that in this country's conditions of industrial poultry raising most rational was the use of lactic acid at the rate of 0.004 per cu. m air, used as a 0.002 percent solution.

[Microbial contamination of the air in the housing of laying hens]. / Mikrobno zamursiavane na vuzdukha v pomeshteniia za kokoshki nosachki.

Studied were buildings of one and the same design, sizing 92/12/3.5 m. Building A of mechanical ventilation through negative pressure housed 9,000 layers of the White Leghorn breed, and building B of ventilation with equated pressure, providing the same debit per kg biomass, housed 20,000 layers. The air in the buildings, in the close surrounding as well as the feed and soil were investigated with regard to the total counts of organisms as cultured in meat and peptone agar and with regard to the individual counts of coli bacteria, microscopic fungi and hemolytic cocci, and Salmonellae. It was found that the microbial contamination of air on the productional premises and of atmospheric air closely surrounding the buildings, was higher in building A. There were differences in the microflora of the air at the level of the individual stories in building B. The differences in the microbial contamination of air between the two buildings was the result of reconstructions concerning the ventilation system as well as of making it more effective.

[Microbial content of the air in poultry houses]. / Mikrobno sudurzhanie na vuzdukha v pticharnitsi.

The industrial animal-breeding complex is characterized as an ecotechnical system the function of which is determined by the action of antropogenic factors. It has been demonstrated that up to now the stress of antropogenic activity has been laid on the optimization of the abiotic factors. The control and optimization of the biotic factors has constituted a problem for industrial poultry breeding, especially important being the microbial content of air. Investigations have shown that with the industrial raising of birds air microbism has assumed the importance of a factor that lowers the effectiveness of the technologies applied. The factors have been discovered that govern the extent of microbial contamination of air. Results of experiments in productional poultry houses and climatic chambers have led to the offer of measures aimed at limiting the microbial contamination of air in the industrial raising of birds.

[Poultry meat production with varying densities in raising the broilers]. / Vurkhu proizvodstvoto na ptiche meso pri razlichna gustota na otglezhdane na broilerite.

Tests were carried out at two densities of raising the broilers on productional premises--16.6 and 23.6 per 1 m2 of flooring. Both the prophylactic programme and the conditions of tending and feeding were one and the same on the premises used. Each one of these was supplied with a cell in which birds were kept at the same density value as that on the other premise. Thus, four groups were formed in all: I--broilers kept at the rate of 16.6 per sq. m, II--broilers raised on the premise at 23.6/m2, III--broilers kept in a cell at 16.6 on the same premise where the other birds were kept at 23.6, and IV--broilers kept at 23.6 per sq. m. on the premise where the rate concerning the other birds was 16.6. The basic integral indices of the production effectiveness as well as the bioconversion of the dietary amino acids were followed up. It was found that during the transitional period the lower productional results with the broilers raised at higher densities were due to the action of biotic factors, and, more specifically, to the changes in the homotypical reactions that were the result of the higher density of raising. In the summer season the pesimal effect produced was a complex one, including not only the biotic factors but also the unfavourable action of the temperature and humidity regime.

[Evaluation of abiotic ecological factors and their dynamics at various densities in raising broilers]. / Pretsenka na niakoi abiotichni ekologichni faktori i tiakhnata dinamika pri razlichna gustota na otglezhdane na broileri.

Three productional experiments were carried out in which the broilers were kept on unified premises under one and the same technology, but at various densities of raising: 14.4 and 23.4/sq. m., and 16.6 and 23.6/sq. m. with the second and third experiment. The dynamic, light intensity, and content of toxic gases along with the homogenization of air in the birds' vital zone were followed up. Differences were established which were defined by the higher density of raising, and which, acting as a constellation on the organism might lower the effectiveness of the technologies employed.

[Effect of artificial air ionization on broilers]. / Vliianie na izkustvenata ionizatsiia na vudukha vurkhu broileri.

Tested was the artificial ionization of the air in climatic chambers in attempts to maintain the abiotic ecologic factors within the parameters required by the industrial technology of raising. The feeding and raising of birds were carried in accordance with the provisions of the Bulgarian State Standard requirements. The experiments were carried out with day-old chick broilers divided into two equated groups. All parameters of the production milieu in which the groups were kept were unified with the exception of the ionization of air. The latter was effected following the pattern of a special programme worked out by the authors' team, providing for various exposures and concentrations of the ions in dependence on the age of birds. The investigation of the abiotic and biotic factors acting in the two chambers has revealed a reliable drop of the microbial contamination of the air under the effect of artificial ionization. It has been found that air ionization applied according to the tested programme stimulates the life processes in the body of broilers as evidenced by the anabolic processes with proteins, the higher vitamin A and E level in the liver, and the activation of haemopoiesis. As the result of the reduced microbial contamination of the air and the biologic action of the air ions on the body of the birds in the test group higher weight was obtained (by 19 g) as against the controls at a lower feed intake per unit of gain, with higher indices of the poultry meat. The chemical investigation of such meat of the test group birds has revealed higher protein and essential amino acid content.

[Ecological monitoring in agro-ecological systems]. / Ekologichen monitoring v agroekologichnite sistemi.

The fundamental principles of the ecologic monitoring in the antropogenic ecosystems are dealt with. Analyzed are the structure and function of the agroecologic systems, and, on the basis of the particular aspects established a concept is developed of the ecologic control at autoecologic and biocoenologic level. An analysis is likewise made of the ecologic sequelae resulting from the chemical war launched by the American aggressors in Vietnam and the specific trends therefrom in the substantiation of the ecologic monitoring. Stated is the necessity of profound investigations to establish the bioaccumulation of dioxine, a poisonous agent which was contained in herbicides and defoliants used in the war, and which was distinguished by exclusively high toxicity, producing teratogenic and cancerogenic effects and possessing high resistance in the environment.

[Scientific and applied aspects of veterinary ecological control over the industrial technologies in animal husbandry]. / Nauchni i prilozhni aspekti na veterinarno-ekologichniia kontrol na promisklenite tekhnologii v zhivotnovudstvoto.

In connection with the transformation of animal breeding and putting it on an industrial base ecologization becomes a strategic trend in this branch of national economy too. Ecologization of industrial stock breeding is associated with the solution of two basic groups of problems: --autoecologic. Measures to optimize the abiotic and biotic ecologic factors in view of the maximum and paying substantiation of the genetic potential of productivity of breeds on the industrial complexes. --biocenologic. Developments that lead to the limitation of contamination of the biosphere with waste products, reducing the lines of the technologic processes on the animal breeding complexes. The characteristic features on the animal breeding complexes are referred to as an artificial ecosystem: limited number of populations and reduced componency, leading role of the antropogenic factors, incomplete turnover and intensive use of substance and energy 'taken' from other natural ecosystems, and necessity of energy input. On such base an evaluation is made of the technologic designs and the need is stated to optimize all ecologic factors. Good results are stated with the optimization of the electric properties of the air. A reassessment is made of the existing technologic designs concerning the disposal of manure. Motivation is the necessity of producing biogas from FYM obtained in raising animals and birds without litter.

[Effect of fluorescent lighting on the growth of broiler chickens]. / Vliianie na luminestsentnata svetlina pri otglezhdane na pileta broileri.

The effect was followed up of green luminiscent light on the growth rate of broiler chickens. The experiments were carried out in a climatic chambers of the Zootron type with a total of 400 day-old chicks kept continuously under such light, which had permanent intensity. In one of the chambers the light was produced by means of a red hot wire, and in the other--through green illumination devices. Within the experimental period of 56 days the chicks were studied in terms of their hematologic and biochemical blood composition (hematocrit, erythrocyte count, total serum protein, liver glycogen, muscle glycogen, carotene, A and E vitamins). Investigated were also the blood sugar and lactic acid levels, and the activity of aldolase, glucose-6-phosphate, succindehydrogenase. It was found that green luminescent light influenced positively the weight gain (3.5%) at lower feed intake as against broilers raised under ordinary light of the same intensity. Certain changes were observed also with regard to the hematological and biochemical indices of the blood of birds belonging to the two groups.