The article presents the results of studies on the absorption, distribution and excretion of the antibiotic Poledoxin (the active substance is doxycycline hyclact) from the body of healthy broiler chickens of the Koob-500 cross when taken orally. Studies have established the rapid absorption of doxycycline hyclact from the digestive tract of the chicken into the blood and its entry into the internal organs. The maximum concentration of doxycycline hyclact was detected 2-4 hours after the start of Poledoxin administration, the content of which in the liver was 9,07±0,07 μg/g, in the lungs – 8,39±0,20 μg/g, in the heart – 4,24±0,09 μg/g, in the pectoral muscles – 4,28±0,23 μg/g. In the kidneys, the maximum concentration was found after 12 hours – 7,63±0,38 μg/g. When clinically healthy broiler chickens were fed with Poledoxin solution, the ability to materially cumulate doxycycline hyclact (active ingredient) was not established, since its content in the internal organs and muscles of the bird did not depend on the duration of the drug use. Studies have established the absence of organ affiliation of doxycycline hyclact, because its maximum content, depending on the study period, was recorded in various organs that provide biotransformation and excretion – liver, kidneys, lungs. The cancellation of drinking Poledoxin ensured the rapid elimination of doxycyclin hyclact from the body of broiler chickens and, after 5 days (for 216 hours of the experiment), its content was minimal for the entire study period and amounted to: in the kidneys – 0,15±0,01 μg/g; liver – 0,12±0,01 μg/g; pectoral muscles – 0,05±0,01 μg/g; lungs – 0,04±0,01 μg/g. Only in one sample of the heart, doxycycline hyclact was shown in an amount of 0,01 μg/g. Key words: Poledoxin, doxycycline hyclact, broiler chickens, distribution, accumulation, hatching, bioavailability, pharmacokinetics, excretion.

The results of studies of the effect of the drug "Poledoxin", belonging to the group of tetracycline and the drug "Tilmox 25%", belonging to the group of macrolides, on the biochemical parameters of the serum of broiler chickens cross "Cobb-500". It was found that the drugs "Poledoxin" and "Tilmox 25%", which were used in clinically healthy broiler chickens according to the scheme recommended for the treatment of birds with ornithobacteriosis and mixed infections, had a threshold effect on their body, without changes in clinical and behavioral status and reactions of birds. A study of the protein spectrum of poultry serum showed that under the influence of "Poledoxin" and "Tilmox 25%", develop hypoproteinemia due to a decrease in albumin levels by 10-53% (P≤0.05). In the serum of chickens of the first and second experimental groups, an increase in uric acid content by 11 and 8%, respectively (P≤0.05) was found 2 days after the use of antibiotics, and the maximum value exceeded the control by 21% (P≤0,05), is established in 3 days after the termination of their application. The content of creatinine in the serum of chickens fed antibiotic solutions increased, and after three days was higher than the birds of the control group by 6% (P≤ 0.05). 3 days after discontinuation of "Poledoxin", the content of creatinine in the serum of chickens of the first experimental group was higher than the control rate by 15%; and in second, which used "Tilmox 25%" – by 14% (P≤0.05). The study of mineral metabolism revealed a decrease in the content of inorganic phosphorus in the serum of poultry of the first experimental group by 10-19% (P≤0.05), the second – only a tendency to decrease.

Nowadays ornithobacteriosis is widespread among industrial poultry in Ukraine and the world. The disease leads to significant economic losses. The large variation in the serotypes of the bacteria complicates the treatment of the disease. The study of microscopic changes that occur in organs during ornithobacteriosis will help to better understand the pathogenesis of the disease development. Ornithobacteriosis was diagnosed in clinically sick broiler chickens by bacteriological studies using Maldi Tof mass-spectrometry. As a result of the antibiotic sensitivity test, the pathogen was found to be sensitive to doxycycline, tilmicosin, rifampicin, cefazolin, amoxiclav and benzylpenicillin. Histological studies of internal organs – trachea, lungs, heart, kidneys, liver and spleen – were carried out. It was found that with spontaneous ornithobacteriosis of broiler chickens, the most expressive microscopic changes occur in the respiratory organs – the lungs and trachea and are characterized by a decrease in the lumen of the parabronchials due to edema of their walls and infiltration with lymphocytes, the absence of epithelium on the surface of the parabronchials, narrowing of the air capillaries of the parabronchial complexes, hemorrhages in the parenchyma of the parabronchial complexes, vasodilatation of the lung vessels and overflow of their blood vessels with blood cells, edema around the epithelium trachea, destruction of part of the tracheal mucosa epithelial cells, edema of its submucosa, expansion and overflow of blood vessels of the mucous membrane with blood cells. In the spleen there was a uniform diffuse edema of the parenchyma and a decrease in the number of lymphocytes in the lymphoid follicles; in the kidneys – expansion and overflow of the stroma blood vessels, uneven edema of the glomeruli of one part of the renal corpuscles and destruction of the glomeruli of another, granular degeneration of the convoluted and straight tubules of the kidneys; in the liver – edema, hemorrhage, violation of the hepatic lobules’ structure, expansion of the hepatic veins, granular degeneration of hepatocytes or their destruction; in the heart – edema of the myocardial interstitium, muscle fibers’ granular dystrophy, fragmentation of muscle fibers as a result of their rupture. Histological research of ORT infected chickens will lead to a better understanding the mechanism of pathological changes at the microscopic level, which will facilitate the development of more effective methods of treatment and prevention of the disease.

Recently, the problem of increasing the productivity of farm animals is one of the most important for veterinary medicine. Since the animals “programmed” for maximum productivity by selection turned out to be excessively exposed to anthropogenic and biological negative factors, the result of this is a decrease in their productivity. Conducted toxicological, microbiological, mycological and chromatographic studies of the organic feed additive ˮGreenat“, which includes humic acids. It is promising to study the possibility of using preparations containing humic substances to increase the productivity of farm animals and poultry, to enhance the general nonspecific resistance of the body. Given that peat is the raw material for the manufacture of the additive, toxicity, mycological and microbiological indicators are extremely important. Toxicological studies (bioassays on rabbits and Colpoda steinii culture) proved the absence of toxic substances, as evidenced by the activity of the colpoda infusoria for 10 minutes and 3 hours of the study, and the absence of hyperemia and inflammation on the skin of the rabbit. The number of mold fungi does not exceed the allowable limits of 1.5x102 CFU/g (according to the norm 5.0x104), qualitative studies revealed and identified by mass spectrometry the mold fungi A. alternata; C. cladosporioides, which belong to saprophytes and get into the organic feed additive "Grinat" from the remains of plants during their decomposition. Microscopic fungi Alternaria spp. participate in the decomposition and mineralization of plant residues due to the polygalacturonase enzyme complex, which allows them to attach themselves and exist in various conditions. Cladosporium spp. found outdoors and indoors, in degraded organic debris, produce secondary metabolites such as antibiotics that are inhibitors of B. subtilis, E. coli, and C. albicans. Microbiologically, Maldi Tof mass spectrometry detected Bacillus megaterium, which belongs to soil bacteria, and Staphylococcus hominis, found as a harmless commensal on the skin of humans and animals. Chromatographically confirmed the presence of essential amino acids: leucine (0.120%), valine (0.089%), threonine (0.064%), phenylalanine (0.039%), isoleucine (0.024%), histidine (0.021), methionine (0.011%), lysine (0.05%), tryptophan (0.007%). Accordingly, conditionally replaceable and non-essential amino acids, which can help to avoid a shortage of feed components in animal diets. Key words: Greenate, Colpoda steinii, general toxicity, amino acids, molds, Maldi Tof, Bacillus megaterium, Staphylococcus hominis, A. alternata, C. cladosporioides.

The article presents the results of studies of the intake (oral administration), distribution and excretion of Tilmicosin Phosphate (active ingredient of the Tilmox 25%) from the body of healthy broiler chickens of the KOBB-500 cross. The rapid absorption of Tilmicosin Phosphate from the alimentary tract of the birds and its entry into the internal organs was established. The maximum content of Tilmicosin Phosphate was found in the lungs and liver. Only in 2 hours after the beginning of the Tilmox 25% solution application, which was 17.02 ± 0.24 and 12.78 ± 0.22 μg / g, its content in the kidneys after 26 hours was 8 25 ± 0.19 μg / g, pectoral and cardiac muscles after 52 hours - 6.19 ± 0.28 and 5.23 ± 0.39 μg / g, respectively. Consumption of Tilmox 25% solution by a healthy bird was not accompanied by the accumulation of Tilmicosin Phosphate (material accumulation), since its content in the internal organs and muscles of the bird did not depend on the duration of the drug use. During 96 hours of Tilmox 25% solution consumption by broiler chickens the maximum content of Tilmicosin Phosphate was detected in the lungs, which indicates its tissue tropism. The distribution of Tilmicosin Phosphate in maximum amounts to the lungs ("organ affinity" or "tissue tropism") is important when infectious agents are localization in the lungs of poultry, as well as for the treatment of patients with respiratory diseases of various etiology. The cessation of the use of Tilmox 25% was accompanied by a significant decrease in the content of its active substance, Tilmicosin Phosphate, in the organs under study. Twenty-four hours after the cessation of consumption the tilmox solution (120 hours of the experiment), the content of Tilmicosin Phosphate in the lungs was 1.9 times less, liver – 1.6 times, kidneys – 1.4 times, pectoral muscle - 1.7 times, cardiac muscle – 1.3 times less, compared with indicators on 96 hours of experiment. Five days after the cessation of feeding the tilmox solution to broiler chickens (216 hours of the experiment), the residual amounts of Tilmicosin Phosphate in the organs under study were: in the lungs – 1.20 ± 0.03 μg / g; liver – 1.01 ± 0.02; kidneys - 0.91 ± 0.03 μg / g. The lowest content of Tilmicosin Phosphate, during this period of research, was only in one of the three samples of the heart muscle – 0.02 μg / g, and it was not detected in the pectoral muscle. Key words: Tilmox 25 %, organs, distribution, accumulation, excretion, pharmacokinetics.