TILMICOSIN INTAKE AND DISTRIBUTION IN THE BODY OF BROILER CHICKENS WITH ORNITHOBACTERIOSIS

One of the main indicators that determine the effectiveness of the antibiotic in the body is its ability to penetrate and accumulate in high concentrations at the sites of the pathological process. The article presents the results of studies of the intake, distribution, and excretion of tilmicosin phosphate – the active substance of the antibiotic Tilmox 25% from the body of broiler chickens (Cobb-500 cross) with ornithobacteriosis. It was found that in 24 hours after the start of the feeding Tilmox 25% solution to broiler chickens with ornithobacteriosis, most tilmicosin phosphate was contained in the lungs, while in the liver less than 1.6 times, kidneys – 3.0 times, heart muscle – 3.4 times, pectoral muscles – 3.5 times than in the lungs. After 48 and 72 hours, the tilmicosin content increased in all studied organs but the paƩern of its distribution was the same as after 24 hours. Tilmicosin phosphate levels in the lungs exceeded the values in the liver, kidneys, heart, and pectoral muscles by 1.8 times, 2.7, 2.9, and 3.9 times, respectively, at 72 hours of the experiment. At 96 hours, tilmicosin levels were highest in the pectoral muscles, kidneys, liver, and lungs, and only slightly less in the heart than in previous research periods. The obtained results testify to the organ affiliation of tilmicosin phosphate to the lung tissues in broiler chickens with ornithobacteriosis. In a day (120 hours of the experiment) after discontinuation of Tilmox 25%, the content of tilmicosin phosphate in the lungs, liver, kidneys, heart, and pectoral muscles of broiler chickens was 53%, 50, 57, 68, and 34%, respectively, in comparison with values after 96 hours. The Ornithobacterium rhinotracheale sensitivity to tilmicosin and its distribution in maximum amounts in the lungs of broiler chickens with ornithobacteriosis provided a therapeutic effect, which was confirmed by microscopic studies. Studies on the pharmacokinetic properties of tilmicosin have been performed mainly in healthy birds. Therefore, the optimization of treatment regimens of already known antibiotics, which will be based on the study of pharmacokinetic and pharmacodynamic properties not only on clinically healthy but also on diseased organisms is a relevant and important issue in the field of veterinary pharmacology