Liniichuk N. Sanitary and Hygienic Assessment of Broiler Chickens by Using Enrofloxacin

For the first time in Ukraine, the suitability of the method for quantification of enrofloxacin in muscles tissues, blood and litter of broiler chickens has been assessed in accordance with the European Commission Decision 657/2002/EC. The results of the state monitoring of antibacterial substances application in Ukraine during the years 2013–2019 have been analyzed. Two positive results pertaining to hen eggs containing residual enrofloxacin have been revealed within the study period. Residual content of enrofloxacin, which did not exceed the MRL was also found in 74 % of the studied samples of broiler chicken meat. Enrofloxacin administered in therapeutic concentration orally with drinking water to broiler chickens does not affect their clinical condition. No effect of enrofloxacin on live weight gain of broiler chickens has been found in the experimental groups, however, an increase in weight of chickens slaughtered on the 14th day after cessation of the drug administration has been revealed. According to chemical indices, the meat of broiler chickens of the experimental group was fresh. However, reactions with copper sulphate, ammonia and ammonium salts demonstrated that meat of broiler chickens of the experimental group slaughtered on the 14th day after cessation of enrofloxacin administration was of dubious freshness on the 4th day of its storage. The highest concentration of enrofloxacin in tissues of broiler chickens exposed to enrofloxacin treatment was found in skin, wings and thighs. High levels of enrofloxacin in blood and chicken manure were being detected throughout the study period. The results of toxicological and biological assessment showed that muscles and skin of broiler chickens containing high levels of enrofloxacin were of weak toxicity and of low biological value. However, according to microbiological indices the meat complies with requirements of the regulations that are currently in force in Ukraine. Treatment of broiler chickens with enrofloxacin did not affect the level and species composition of the microflora in poultry muscles. The histological examinations revealed microscopic changes in all muscles of broiler chickens of the experimental group.