БеЗоПасностЬ стерляди, выращенной в условияХ уЗв наумова валентина васильевна, кандидат сельскохозяйственных наук, заведующая кафедрой частной зоотехнии, технологии животноводства и аквакультуры кирьянов дмитрий анатольевич, кандидат сельскохозяйственных наук, доцент кафедры частной зоотехнии, технологии животноводства и аквакультуры свешникова елена васильевна, кандидат биологических наук, доцент кафедры частной зоотехнии, технологии животноводства и аквакультуры

The paper gives the analysis of the influence of water temperature on the structure of metabolic energy in carp and silver carp of different age groups. The thermophilic species of carp and spotted silver carp cultivated in the polyculture with natural nutritive base served as the material for a research conducted in a hatchery “Individual Enterprise of Alekseeva M. V.” in Kuzovatovsky district of the Ulyanovsk region. Analysis of fish metabolic energy was made using the mean of live weight of yearlings and two-year-old species of carp and silver carp. As a result, there have been obtained the values of the metabolic energy in fingerlings and two-year-old species of carp and silver carp at different ranges of water temperature. Metabolism in carp and silver carp species being representatives of thermophilic fish is most effective at temperatures within +18-+30°С. The study showed that a decrease in water temperature by 5°C (from 20 to 15°C) causes a decrease in food activity, the daily feed intake of yearlings and two-year-old species of carp and silver carp decreased by 35-40%. Expense for the basal metabolism and growth did not change. Metabolic energy was used by 10.8-13,3.0 kJ less. Also, yearlings and two-year-old species of carp and silver carp spent less energy on motion activity than in the warmer water. Thus, under a decrease in the water temperature in the pond the costs of maintaining thermal homeostasis in fish increased, while the costs of basal metabolism, on the contrary, decreased. Situation is quite different when the water is warmed up.

The article studies the safety of sterlet grown in recirculating aquaculture systems. The research was carried out in the research and training laboratory on reproduction and cultivation of sturgeon species of the Department of private animal husbandry, livestock and aquaculture technology of Ulyanovsk State Agrarian University named after P. A. Stolypin and Simbirsk Veterinary Reference Center in Ulyanovsk. The material for the study was chosen sterlet grown in recirculating aquaculture systems. In the recirculating aquaculture system food components and metabolites accumulate, which may affect fish health and quality and safety of fish meat. In the course of studies it has been found that hydrochemical parameters of water taken from the breeding tanks comply with the standards: ammonia content as the main indicator affecting the growth and development of fish did not exceed 0.05 mg/dm3. This is due to compliance with fish stocking density, optimum temperature (18-22°C) and pH level (7.3). The content of sulfates was also within the norm -52.78 mg/dm3. Mass fraction of chlorides was 14.82 mg/dm3 and of nitrites - 0.052 mg/dm3, which is 20 and 50 times lower than the standard values. The fish was studied for organoleptic, microbiological parameters, as well as for the content of toxic elements. Organoleptic characteristics (appearance, fish condition, smell, color of eyes and gills) fully meet the requirements of GOST 7631-2008 “Fish, non-fish objects and their products. Methods for determination of organoleptic and physical parameters”; such toxic elements as cadmium (Cd), arsenic (As), mercury (Hg) and lead (Pb) were detected in fish samples, but their content was negligible and did not exceed the maximum permissible concentrations. The presence of genetically modified organisms, pathogens, BGB (coliforms), Listeria, nematodes were not detected. According to the study results, sterlet grown in the recirculating aquaculture conditions of the research laboratory for reproduction and breeding of sturgeon species of the Department of private zootechny, technology of animal husbandry and aquaculture of Ulyanovsk State Agrarian University can be considered completely safe in terms of microbiological, parasitological and chemical indicators.