The production of ecologically clean poultry meat with high biological value to meet the needs of public demand is the primary goal of the poultry industry. Poultry meat is a good product for a healthy human diet due to its nutritional, dietary, and sensory properties, economic availability, and quick cooking. At the same time, using the latest, effective symbiotic and biocidal drugs to increase the productivity of poultry requires more in-depth research and evaluation of their impact on the final product. Based on the analysis of the results obtained by us, it has been proven that the use of the complex of symbiotic drugs “Biomagn” and “Biozapin” and in combination with the biocidal agents “Diolaid” and “Biolaid” to broiler chickens of the Cobb 500 cross throughout the entire breeding cycle allows obtaining high-quality and safe poultry products (chicken meat), with improved quality indicators and higher biological value. An increase in the protein content in the muscles of experimental groups of birds and a decrease in moisture in them was established, which is a consequence of an increase in dry matter content in this tissue. As a result, in the muscles of broiler chickens of the II research group, an increase in energy value was recorded to a greater extent and markedly, along with an increase in the content of essential bioelements (Calcium, Ferrum, Copper, Cobalt, and Selenium (Р ≤ 0.05)) and the content of vitamins A and B1, which indicates a higher biological (nutritional) value of poultry meat compared to such indicators in poultry I of the experimental and control groups. When determining the safety indicators of the chicken meat of the research groups, it was established that there were no residual amounts of veterinary drugs, pesticides, and aflatoxin B1, and the regulated indicators of toxic elements did not exceed the PAI specified in the regulatory documents. Therefore, the proposed complex of drugs in the scheme of the growing cycle of broiler chickens does not hurt the quality and safety of the obtained products (chicken meat). On the contrary, according to sensory and organoleptic studies, higher organoleptic qualities of the muscle samples of chickens of the I and II experimental groups were proven under the conditions of the use of a complex of symbiotic and biocidal drugs: the values of the highest overall score for tasting the meat broth are higher (Р ≤ 0.05) compared with the indicator in the control group.

The paper presents the results of monitoring of compound feeds for different types of chickens for the period 2017–2021 by the indicators of the content of vitamins (A, E, B2) and trace elements (Zn, Cu, Se). Vitamin A content did not show significant deviations from the norm in compound feeds for productive chickens and for reproductive meat poultry, and in compound feeds for reproductive egg hens, samples with low vitamin A content (5.7%) were found. By the content of vitamin E in compound feeds for commercial chickens, the percentage of samples with reduced content was 75.2%, in compound feeds for reproductive egg hens — 63.9%, and in compound feeds for reproductive meat hens — 12.7%. By the content of vitamin B2 in compound feeds for reproductive egg chickens, samples with reduced content of vitamin B2 were not observed, while in compound feeds for reproductive meat chickens, reduction of vitamin B2 was found in 4.0% of samples, and in compound feeds for commercial laying hens in 5.1%. The average zinc content in compound feeds for productive laying hens and reproductive egg and meat hens was within normal limits, but reduced zinc levels were observed in 11.0, 2.5, and 17.3% of samples, and above the MAL — in 11.1, 16.9, and 47.1% of the samples, respectively. The average content of copper in compound feeds for commercial laying hens and reproductive egg and meat hens was within the norm, but the reduced level of the element was registered in 1.4, 0.0, and 18.0% of samples, and above the MAL — in 1.4, 8.3, and 16.9% of samples, respectively. The average content of selenium in compound feeds for commercial laying hens and reproductive egg and meat hens was within the norm, but the reduced level of the element was registered in 52.8, 29.3, and 26.8% of samples, the exceeding of the maximum allowable level was not detected

The prohibition of using antibiotics with growth-stimulating properties in the European Union led to the search for new, safer, more effective, and cheaper feed additives. One of these substances was rare earth elements (REE, atomic numbers 57–71) due to their low toxicity and protective and antioxidant properties. At the same time, higher efficiency of organic forms of REE was noted. Thanks to this, it is possible to assume their even more pronounced effect in nano-sized form as feed additives and the need to conduct research in this direction. Therefore, this work aims to study the metabolic parameters of the blood in rats under long-term oral administration of nanoparticles of one of the representatives of rare earth elements – gadolinium orthovanadate (NP GdVO4:Eu3+) under food stress. Experimental samples of gadolinium orthovanadate nanoparticles activated by Europium (spindle-shaped geometry; size 8×25 nm; initial concentration 1.0 g/dm3) were used in work. Experimental studies on rats were carried out based on the vivarium of the NSC “IEKVM”. The object of research was 140 mature male Wistar rats with an initial weight of 180–200 g. Four groups of animals, 35 rats each, were formed according to the principle of analogs. During the experiment, animals of the control group received drinking water without additives; rats of the І experimental group were given a solution of NP GdVO4:Eu3+ at a dose of 0.2 mg/dm3 (≈ 0.03 mg/kg of body weight); II research group – at a dose of 1.0 mg/dm3 (≈ 0.15 mg/kg of body weight) and rats of III research group – at a dose of 2.0 mg/dm3 (≈ 0.30 mg/kg of body weight). Drinking was carried out for 56 days, then it was completed, and the rats were observed for another 14 days. A nutritionally unbalanced diet was used as a stress factor. Taking into account the results of biochemical studies, the adaptogenic effect of NP GdVO4:Eu3+ in the range of doses of 0.2–1.0 mg/dm3 of drinking water (≈ 0.03–0.15 mg/kg of body weight) on the body of white rats was established under conditions of food stress with optimal duration of action – 28–42 days. Under the conditions of administration at a dose of 2.0 mg/dm3 of drinking water (≈ 0.30 mg/kg of body weight), a hepatic(cyto-)toxic effect of nanoparticles was detected, which was accompanied by an irreversible decrease in the structural indicators of lipid metabolism, the consumption of antioxidant resources and the induction of intensity processes of lipid peroxidation against the background of alanine aminotransferase hyperenzymemia.

Виходячи із доведених протекторних властивостей наночастинок ортованадату лантану, активованого Європієм (NP LaVO4:Eu3+), можливим напрямом їх застосування є використання у якості кормової добавки, оскільки неорганічні (оксиди, хлориди, нітрати) та органічні (цитрати, кормові дріжджі, збагачені Лантаном) форми Лантану вже застосовуються у світовому тваринництві, позитивно впливаючи на ростові якості свиней і курчат-бройлерів, яєчну продуктивність курей-несучок, покращують добовий приріст і виробництво молока великої рогатої худоби, перетравність поживних речовин раціону овець. Проте ефективність кормової добавки має на увазі тривале введення до організму тварин та повинна підтверджуватися покращенням стану організму в умовах стресового фактора. Тому метою даної роботи було дослідження стану метаболічних показників крові щурів за субхронічного перорального надходження наночастинок ортованадату лантану на фоні кормового стресу. У роботі використовували дослідні зразки NP LaVO4:Eu3+ (стрижнеподібна геометрія; розмір 8×80 нм; вихідна концентрація 1,0 г/дм3). Експериментальні дослідження на щурах були проведені на базі віварію ННЦ «ІЕКВМ». У якості об’єкта досліджень було використано 140 статевозрілих щурів-самців лінії Вістар з початковою масою (220–230) г. За принципом аналогів було сформовано 4 групи тварин по 35 щурів у кожній. Упродовж експерименту тварини контрольної групи отримували питну воду без добавок; щурам І дослідної групи випоювали розчин NP LaVO4:Eu3+ у дозі 0,2 мг/дм3 (≈ 0,03 мг/кг маси тіла); ІІ дослідної групи – у дозі 1,0 мг/дм3 (≈ 0,15 мг/кг маси тіла) і щурам ІІІ дослідної групи – у дозі 2,0 мг/дм3 (≈ 0,30 мг/кг маси тіла). Випоювання здійснювали протягом 56 діб, потім його завершували і спостерігали за щурами ще 14 діб. Як стресовий фактор використовували незбалансований за поживними речовинами раціон. В результаті виконання роботи установлено, що за умов кормового стресу NP LaVO4:Eu3+ у дозах 0,2 і 1,0 мг/дм3 питної води (≈ 0,03 і ≈0,15 мг/кг маси тіла) проявляють адаптогенну дію на організм білих щурів із оптимальним терміном застосування – 56 і 28 діб відповідно. Проте, тривале пероральне введення NP LaVO4:Eu3+ у дозі 2,0 мг/дм3 питної води (≈ 0,30 мг/кг маси тіла) в організмі щурів спричинює гепато(цито-)токсичну дію, що має незворотній характер. Перспективою подальших досліджень у цьому напрямку є визначення розподілу Лантану в організмі білих щурів за умов кормового стресу.

In our research, we were interested in the actual presence of adaptive or negative reactions in the wall of the small intestine of white rats under the influence of gadolinium orthovanadate nanoparticles in the range of doses (≈0.03-0.3 mg/kg of body weight) under conditions of food stress (due to an excess of fiber and lack of protein in the diet) and their degree of manifestation, since this type of ration disproportion occurs quite often in Ukraine. Nanoparticles of gadolinium orthovanadate have a significant potential for use in animal husbandry and poultry farming, as in the range of doses of 0.03-0.15 mg/kg of body weight, they prevent negative effects on the intestinal mucosa, even in conditions of feed stress. It has been established that administration of gadolinium orthovanadate nanoparticles in doses of 0.03 and 0.15 mg/kg of body weight to white rats with drinking water for 56 and 28 days, respectively, leads to activation of the mechanical and immunological barrier of the mucous membrane, as indicated by an increase goblet cells, hyperplasia of enterocytes of some crypts, thickening of villi and infiltration by lymphocytes of the own plate, which reach the control level 14 days after stopping their administration. However, increasing the dose of gadolinium orthovanadate nanoparticles to 0.3 mg/kg of body weight in conditions of food stress leads to the depletion of the adaptive capabilities of the intestinal mucosa and excessive activation of the immunological barrier, which were manifested by dystrophic changes from the 14th day of administration, which deepened to the 56th day and do not level off after 14 days after stopping administration.