Trace elements in the body of the bird are in small quantities, but their role in productivity remains important. In order to get a quality carcass at the slaughterhouse, you need a constant supply of nutrients and, last but not least, microelements. Zinc and Manganese are essential trace elements that affect the growth and development of birds. And their deficiency in the body has a negative effect on the productivity of birds. In the diet of broilers trace elements are mainly added with a premix in the form of inorganic salts (sulfates, carbonates). However, these micronutrient compounds in the body of the bird are insufficiently absorbed, and increasing the dose of their introduction can cause toxicosis. Therefore, in order to prevent microelementosis, it is more appropriate to use organic compounds (chelates), which have a much higher level of bioavailability and less release into the environment. This review article describes the prophylactic efficacy of Zinc and Manganese chelates in micronutrient deficiencies in broiler chickens and laying hens. With a deficiency of a particular trace element develop metabolic disorders and other pathologies (perosis, etc.). Based on the presented data, it can be concluded that the use of organic forms of trace elements in poultry feeding is a better alternative to inorganic sources, as they can be used in smaller quantities. But due to their greater bioavailability, they are better absorbed, which has a positive effect on the productivity of broilers. Since knowledge about the use of chelated forms of trace elements in comparison with inorganic forms (salts, sulfates, etc.) in the diet of poultry is still poorly understood, it is necessary to further conduct research to prevent micronutrient deficiencies in these compounds.

Perosis is one of the most common leg pathologies in broiler chickens, during the period of intense weight gain – at the age of 14–35 days. Due to manganese deficiency, the number of sick birds can reach up to 5% of the flock. These studies were carried out in order to establish changes in some indicators of protein, macro- and micromineral metabolism in the blood serum of clinically healthy broiler chickens and birds with perosis at 14, 21 and 28 days of age. A batch of 2,000 Cobb-500 crossbred broiler chickens was selected. Two groups of chickens were directly involved in the research, in which blood was taken at the age of 14, 21 and 28 days: healthy birds and those with perosis signs. Clinical studies showed that 8.0% of chickens on 28th day suffered from perosis. Trace mineral biochemical parameters of serum and blood of broiler chickens with perosis on the 28th day of life significantly differed from those of healthy birds (manganese and zinc). It was found that on the 28th day of life the weight of chickens with perosis was reduced by 42.7%, causing a loss of weight 88 kg per batch of 2000 birds, with a consumption of feed 140 kg. The obtained data will allow the development of early perosis prevention schemes in broiler chickens, which will help manage production losses and increase its profitability. On farms, to prevent the occurrence of perosis, it is necessary to take into account the technological factors of the production of compound feed. Also, an increase in the level of total protein and albumin in serum in the blood may indicate inflammatory processes and dehydration of the body. Therefore, it is better to site a sick bird separately for rearing or hand over to a sanitary culling.

The rapid growth of demand for poultry products requires its sufficient production by specialized farms of various forms of ownership. However, such production needs are not always adequate to the selection approach, the incubation component, the basic requirements of veterinary and sanitary and zoohygienic support, breed and age characteristics of keeping and raising poultry. Therefore, one of the crucial components of obtaining biologically complete, high-quality and fast-paying products of the poultry industry, including all stages of its production, is human support of the main links of ontogenesis (development after birth) of the bird. The issue of not only the creation of the genetic potential of the parent bird of different species and areas of productivity, but also the provision of veterinary and sanitary conditions for their maintenance, breeding and breeding remains relevant. However, the current economic conditions have forced the heads of enterprises and veterinary departments to some extent bypass the planned laboratory tests of feed, water and blood, which, although not complete, but informative enough to trace the main periods of growth and development of the bird. Slight deterioration of the mode and quality of feeding, changes in the parameters of the microclimate are reflected in changes in blood parameters. And what about the spoilage of feed, water, violation of veterinary and sanitary maintenance of poultry: the lack of preventive treatments with vitamin-mineral, hepatoprotective and enzyme preparations, pre- and probiotics. Which can lead to metabolic disorders in poultry. Which can occur due to disorders of protein, lipid, carbohydrate, vitamin, macro- and micromineral metabolism. As a result, there are significantly popular diseases such as: uric acid diathesis, cannibalism, osteoporosis and osteomalacia, perosis, rickets, obesity, E-hypovitaminosis. Further reducing productivity, which leads to large economic losses on farms.

Culling due to poor condition, weight loss, mortalityand, as a result, economic losses due to perosa, accordingto various estimates, 1-5% of the group of birds. Due to thedysfunction of the limbs, the bird can suffer from a numberof diseases. Lack of essential nutrients play an important rolein the development of perosis in poultry. Often in farms dueto cost savings, reduce the cost of feed for broilers, which inturn can lead to metabolic disorders in poultry. Therefore, thediagnosis of these disorders requires new approaches. Modernscience is increasingly inclined to non-invasive diagnosis ofmetabolic pathologies. In human medicine, nails and hair areused to study persistent micronutrient deficiencies. And inveterinary medicine in the study of micronutrient deficienciesas a method of non-invasive diagnosis using animal hair.According to the results of our research, theconcentrations of microelements (Zn, Mn) in the feathers of14, 21 and 28-days-old clinically healthy and feathery broilerchickens were determined. On day 14 of the disease, theconcentration of Zinc and Manganese in broiler chickens withperosis was 65.6 ± 2.73 and 17.4 ± 0.79 μg / g, which wasprobably higher than in clinically healthy birds 46.5 ± 1.57(p <0.001) and 10.9 ± 0.80 (p <0.001) μg / g. Analyzing the indicators of micronutrients in the clawsof patients with feathers of broiler chickens of 28 days ofage, the content of Manganese was 10.2 ± 0.51 μg / g, whichis probably less than in clinically healthy birds 15.7 ± 0.97μg / g (p < 0.01). The concentration of zinc in the claws ofhealthy birds is 127.6 ± 3.65 μg / g, which tended to increasecompared to that in healthy birds - 98.3 ± 5.40 μg / g.The results of the analysis show that in birds with signs ofperosis, Zinc and Manganese accumulate in higher concentrations in the feathers compared to clinically healthy chickens. Inturn, the concentration of these elements in the claws in chickens with feathers relative to healthy birds of the group decreases. Key words: trace elements, non-invasive diagnostics,metabolic pathologies, avian.

The results of the application of a complex of Zinc and Manganese chelates to protein, macro- and micro-mineral exchanges in the body of broiler chickens of the Cobb 500 cross-breed are presented. The administration of Zn and Mn chelates in a dose of 0,2 ml/l for chicken broilers of 23 days of age (1st experimental group) during 14 days influenced the increase in the total protein content to 35,3±0,8 g/l, which is 8 % higher compared with the control – 32,5±0,7 g/l (p<0,01 ) The concentration of total Calcium in serum of broiler chickens 37-day-old (end of trial) was higher in the first experimental group by 7,3 % (2,05±0,06 mmol/l) compared to control – 1,9±0,03 mmol/l. In the second group, where chelates were administered in a dose of 0,4 ml/l of water, the Calcium content was 2,0±0,02 mmol/l, which is 5 % more than the control group. The two-week application of Zn and Mn chelates also led to an increase in the level of inorganic Phosphorus in the serum of the first group to 2,6±0,12 mmol/l (+ 11,5 %) compared with the control group. After administration of chelates Zn and Mn at doses of 0,2 ml/l water, the Zinc content was higher by 4,3% (23,5±0,2 μmol/l) compared to control – 22,5±0,34 μmol/l (p<0,01). In the second group, where the dose of chelates was 0,4 ml/l, the concentration of Zinc was 23,6±0,16 μmol/l, which is more than 4,6 % for control (p<0,01). At the end of the study, the content of Manganese in serum of broiler chickens in the first group was 1,9±0,07 μmol/l (p<0,05), which is 10,4% higher compared with the control – 1,7±0,06 μmol/l (3rd sampling). The level of this element in the second group was 2,0±0,08 μmol/l (p<0,01), which is higher by 16,7 % relative to the control. At the end of the experiment, the coupon concentration in the first and second experimental groups was 12,6 and 9,3 % higher, compared with control, 7,0±0,37 μmol/l. In turn, the serum Ferrum content of the first group was greater by 9,3 % (19,3±0,69 μmol/l), and the second by 6,7 % (18,8±0,47 μmol/l) compared to the bird of the control group. Key words: chicken broilers, chelates, Zinc, Manganese, Cuprom, Ferrum, metabolism.