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.

Health and performance management systems should focus on early detection and subsequent prevention of physiological imbalances in dairy herds. Therefore, the need for constant monitoring of the state of health of cows of various physiological and technological groups, in particular markers of protein metabolism, is urgent. The content of total protein in blood serum of deep-bodied cows and heifers was established in the range of 58.3–102.7 g/l (77.2± 0.48 g/l). Disorders of its metabolism were diagnosed in 35.4% of animals, and in most of them (20.4%), mainly in heifers, it was manifested by hypoproteinemia. The optimal content of albumins was established in 81.2% of the studied herd with an average value of 41.1± 0.26%, including in 74.6% of dry cows and in 91.7% of heifers. Hypoalbuminemia was diagnosed in an average of 18.8% of animals, including in 25.4% of cows and in 8.3% of heifers. In dry cows, the pathology arose mainly as a result of the development of dystrophic processes in the liver in the previous lactation periods, in heifers, primarily due to a protein deficiency in the diet. In 72.2% of the studied animals, 40–10 days before the expected birth, there are no violations of the colloidal stability of coarsely dispersed proteins. In 14.1% of blood serum samples, the test was weakly positive (++), in 11.5% - positive (+++) and strongly positive (++++). In another 2.2% of cows, the formation of a dense clot of a milky white color in the test tube was ascertained already after 4–7 hours. after the reaction (the test is hyperpositive - +++++). Optimal values of urea metabolism in blood serum were established in 48.1% of dry cows and in 55.0% of heifers (3.53± 0.043 mmol/l; 1.82–6.80). A decrease in its content was diagnosed in 49.7 and 45.0% of animals, respectively. The metabolism of creatinine in blood serum was optimal in 94.8% of the examined dry cows and in 94.1% of the heifers, and its values were within the reference values. Hypercreatininemia was diagnosed in 5.4% of the studied animal population, which can probably be caused by the development of dystrophic processes in the glomeruli of the kidneys. Key words: metabolism, diagnostics, proteins, albumins, urea, creatinine, liver, deep-bodied cows, heifers.

Perosis is a common metabolic disease of industrial birds, especially broiler chickens. It leads to a violation of the balance of biotic substances in the body of chickens, which is clinically manifested by the curvature of the limbs, reduced mobility, and, consequently, reduced profitability of meat production. Prevention of perosis is possible provided that chickens receive a sufficient amount of manganese in a biologically available form. Studies were conducted to determine the efficiency of use of manganese chelates (pantothenate and lysinate) for prevention of perosis in broiler chickens. Efficacy was confirmed by examining changes in the clinical state, indicators of protein and mineral metabolism, as well as meat productivity of birds. For the experiment, broiler chickens of the Cobb-500 cross were taken at the age of 14 days. The birds of the control group received a standard diet, and the chickens from two experimental groups additionally received manganese pantothenate and lysinate with water during the critical period for the development of perosis – 14–28 days old. After 14 days of administration of manganese pantothenate and lysinate, the weight of the experimental birds at the age of 28 days was greater by 133.6 g (+11.0%) and 142.2 g (+11.7%), respectively, in comparison with poultry of the control group. Additional provision of manganese pantothenate and lysinate to chickens of the experimental groups contributed to an increase in the blood serum total protein concentration by 11.0% and 12.8 %, albumin – by 10.1% and 8.2%, magnesium – by 8.1% and 9.0% and manganese – by 29.6% and 26.9%, respectively, compared with indicies of the control group birds. The use of manganese chelates in the form of pantothenate (0.2 mL/L of water) and a lysinate (0.5 mL/L) during the 14–28th days of broiler chickens’ rearing provides 100% prevention of perosis. This reduces the death of broiler chickens, increases body weight, and, as a result, significantly increases the profitability of meat production.