The tone of the autonomic nervous system, protein metabolism and enzymes in Cobb-500 crossbred chickens aged 35 and 60 days were studied. The experiment involved 24 chickens, 8 in each group. In birds, the tone of the autonomic nervous system was determined by the method of variation pulsometry. The essence of the method is to record the effect of sympathetic and parasympathetic systems on heart rate in chickens. The effect was determined by recording one hundred consecutive cardio intervals and counting the time interval between each cardiocycle. Venous blood samples were taken from each individual at the age of 35 and 60 days to determine the indicators of protein metabolism (total protein, albumin, globulins) and lipid peroxidation depending on the tone of the autonomic nervous system. It was found that the antioxidant level in chickens with a predominance of the sympathetic division prevailed in all other groups regardless of the age of the bird. At 35 days of age, plasma concentrations of diene conjugates were significantly higher in normatonics and vagotonics (P ˂ 0.05). There was a higher level of activity of ketodienes and Schiff bases in chickens with a predominance of the sympathetic division of autonomic nervous regulation compared with normotonics and vagotonics (P ˂ 0.01). The content of total protein, albumin and globulins prevailed in normotonic hens and was the lowest in vagotonic hens at the age of 35 days. The two-month-old bird with a dominant parasympathetic division of the autonomic nervous system and normotonic hens had the highest levels of total protein, globulins, and conversely, sympathicotonic hens outnumbered the latter in albumin levels. Histidine content was highest in chickens with a balanced type of autonomic nervous system compared to sympathicotonics and vagotonics (P ˂ 0.05). The concentration of sulfur-containing amino acid methionine was highest in vagotonic chickens (P < 0.05) compared with sympathicotonics. Threonine was highest in sympathicotonics compared with other groups of animals and significantly outweighed vagotonics (P < 0.05). The level of lipid peroxidation products in 60-day-old sympathicotonic chickens was consistently higher in contrast to normotonics and vagotonics. At the same time there was the smallest increase in the activity of diene conjugates and ketodienes (P < 0.05) in chickens with a dominant sympathetic division of the autonomic nervous system, which indicates a slowdown in the accumulation of the final products of lipid peroxidation.

The tone of the autonomic nervous system, protein metabolism and the activity of the antioxidant system in Cobb-500 cross chickens aged 35 and 60 days were researched. The experiment involved 24 chickens, 8 in each group. In birds, the tone of the autonomic nervous system was determined by the method of variation pulsometry by recording the influence of the sympathetic and parasympathetic systems on the heart rate in chickens. The effect was determined by counting one hundred consecutive cardio intervals and the time interval between each cardiocycle. Venous blood samples were taken from each individual at the age of 35 and 60 days to determine protein metabolism (total protein, albumin, globulins), enzymatic and non-enzymatic links of the antioxidant system and lipid peroxidation depending on the tone of the autonomic nervous system. It was found that the antioxidant level in chickens with a predominance of the sympathetic division prevailed in all other groups regardless of the age of the bird. At 35 days of age, plasma concentrations of diene conjugates were significantly higher in normatonics and vagotonics (P ˂ 0.05). There was a higher level of activity of ketodienes and Schiff bases in chickens with a predominance of the sympathetic division of autonomic nervous regulation compared with normotonics and vagotonics (P ˂ 0.01). The content of total protein, albumin and globulins prevailed in normotonic hens and was the lowest in vagotonic hens at the age of 35 days. The two-month-old bird with a dominant parasympathetic division of the autonomic nervous system and normotonic hens had the highest levels of total protein, globulins, and conversely, sympathicotonic hens outnumbered the latter in albumin levels. Histidine content was highest in chickens with a balanced type of autonomic nervous system compared to sympathicotonics and vagotonics (P ˂ 0.05). The concentration of sulfur-containing amino acid methionine was highest in vagotonic chickens (P < 0.05) compared with sympathicotonics. Threonine was highest in sympathicotonics compared with other groups of animals and significantly outweighed vagotonics (P < 0.05). The level of lipid peroxidation products in 60-day-old sympathicotonic chickens was consistently higher in contrast to normotonics and vagotonics. At the same time there was the smallest increase in the activity of diene conjugates and ketodienes (P < 0.05) in chickens with a dominant sympathetic division of the autonomic nervous system, which indicates a slowdown in the accumulation of the final products of lipid peroxidation. It was found that the predominance of sympathetic tone is characterized by low activity of enzymes of the antioxidant system and tocopherol (P < 0.001, P < 0.01) at 35 and 60 days of age. Indicators of the activity of the antioxidant system had the highest level in vagotonic chickens of the studied age period (P < 0.05, P < 0.01, P < 0.001). The relationship between catalase and tocopherol levels in vagotonic chickens at 35 days of age, which increases at 60 days of age r = 0.53 (P < 0.01) was found.

The autonomic nervous system regulates the work of internal organs and the intensity of metabolic processes in animals and birds. However, the question of the influence of autonomous balance types on the productivity of chickens is insufficiently studied. The aim of work was to study the growth intensity of broiler chickens depending on the typological features of the tone of the autonomic nervous system. Cobb-500 crossbreed meat-producing chickens were used for the study. To study the typological features of autonomic tone in the experimental bird, an individual electrocardiogram was recorded, and one hundred R-R cardio intervals were calculated, which were processed by the method of variation pulsometry according to R. M. Baevsky. This allowed to divide all chickens into three groups: sympathotonics, normotonics and vagotonics. To determine the influence of the types of autonomic nervous regulation on the increase in live weight, the birds were weighed at 35 and 60 days of age and the indicators characterizing the growth intensity were calculated. As a result of the conducted researches it was established that the live weight in chickens-vagotonics of 35 days of age is probably higher by 11.29 % (p<0.05) than in chickens-sympathotonic. At the age of 60 days, vagotonic hens probably prevailed (p<0.001) in terms of live weight over chickens-normotonics. In addition, chickensvagotonics were characterized by the highest rates of absolute, average daily and gross live weight gain compared to other types. Determining the types of autonomic nervous regulation and their relationship to live weight gain in chickens makes it possible to establish new methods for detecting birds with the highest productivity. This allows you to reduce the cost of fattening low-yielding poultry at an early stage of rearing, increase the number of high-yielding chickens, and get higher profits and meat production of broiler chickens.

The regulation of metabolic processes and maintenance of a stable internal environment of the body is the role of the autonomic nervous system (ANS). It influences all systems and organs, thus along with the neuro-humoral system providing control over the metabolism of proteins, fats and carbohydrates. Amino acids, as structural units of any protein molecule, are essential for the metabolism of proteins, enzymes and hormones. Certain amino acids are involved in neutralizing free radicals and are a donor of metal groups, can act as an energy source in case of a deficiency of carbohydrates and fats, and be structural units of connective tissue. Exchange of these compounds and their regulation by ANS have not been studied sufficiently, therefore, it is necessary to carry out research in this direction. The studies were aimed at finding the presence of the regulatory effect of ANS on the content of individual amino acids in the blood serum of 60-day-old Cobb-500 chickens. Determination of the ANS tone in Cobb-500 chickens at the age of 30–35 days was determined by the method of variation pulsometry. Electrocardiographic examination was performed in a quiet room without the use of sedatives. At the age of 60 days, blood was obtained from the saphenous vein of the chickens’ shoulder. Blood was sampled from 10 am to 1 pm, after a short fasting (2:00). It was found that sympathicotonic chickens had a higher content of individual amino acids compared to normotonics and vagotonics. In vagotonic chickens, the content of glycine and serine in the blood serum significantly exceeded the rate of chickens with a balanced tone of ANS. Correlative relationships between amino acid content were highly significant in poultry with balanced ANS tone. Vagotonic chickens had the highest correlations between ANS tone, heart rate and amino acid content (trend). Correlative relationships were present between ANS and body weight of chickens of different groups, serum protein. The correlation between total serum protein and body weight of chickens was different depending on the tone of the ANS. Fisher’s test revealed a significant effect of balanced ANS tone on the content of valine, serine and glycine and the weight of chickens. The effect of ANS tone on weight in vagotonic birds was high.

Regulation of metabolic and physiological functions of the whole organismis a complex neurohumoral process. Its functioning is supported by many organs and systems. One of the main roles here is performed by the autonomic nervous system. The mutual influence of its departments – sympathetic and parasympathetic, provide stable homeostasis and balanced work of all organs and structures. The sympathetic department is responsible for energy resource mobilization and adaptation. Without its influence, a rapid response of the cardiovascular and endocrine systems to the body's needs arising from changes in the internal or external environment is impossible. Dominant sympathetic tone provides activation of gluconeogenes is and glycogenolysis, lipolysis, etc. In contrast, the parasympathetic division is responsible for energy conservation and nutrient accumulation. Its dominant activity causes a decrease in heart rate, increase in pupil diameter depending on light flux, secretion of saliva and digestive juices, acceleration of motility of the gastrointestinal tract. However, to date, the existence of the influence of the tone of the autonomic nervous system on the content of proteins and their derivatives in the serum has not been studied enough. Proteins and their main components – aminoacids are indispensable in the construction and functioning of the whole organism of all living beings. Deficiency or absence of at least one essential amino acid can lead to disruption of various functional systems of the body, adverse health effects, and in the case of long-term deficiency and death. Studies to determine the content of amino acids in the serum of chickens with different dominant tone of the autonomic nervous system revealed different contents of individual cyclic and acyclic amino acids. The content of phenylalanine in sympathicotonic chickens differed significantly compared with the bird, which had a balanced tone (P˂0.05). In contrast, the tyrosine content was almost the same in all groups of animals. The amino acids leucine/ isoleucine and alanine were not significantly predominant in the different samples, but tended to be higher in sympathetic and vagotonic chickens. The study suggests that the dominance of the sympathetic and parasympathetic divisions of the autonomic nervous system or their balanced tone on the content of amino acids in the serum of chickens. Key words: sympathicotonia, vagotonia, normotony, phenylalanine, alanine, leucine/isoleucine, tyrosine.