The dissertation on competition of an educational and scientific degree of the Philosophy Doctor of field of knowledge 21 "Veterinary medicine" on a specialty 211 "Veterinary medicine". The work was performed at the Department of Normal and Pathological Physiology named after S.V. Stoyanovsky at Stepan Gzhytskyi National University of Veterinary Medicine and Biotechnologies Lviv. The presentation is planned in Stepan Gzhytskyi National University of Veterinary Medicine and Biotechnologies Lviv, 2021.
New data on the systematic study of the features of functional adaptation of the immune and antioxidant defense system of the broiler chickens cross "Kobb-500" at different stages of postnatal ontogenesis under the influence of combined stress (revaccination against cold stress). It was found from 30 to 45 days of life of broilers increase in the number of erythrocytes and leukocytes by 30.1 end 45.1 % (p<0.05), hemoglobin concentration - by 29.4% (p<0.05), hematocrit - by 29, 6% (p<0.05), an increase in the content of lipid hydroperoxides by 3.5 times (p<0.05), TBA-active products by 1.8 times (p<0.01) against the background of increasing the activity of superoxide dismutase by 23.3% and catalase - by 21.1% with a decrease in glutathione peroxidase activity by 2.2 times (p<0.05). From 15 to 45 days of age there is a doubling (p<0.05) the size of Peyer's patches and primary lymphoid nodules in their composition and the absence of secondary forms of structural organization.
The physiological state of the body of broiler chickens under the action of combined stress is characterized at the stage of anxiety by a decrease in hemoglobin concentration and hematocrit by an average of 16.6%, an increase in high-lead B-lymphocytes, undifferentiated subpopulations and low-lead T-lymphocytes, Gassal cells in the thymus, primary nodules of the spleen, low content of intermediate and final products against the background of high activity of the enzymatic link of the antioxidant system. At different stages of the resistance stage – a decrease in the number of erythrocytes and hemoglobin concentration by 3.4 - 6.5% against the background of increasing hematocrit by 37.0%, increasing the number of leukocytes by 17.2%, increase in the number of low-avid T-total lymphocytes by 25.8% (p<0.05) due to low- and high-avid T-helpers by 23.7% (p<0.05), T-suppressors - by 64.4% (p<0.01), the number of low- and high-lead B-lymphocytes by 29.6% (p<0.05), malnutrition of the cortical substance on the background of hypertrophy of the cerebral substance of the thymus lobes and halving (p<0.05) the number of Gassal cells; reducing the length and density of the lymphoid nodules of the bursa of Fabricius, the area of their cortical substance and the lymphoidization of the cerebral substance; increase in the size of spleen nodules and increase in their number by 48.3% (p<0.05), the content of lipid hydroperoxides and TBA-active products increases by 1.8-3.6 and 2.4 times against the background of a decrease in superoxide dismutase by 27.8% and glutathione peroxidase in 2.5-5, 4 times.
Immunological adaptation of broiler chickens on the background of combined stress, receiving "Reasil Humic Vet" + "Laktin" and "Reasil Humic Health", is manifested by a decrease in the number of T-total lymphocytes by 14,9 % (p<0.05) due to undifferentiated T-helpers by 13.4% (p<0.05), T-suppressors by 32.3 % (p<0.05), an increase in the number of B-lymphocytes by 16.3-21.6% (p<0.05) due to highly avid forms - by 35.0-67.0% (p<0.05), increased brain area against the background of a decrease in the area of the cortical zone in the thymus and in the lymphoid nodules of bursa, an average increase of 44.5% (p<0.05) in the number of thymic cells and of 33.6 % (р<0.05) in the number of spleen nodules with signs of delayed involutional processes of the thymus and bursa Fabricius, reducing the concentration of lipid hydroperoxides and TBA-active products by 32.8 and 42.5% (p<0.05 ) and increases the activity of the antioxidant defense system in the form of an increase in the activity of superoxide dismutase - by 35.8-46.6% (p<0.05), catalase - by 36.9-52.9% (p<0.05), glutathione peroxidase - by 22.7-33.4% (p<0.05) compared with the control. The feeding of the supplement "Reasil Humic Vet" + "Laktin", which increases body weight in 26 days after exposure to stress by 5.3 % (p <0.05), the average daily gain to 61.36 g / goal / day, the rate of preservation of livestock during stress - up to 96.5%.
Key words: physiological state, adaptation, immune system, antioxidant defense system, critical periods of ontogenesis, combined stress, biologically active feed additives, broiler chickens.
