Aim:This study was designed to investigate the synergistic effect of the combined action of probiotic bacterial strains (Bifidobacterium adolescentis and Lactobacillus acidophilus) and Quercus cortex extract as biologically active substances in the feed on the immunity and productivity of Gallus gallus domesticus.Materials and Methods:For the experiment, 120 7-day-old broiler chickens were selected (4 groups, n=30, 3 replicates with 10 birds in each group). The groups were as follows: The reference group - basic diet (BD); experimental Group I - BD + Q. cortex extract (Q. cortex), 2.5 ml/kg of body weight; experimental Group II - BD + probiotic preparation based on B. adolescentis, 80.0 million colony-forming units (CFU), and L. acidophilus, 1.0 million CFU (dosage in accordance with the recommendations of the manufacturer); and experimental Group III - BD + probiotic + extract of Q. cortex. The following methods of study were used: Chemiluminescence and biochemical and hematological analysis.Results:The results of the experiment showed a slight decrease in the level of leukocytes in Groups II (p≤0.05) and III, and of hemoglobin in Group III (p≤0.05), compared to the reference group. The level of alanine aminotransferase and aspartate aminotransferase in Group II was higher than both the reference group (p≤0.05) and the other groups. Introduction of Q. cortex extract into the diet increased the level of triglycerides (p≤0.05) and urea in the blood serum. The combined use of probiotic preparations and the extract resulted in an increase in the level of iron in the blood serum by 78.1% (p≤0.05) in Group III. An increase in indicators of the antioxidant system (catalase increased in Group I by 27.2% (p≤0.05) and by 3.0–12.7% in other groups; superoxide dismutase increased by 3.0–13.2%) and nonspecific immunity (β-lysine increased by 8.8–16.0%) was noted. Introduction of the extract and probiotic preparation into the diet contributed to increasing the live weight of chickens at the age of 15 days by 5.9 and 7.4%, respectively (p≤0.05). In experimental Group II, this trend continued, and by the end of the period, the weight of animals exceeded that of their peers in other groups by 0.7-7.0%. Given the high preservation rate of poultry in the II and III Groups, and the low feed consumption per 1 kg of live weight gain (by 3.1–6.7%), the efficiency of growth was higher than in the reference group.Conclusion:Thus, the combined use of probiotic strains of bacteria and Q. cortex extract helped to increase the antioxidant activity of the organism and antimicrobial components of blood plasma compared with broiler chickens with similar growth rates but without the supplementation of this combination.

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A b s t r a c tTo date, numerous studies are focused on searching for alternatives to antibiotics with similar antimicrobial and growth-stimulating effects that do not cause bacterial resistance and potential side effects for animals. Promising phytogenic compounds have been also recognized as potential alternatives to antibiotics in feeds. One of the problems of phytogenic compound use is the unstable chemical composition of plant extracts, depending on the conditions of growth, distribution area and other factors, so the question arises of extracting some substances with the known properties or designing their compositions. In this paper, it has been shown for the first time that a dietary composition of biologically active substances of Quercus cortex helps to maintain productivity and improves the immunomodulating state of Smena 8 poultry cross broilers. In our experiment, a composition of substances (CS) extracted from Quercus cortex and chemically synthesized («Acros Organics B.V.B.A.», Belgium) was used, including 2-n-propylresorcinol (98 %, AVH27024); 4-hydroxy-3methoxybenzaldehyde (99 %, AC14082-1000); 7-hydroxycoumarin (99 %, AC12111-0250); 3,4,5trimethoxyphenol (98.5 %, AC18914-0050); scopoletin (95 %, AC30290-0010); coniferyl alcohol (98 %, AL22373-5) with a confirmed anti-QS effect. A total of 120 broiler chickens aged 7 days were divided into 4 groups (n = 30) by analogue method. Control group was fed with the basic diet (BD). BD + CS 1 (1 ml/kg of live weight), BD + CS 2 (2 ml/kg of lw), and BD + CS 3 (3 ml/kg lw) were used for group 1, group 2, and group 3, respectively. In the experimental groups, as compared to the control, the number of blood leukocytes increased by 19.2-28.5 % (P  0.05), blood lymphocytes were higher by 24.4, 36.2 % (P  0.05) and 44.0 % (P  0.05), blood monocytes were higher by 23.5, 23.5 and 29.4 % (Р  0.05), and blood granulocyte counts were higher by 12.3 % (Р  0.05), 5.7 and 9.5 %. The blood ALT activity in the group 2 and group 3 exceeded the control value by 13.2 % (P  0.05). The level of GGT tended to decrease in the group 2 and group 3, along with a significant decrease in LDH by 17.6-22.5 % (P  0.05). The intake of the CS as a feed additive was accompanied by an increase in blood SOD levels in the test groups, the highest concentration being observed in the group 1 (95.3 %). The catalase indices had similar patterns. Dietary composition of biologically active substances promoted a 16.4 % increase (P  0.05) in blood -lysine levels in the group 1. Within 4 weeks, the dietary CSs led to an increase in the live weight of the poultry of the group 2 and groups 3 by 12.6-15.0 % (P  0.05) when compared to the group 1. In the group 1, the birds grew more rapidly with a 100 % survival rate of the herd, in contrast to the remaining groups with the survival index of 71 to 85 %. These contributed to an insignificant increase in the bird live weight at the end of the experiment (day 42) by 1.9 % (P  0.05) compared to the control group. Thus, feeding broiler chickens with...

Aim:Modern methods of producing poultry meat without the use of antibiotics are known, and it is possible to achieve the desired conditions, including the use of herbal preparations. In addition, it is known that metabolites of medicinal plants are inhibitors of the quorum sensing system in bacteria. The aim of the present study was to determine the effect of Quercus cortex extract in a reduced dose on the productivity and body state of healthy chicken broilers.Materials and Methods:For the experiment, 120 heads of 7-day-old healthy broiler chickens were selected, and they were divided into four groups (n=30, 3 replicates of 10 birds in each group) by the analog method. The composition of diets of the experimental Groups I and II additionally included Q. cortex extract and Groups II and III included an enzyme preparation containing glucoamylase and concomitant cellulolytic enzymes. The following methods of study were used; gas chromatography–mass spectrometry, mass spectrometry and atomic emission spectrometry, and hematological analysis.Results:It was established that the increase in live weight of broiler chickens in experimental groups exceeded the analogous indicator in the control group by 3.1-16.6%, and feed intake within the entire experimental period increased by 2.6-15.4%, against a background of decreasing feed consumption for a weight gain of 1 kg of live weight (by 3.7-9.2%). There was an increase in iron concentration in blood of broiler chickens in Groups I and II (7.8-11.8%), in liver (23.7-92.4%, p≤0.05), and in spleen (53.9-77.7%, р≤0.05) against the background of a decrease in muscle tissue. A decreased content of monocytes and granulocytes was found, especially in experimental Group I.Conclusion:In the experiment, it was shown for the first time that the inclusion of Q. cortex extract in an enzyme-containing diet (anti-quarantine substances) was found to increase the productivity of poultry.