Assessment of Lipid Metabolism in Broilers against Plant Extract and Probiotic Substance or Their Combined Use

In course of our research, we studied content of chemical elements in body of broiler chickens, lipid content in body and blood serum and change composition of fatty acid of muscles under influence of probiotic (Lactobifadol) and oak bark (Quercus cortex) extract introduced into the diet, both separately and com-bined. Studies were carried out in vivarium of Federal Research Centre of Biological Systems and Agro-technologies of Russian Academy of Sciences on broiler crosses Smena 8 (n=120). For experiment, 7-day broiler chickens were selected, they were divided into 4 groups by method of analogues (n=30). According to experimental design, control group received basal diet (BD), group I - BD + Quercus cortex extract (1 mL/kg live weight), group II - BD + probiotic Lactobifadol (0.3 g/kg), and group III - BD + oak bark ex-tract (2.5 mL/kg body weight) + Lactobifadol (0.3 g/kg of live weight). Thus, combined introduction of oak bark extract and Lactobifadol into diet of studied birds led to decrease content of dry matter by 13.5% rela-tive to control. Oak bark extract contributed to increase in protein content by 7.3% (P≤0.05), relative to control. Level of fat decreased by 27.9% (P≤0.05) in comparison to control after the combined use of the extract and the probiotic. After the use of oak bark extract, chemical composition parameters significantly exceeded dry matter content of the control group by 10.8% (P≤0.05) and fat by 45.7% (P≤0.05), the protein level decreased by 2.4 % (P≤0.05), relative to the control. The combined introduction of oak bark extract and Lactobifadol into the diet of the studied birds contributed to a significant decrease in cholesterol on the 42nd day by 20.3% (P≤0.05), relative to the control. The level of triglycerides in the III experimental group also significantly decreased on the 21st day by 22.4% (P≤0.05), relative to the control group. Thus, we have shown that the use of oak bark extract in the diet of broiler chickens, both separately and together with the introduction of Lactobifadol probiotic, had a positive effect on blood serum lipid content of broilers and a decrease fat content in the carcass of broiler chickens. It was the most pronounced after the combined use of extract and probiotic.