Comparative evaluation of the effect of the Quercus cortex extract and biologically active substances of plant origin on health and scar digestion

The paper studies effects of the Quercus corte x water extract (group II) and synthesized biologically active substances of the Quercus cortex extract (group III) on the dry matter digestibility, hematological parameters and the elemental composition of the scar fluid. It was identified that additives have a dose-dependent effect on the dry matter digestibility. They improve digestibility by 12.46% (P≤0.001) (group II) and 17.68% (group III). Among the hematological parameters, the number of lymphocytes increased by 34.07% (group II) and by 44.74% (group III); the hemoglobin concentration increased by 5.11% (group III). The serum iron decreased by 23.26% (P≤0.05) (group II) increased by 7.29% (group III). Experimental additives infleunce the microelement composition of the ruminal fluid reducing the concentration of Fe, CoCr, Ni and increasing the concentration of Mn, Cu, Zn values. The results obtained require further research.


Introduction
Currently, in order to correct the natural resistance and normalize metabolism in cattle, biological active substances of plant origin whose valuable components are well absorbed are used. In scientific and folk medicine preparations from aqueous plant extracts of larch wood, Siberian cedar and oak [1][2] are used.
Scientists found that biologically active substances have a positive effect on the mucous membrane of the digestive tract: they have an astringent effect similar to the tannic one, and contribute to the formation of a layer that reduces irritation of the mucous membrane [3].
When screening twenty medicinal plants used in medicine, a significant ability to inhibit the sensory quorum system of wild and mutant C. Violaceum strains was found in Quercus cortex extract, Betula verucosa buds and Eucalyptus viminalis leaves [4]. The content of biologically active systems in plants varies depending on various factors: parts, harvest seasons and geographic location, methods for producing additives [5]. Scientists conduct research on plant extracts, then carry out experiments adding isolated compounds of biologically active substances [6].
In addition, there is little information about the identification of compounds present in the additives, since most of the additives are complex extracts [7]. Therefore, it is recommended to identify chemical components in plant extracts in order to understand their effect on the elemental status of animals [8][9]. Data were expressed as mean values ± standard error of the mean. Statistical analysis was performed using Statistica 10.0 (StatSoft Inc., USA) and Microsoft Excel (Microsoft, USA). The significance of group differences was estimated using Student's t-test with p≤0.05.

Invitro study results
Invitro studies identified that dry matter digestibility increases due to the addition of biologically active substances Quercus cortex and an oak bark extract at various doses (Table 1). When making adding the Quercus cortex extract at the minimum dose, dry matter digestibility exceeded the control one by 5.42% (P <0.01). An increase in the dose to 3.3 mg/ml increased digestibility by 12.46% (P≤0.001). A further increase decreased digestibility.
When comparing two factors, it is clear that biologically active substances increase digestibility more as compared to the aqueous extract Quercus cortex. Invivo study results.

Morpho-biochemical blood parameters.
The Quercus cortex extract (group II) decreased the number of granulocytes and platelets by 28.94 and 3.41% (P≤0.05), respectively. The number of lymphocytes and erythrocytes increased by 34.07% and 0.34%, respectively.
Biologically active substances (group III) increased the hemoglobin content by 5.11% and decreased platelets by 48.3% (P≤0.01) ( Table 2). The Quercus cortex (group II) increased activity of ALT by 8.10%, and biologically active substances (group III) reduced activity of the enzyme by 18.81% (P≤0.01) ( Table 2).
Biologically active substances (group III) decreased the total protein content by 19.80% (P≤0.01) and 13.51% (P≤0.001), respectively. The remaining biochemical parameters were close to the control values.
The elemental composition of rumen fluid. The number of trace elements changed. 3 hours after the addition of the Quercus cortex extract (group II), the As concentration decreased by 50% (P≤0.001), Ni -by 26.92% (P≤0.001), and Feby 32.81% (P≤0.01). Cu decreased by 66.67% (P≤0.001), Mn -by 28.13% (P≤0.001), Znby 111.46% (P≤0.05 (Fig. 1).   (Fig. 4). In the experimental groups, the content of trace elements in the rumen fluid changed. Their higher content was observed 6 hours after addition of the extract due to the accumulation of chemicals during digestion.

Discussion
The Quercus cortex extract of biologically active substances increased digestibility by 12.46% (P≤0.001) and 17.68%; tQuercus cortex as a source of quercetin has antioxidant and anti-inflammatory effects increasing digestibility of nutrients in the rumen [12].
Quercus cortex as a source of tannin has no negative effect on fermentation. It has a positive effect on dry matter digestibility, energy metabolism and the use of protein in the rumen [13].  Inhibiting properties of medicinal plants and their extracts are associated with the participation of phenols and polyphenols (flavonoids) in reactions with radicals that accompany some diseases [14].
Quercus cortex and biologically active substances of plant origin changed morphological and biochemical blood parameters; the number of leukocytes, lymphocytes, monocytes, granulocytes increased [15] due to an increase in immunological activity and phagocytosis [16].
An increase in the content of leukocytes in group III is consistent with previous studies [17] performed using the thyme extract, where there was no significant increase in the level of leukocytes, but immunological reactions improved.
Feeding broiler chickens with Quercus cortex + artificially synthesized substances has a positive effect on the immunomodulating state and antioxidant activity, increases the content of in-lysine, serum superoxide dismutase and catalase [18].
The data obtained are similar to the data in [19], where a decrease in plasma iron was observed when feeding with Grape seed extracts.
Protein plays a leading role in complex biochemical processes; its content in the blood plasma indicates the physiological well-being of the body [20]. The concentration of total protein in the blood of calves increases as an adaptive-mobilization response. In the blood of experimental animals, the level of total protein is lower than the control value which indicates higher metabolism in the animals of the experimental group [21]. 50 g of dry matter of the oak bark extract added into the feed increased calcium and sodium twice; phosphorus and magnesium -1.7 and 1.8 times [22].
The Quercus cortex extract increased the Mn concentration due to its high concentration in the extract and its ability to form weak systems with chemical elements in the gastrointestinal tract [23].
In the experimental groups, the iron content decreased. It is in compliance with the report of a decrease in the content of zinc and copper in the liver of monogastric animals fed with plant products (extracts from grape marc) containing polyphenolic substances [24].

Conclusion
It was established that the Quercus cortex extract and synthesized biologically active substances of the Quercus cortex extract in cattle feeding have a dose-dependent effect on dry matter digestibility. Digestibility increased by 12.46% (P≤0.001) (group II) and 17.68% (group III) The number of lymphocytes increased by 34.07% (group II) and 44.74% (group III); the hemoglobin concentration increased by 5.11% (group III). Serum iron decreased by 23.26% (P≤0.05) (group II) and increased by 7.29% (group III). Experimental additives had an effect on the microelement composition of the rumen fluid reducing the concentration of Fe, CoCr, Ni and increasing the concentration of Mn, Cu, Zn. The results require further research.