Abstract
<jats:p>The article presents the results of an in vitro study of the effect of an organic phytonutrient based on skullcap herb extract on the digestibility of the microration and the metabolic activity of the microflora of the cattle rumen. The main purpose of the work was to identify correlations between the number of microbial populations of the rumen, the concentration of volatile fatty acids (VFA), nitrogen forms in the rumen fluid and the digestibility of various feed components. The experiment was performed using an ANKOM Daisy II incubator and scar fluid obtained from one fistulated bull. The microration was incubated without an additive (control) and with the introduction of a phytodrug in doses of 3.3, 5.0 and 6.7 mg per 1 g of dry matter of the feed, while each incubation option was performed in three repetitions (n = 3) to ensure statistical reliability of the results. The data obtained showed that the introduction of phytonutrients was accompanied by an increase in the digestibility of dry matter and protein in the diet, and also stimulated the metabolic activity of the microflora of the scar. The most pronounced positive correlation was found between the number of protozoa and the concentration of butyric acid (r = 0.95). Moderate positive associations were established between the digestibility of dry matter and the content of propionic and acetic acids (r = 0.73 and r = 0.71, respectively). The number of protozoa also showed moderate positive correlations with total (r = 0.72) and protein nitrogen (r = 0.78), while the number of bacteria showed a weak negative relationship with total nitrogen (r = -0.23). Thus, the results indicate that the organic phytodump has a stimulating effect on the microbial activity of the scar and improves the digestibility of feed components in vitro. At the same time, the revealed dependencies were correlational in nature and require further confirmation in in vivo experiments with cattle in order to assess the practical effectiveness of the herbal supplement, as well as to determine the optimal dosages and strategies for its use in the diet of animals.</jats:p>