Background and Aim: Ensuring the genetic potential of ruminants through nutrition studies using medicinal plants and trace element metals is an urgent task. This study aimed to study the effect of Artemisia absinthium L. (Asteraceae) herb plant separately and in combination with cobalt (II) chloride (CoCl2) chelate compounds on the course of metabolic processes in the rumen, methane concentration, and biochemical blood parameters in bulls. Materials and Methods: Control group (BD: Basal diet); experimental Group I – BD + A. absinthium herb at a dose of 2.0 g/kg dry matter (DM), experimental Group II – BD + A. absinthium herb at a dose of 2.0 g/kg DM + CoCl2 (1.5 mg/kg), and experimental Group III – BD + CoCl2 were set (1.5 mg/kg). The study was conducted on 16 beef bulls (Kazakh white-headed breed) aged 13–14 months, with an average live weight of 330–335 kg. Enzymatic processes in the rumen were studied, including the level of volatile fatty acids (using the gas chromatography method), nitrogen and its fractions (using the Kjeldahl method), methane concentration, and morphological and biochemical blood composition. Results: There was a decrease in the concentration of acetic acid in experimental group I (15.9%) (p < 0.05) and in the III group (60.3%) and propionic acid in all experimental groups by 5.6%–47.3% (p < 0.05). Feeding A. absinthium herb as part of the diet of experimental Group I contributed to a decrease in methane concentration by 17.8% (p = 0.05) and the lowest methane concentration was noted for experimental Group III. It was less than in control by 59.1% (p < 0.05). An increase in the concentration of glucose, total protein, and creatinine was found in the experimental groups (p < 0.05). The digestibility of organic matter (3.5%), crude fiber (3.6%), and hemicellulose (11.0%) increased with the feeding of A. absinthium herb. Conclusion: Thus, using biocomplexes based on A. absinthium herb and CoCl2 do not harm the rumen fermentation of cattle. Still, further microbiome studies are required to evaluate the effects of A. absinthium on cattle properly.

The use of GWASs in agriculture allows associations between SNPs and quantitative or qualitative traits in cattle to be estimated. This study investigated the relationships among a number of economically useful carcass traits (slaughter weight, meat yield, and meat marbling) with a group of SNPs that can act as DNA markers. Blood samples from Aberdeen Angus bulls (n = 260) were used as material for SNP genotyping. Genetic architecture for the kill yield trait showed the presence of 31 SNPs. Three SNPs were found to be the most reliable: BTB-00197584 (p = 7.20 × 10⁻⁵), Hapmap46735-BTA-86653 (p = 5.05 × 10⁻⁵), and BTB-00676077 (p = 7.02 × 10⁻⁵). There were 10 SNPs associated with meat yield. For meat yield, 7 SNPs were identified, four of them exceeding the threshold of established validity: ARS-BFGL-NGS-30557 (p = 1.28 × 10⁻¹²), ARS-BFGL-NGS-68920, ARS-BFGL-NGS-30466 on chromosome 8 (p = 1.20 × 10⁻⁶ and 3.03 × 10⁻⁶, respectively) and ARS-BFGL-NGS-40640 (p = 7.10 × 10⁻⁶). For marbling, 11 SNPs were identified on 6 of 29 chromosomes. These SNPs can act as potential markers for productivity assessment in cattle.

Relevance.On the processes of fermentation in the rumen of ruminants depends, how much final metabolites and their derivatives will be formed, which are necessary for the full development of the body, thehigh level of productivity, those processes also affect the level of formation of endogenous substances, in particular greenhouse gas emissions. These facts lead us to the search for new feed products that improve the metabolic processes in the rumen and the digestive system as a wholePhytochemicals can serve as an alternativeto traditional feed additives. The purpose of the article was to study the effect ofSalviae folia,Scutellaria baicalensis,Origanum vulgareon the formation of methane, the synthesis of volatile fatty acids and nitrogen, as the main indicators of the enzymatic activity of the rumen.Methods.The object of the study was the rumen fluid obtained from bulls of the Kazakh white-headed breed, aged 9–10 months, with an average weight of 225–230 kg (n = 4) with a chronic fistula of the rumen. For the study, a microration was prepared, including 70% of roughage and 30% of concentrated feed as a substrate, and nine prototypes were formed:Salviae folia— 0.8; 1.6; 2.4 g/kg of dry matter (DM),Scutellaria baicalensis— 0.15; 0.2; 0.3 g/kg ofDM,Origanum vulgare— 0.2; 0.3; 0.6 g/kg of DMof ration. The studies were carried out in vitro using the “ANKOM DaisyII” incubator and a specialized technique.Results.It was found that with the use of phytosubstancesSalviae foliaandScutellaria baicalensis, more acetic and propionic acids were formed, and with the use ofOriganum vulgarein various dosages there was a shift towards formation ofpropionic and valeric acids. The formation of a larger amount of microbial protein has been reliably established with the use ofSalviae folia,Scutellaria baicalensis,Origanum vulgarein various dosages. Methanogenesis decreased to a greater extent with the use of higher dosages of phytochemicals, regardless of the source.

The aim of the study was to analyze the effect of a plant feed additive based on Artemisia absinthium and the metal trace element CoCl₂ (cobalt chloride II) on the metabolism of amino acids closely related to the energy of feed and the bacterial community of the rumen of Kazakh white-headed bulls. Animals were divided into four groups: (A)—the control group of animals received the basic diet (BD), (B)—animals of the experimental group I were additionally given A. absinthium at a dose of 2.0 g/kg of dry matter (DM), (C)—II experimental group A. absinthium at a dose of 2.0 g/kg DM with additional CoCl₂ (1.5 mg/kg/DM), and (D)—III experimental group was given only CoCl₂ (1.5 mg/kg/DM) to study the rumen metabolism of amino acids and bacterial diversity of animals, rumen cannula were installed, the experiment was carried out using a 4 × 4 Latin square. It was found that additional feeding of A. absinthium, both separately and in combination with CoCl₂, led to a change in the indices of the alpha biodiversity of the bacterial community. Correlation analysis revealed a linear relationship between the concentration of amino acids and the rumen bacterial community (p ≤ 0.05). The relationship between the values of amino acid concentrations and certain OTUs was established, with a possible percentile probability of 95% for the genera unclassified Lachnospiraceae, unclassified Clostridiales, unclassified Bacteroidales, Fibrobacter, Ihubacter, Phocaeicola, Paludibacter, Akkermansia, Vampirovibrio, unclassified Ruminococcaceae, and Alistipes. Thus, the use of A. absinthium and CoCl₂ as feed additives, both in combination and without, leads to a change in the taxonomic structure affecting the concentration of amino acids. However, further research is needed to better understand the effectiveness and safety of these supplements.

Relevance. By-products of agricultural processing are considered as raw materials for use in animal feed formulations in order to reduce the cost of animal feeding. The inclusion of mineral supplements can increase the nutritional value of diets and allow the use of lower quality feeds.Methods. The object of the study is ruminal digesta from bull-calves with chronic scar fistula, weighing 240–245 kg, 11–12 months old; ultrafine particles (UFP) of zinc (Zn — size 110 nm, Zn 90%). Metabolom was studied on the basis of tests of the following feed samples: sunflower husk subjected to mechanical grinding without treatment and with treatment (hydromodule (water), ultrasonication at 20°С, 15 minutes, 27 kHz). The level of methane was determined on the “Crystallux-2000M” by gas chromatography, the level of volatile fatty acids (VFA) in the contents of the rumen — by gas chromatography on the gas chromatograph “Crystallux-4000M”, determination of nitrogen forms— according to GOST 26180-84.Results. The inclusion of UHF zinc at a dosage of 3.0 mg and 6.0 mg improved the digestibility of DM relative to the control sample by 21.9–22.4% (р ≤ 0.05). The additional inclusion of zinc at a dosage of 1.5 mg and 3 mg contributed to an increase in acetate by 94.7% and 97.9%, propionate —by 85.4% and 71.4% (р ≤ 0.05), butyrate— by 95.6% and 87.3% respectively relative to the control sample. The presence of zinc at a dosage of 6.0 mg significantly increased the concentration of acetate, propionate, butyrate and caproic acid —by 94.9%, 93.2%, 94.4% and 75.4% (р ≤ 0.05) relative to the control. The level of methane formation in all experimental groups relative to the control was significantly lower.