This study conducted a comparative analysis of the species composition, morphometric characteristics, and abundance of rumen ciliate protozoa in three cattle breeds: Yakutian aboriginal, Simmental, and crossbred. Rumen samples were collected via esophageal probe, fixed in 4% or 10% formalin, and analyzed within 6 hours. Ciliate abundance ranged from 535 to 26,500 individuals/mL, influenced by season and feeding type (roughage for Yakutian cattle, mixed rations for Simmental and crossbred). Bacterial concentrations ranged from 100 million to 10 billion/mL. The highest species diversity (36 species, 12 genera) was observed in Yakutian cattle, including 13 breed -specific species, such as the rare Charonina ventriculi and a previously undescribed Metadinium sp., likely due to adaptation to coarse feed and the cow-calf housing system. Simmental cattle exhibited two specific species, while crossbred cattle lacked specific species. Morphometric analysis revealed significant differences in cell sizes among breeds (p<0.001), with Metadinium medium being the largest ciliate (up to 224.2 µm in length) and Entodinium exiguum the smallest (28.3–36.4 µm). Faunal comparisons using the Jaccard-Malyshev coefficient (Kj– m = 0.67) and the Chekanovsky-Sørensen index (Ics = 40%) indicated the greatest differences between Yakutian and Simmental cattle. Probiotic transplantation (biomass with > < 0.001), with Metadinium medium being the largest ciliate (up to 224.2 µm in length) and Entodinium exiguum the smallest (28.3–36.4 µm). Faunal comparisons using the Jaccard-Malyshev coefficient (Kj– m = 0.67) and the Chekanovsky-Sørensen index (Ics = 40%) indicated the greatest differences between Yakutian and Simmental cattle. Probiotic transplantation (biomass with >5,000 ciliates/mL) from healthy Yakutian donors to three Holstein heifers confirmed the method’s efficacy in normalizing digestion, restoring microbiota postantibiotic therapy, preventing gastrointestinal disorders, enhancing feed digestibility, and improving productivity. The method reduced diarrheal episodes and improved nitrogen balance, highlighting its potential in cattle farming.
The biological characteristics of pathogenic Brucella strains in various animal species are the most important factor in the fight against this disease. The results of studying Brucella cultures are crucial for the development of specific prevention and diagnosis methods. The use of control strains of B. melitensis 16M and B. suis 1330 at a concentration of 10 m.c. resulted in the development of extensive generalized disease in infected animals. While B.abortus 183 became more pathogenic when used at 50 m.c. and caused widespread infectious lesions, especially at high doses. In the study of the pathogenicity of the "deer" strain 010 in cattle, pigs, and sheep, it was found that its virulence is lower than that of B.abortus 183 and B.suis 1330. Isolated from wild and economically -maintained populations of reindeer in the republic, Brucella strains retain stability and the resulting uniformity of phenotypic characteristics. A typical picture for the hemoculture: in comparison with other Brucella serovarieties, these isolates demonstrate pronounced virulence and tropism to Rangifer tarandus , whereas Sus scrofa , Bos taurus , and Ovis aries , on the contrary, show high species-specific resistance both in laboratory infection and in natural biogeocenoses. Epizootiological monitoring has confirmed the autonomy of brucellosis foci in Yakutia, which indicates a unique epidemic and epizootic situation that is specific to this region.
Relevance . In the conditions of the Republic of Sakha (Yakutia), the deficit of high-protein feeds limits livestock productivity. The cultivation of maize on permafrost-affected soils requires the development of effective agronomic practices, including the combined use of mineral fertilizers and biological preparations. Methods . The research was conducted in 2024-2025 on permafrost-affected sod-meadow soil at the Yakutsk Research Institute of Agriculture. The experimental scheme included 9 treatments: control, N 60 P 60 K 60 , N 90 P 90 K 90 , biological preparations «Fito Nord — Bakt» and «Mamontenok» (Bacillus subtilis strains), as well as their combinations with fertilizers against a background of row spacings of 30 and 60 cm. Yield, chemical composition (using an infrared analyzer Spectra Star 2200), and economic efficiency were determined. Results . The highest green mass yield of maize (38.9 t/ha at 30 cm row spacing and 38.6 t/ha at 60 cm row spacing) was obtained with the combined application of N90P90K90 and the biological preparation «Mamontenok». The crude protein content reached 22.122.4%, which is significantly higher than the control. The use of biological preparations improved biometric parameters and plant resistance to stressful weather conditions (en dash: HTC 0.3–0.7). Economic assessment showed a profitability of up to 90% (N 90 P 90 K 90 + + «Mamontenok» treatment, 60 cm row spacing) with a conditional net income of 36 586 rubles/ha. Wide-row sowing (60 cm) provided better plant access to light and heat. The integrated application of N 90 P 90 K 90 and the biological preparation «Mamontenok» is an economically sound and highly profitable technique for maize cultivation in the permafrost zone of Yakutia.
Brucellosis among farm animals is a serious problem for veterinary science and practice. This disease is a danger to human health and is widespread in disadvantaged regions of Russia. Many years of experience in combating brucellosis in reindeer, including organizational, economic, veterinary and sanitary measures, have shown their insufficient effectiveness. The problem is compounded by the presence of natural foci of infection in wild reindeer. In recent years, considerable attention has been paid to the development of new diagnostic methods that distinguish post-vaccination brucellosis antibodies from antibodies caused by spontaneous infection. The immunodiffusion reaction with polysaccharide antigen in other types of farm animals is successfully used as a differential test. Production experiments have shown that this reaction is highly specific and identifies animals with high rates of the agglutination reaction and complement binding reaction. The immunodiffusion reaction becomes positive 1-3 weeks after infection and remains positive until the end of the follow-up period in all infected reindeer. Studies in farms with vaccinated reindeer affected by brucellosis have shown that the immunodiffusion reaction is a specific reaction, but its sensitivity is inferior to the agglutination reaction+complement binding reaction complex. The use of the immunodiffusion reaction in combination with the agglutination reaction and complement binding reaction, as well as specific prophylaxis using vaccines from B. abortus strains 19 and 82, makes it possible to reduce the intensity of the epizootic process and create prerequisites for the improvement of herds within 20-24 months.
The advancement of dairy farming hinges significantly on establishing a robust forage foundation alongside employing breeds of cattle with high productivity. In autumn 2013, 150 Red Steppe heifers were transferred from Altai Territory to OOO Byan in Ust-Aldan District. This breed is recognized for its substantial genetic capacity for milk production; under optimal management, yields range from 3,000 to 6,000 kg per lactation. Yakutia’s harsh climatic contrast—with severe winters, notably low temperatures, and brief summers—poses challenges for producing adequate high-quality fodder compared to Altai. In 2015, a study was executed on first-calf Red Steppe heifers, comparing dietary impacts on milk output. The experimental group's diet incorporated 5.0 kg of mixed grass hay, 4.3 kg of seeded cereal hay, 15.0 kg of fresh oats, 2.0 kg of dried brewer's grains, and 2.0 kg of local feed enhanced with 300 g of Felutsen daily, totaling 118.0 MJ of metabolizable energy and 14.4 kg of total dry matter. The control group’s feed lacked the brewer's grains and Felutsen supplement. Results demonstrated a superior milk yield by 18.9% in the experimental group. Highlighting the diet’s effectiveness, the inclusion of 13% dried brewer's grains and 17% Felutsen-fortified feed proved financially beneficial, generating an additional income of 52,138.0 rubles with a 10.0% profit margin in milk production. This study aimed to evaluate the implications of enriching cattle diets with energy-protein-mineral supplements on the lactational performance of first-calf heifers under northern environmental conditions.
