In this study, we evaluated the progeny quality of proven bulls of the Aberdeen Angus breed in different selections. Reliable information about the productive qualities of the daughters and cows of proven bulls is limited in Kazakhstan’s scientific literature. We aimed to identify bull-improvers by comparatively evaluating cows of different genotypes in terms of productive qualities. The study was conducted in the period of 2021–2023, during which four groups of cows were formed based on origin. In conclusion, the high influence of inheritance of breeding features from bull-improvers should be highlighted: 78.6% to the daughters of cows of group I (Estonian selection from Kolos-firma LLP: EE 14465116 ABAJA PORTOS 95283, DK 1989501341 FREDERIK 95220, and EE 16966079 ABAJA PATRICK 95305) and 74.5% to the daughters of cows of group III (Canadian selection from Vishnevskoe LLP: BH BRUIN 54X 1644270 and JL DISTRICT 0311 1594050). There was less influence from proven bulls of deteriorators of the Kazakh selection: 21.4% to the daughters of cows of group II from Kolos-firma LLP (KZP156547191) and 25.5% to the daughters of cows of group IV from Vishnevskoe LLP (Henri KZT157789649 and Argus KZT155778964). Therefore, it is recommended that valuable genotypes of imported selection are used in breeding work in the Kostanay and North Kazakhstan regions for the improvement of Aberdeen Angus cattle.

This article presents the findings of a scientific study investigating the efficacy of various assessment techniques used to evaluate the adaptability and productive qualities of Aberdeen Angus cattle on three prominent farms in the northern region of the Republic of Kazakhstan. A comprehensive analysis of the haematological and biochemical parameters of experimental groups of cattle with different genotypes (American, Canadian, and Estonian selection) was conducted. The studies revealed notable variability in haematological and biochemical indicators, contingent on the origin. Concurrently, the dynamics of the aforementioned indicators did not exceed the physiological norms. The modern allelofund was characterised with the help of microsatellite markers, and the level of genetic diversity of Aberdeen Angus cattle of different genotypes was estimated. The research uncovered the genealogical structure of the populations, the purity of the populations, the provenance, the polymorphism level, the heterozygosity indices, and the Wright fixation index (Fis). The genotyping of cattle of the Aberdeen Angus breed on 15 microsatellite markers yielded the establishment of 80 alleles in the Kolos-firm LLP, 77 alleles in the Vishnevskoe LLP, and 92 alleles in the Sever-Agro N LLP. The total expected heterozygosity was He = 0.673, while the observed heterozygosity was Ho = 0.710.

Background: A total of 396 samples were taken from the hearts, oesophagi, and diaphragms of 132 horses slaughtered at slaughterhouses in 2023 for subsequent examination. Methods: The histological method revealed pathomorphological changes in the muscle tissue. The molecular method identified the pathogen species. Results: Histological examination revealed thick-walled cysts with internal septa and numerous bradyzoites, and mononuclear inflammatory cells with pericyst infiltrates. Microcyst samples were amplified by polymerase chain reaction. Molecular genetic analysis allowed for the identification of 18 sarcocysts. Phylogenetic analysis of Sarcocystis isolates revealed three separate clades of Sarcocystis bertrami and two separate clades of Sarcocystis fayeri. Comparison and phylogenetic analysis revealed a very close relationship between the identified Sarcocystis species and other equine Sarcocystis DNA sequences from China and Japan. Based on the results obtained, the epizootic situation and the parasitic level of sarcocystosis contamination of horses in the northern Kazakhstan were determined. Conclusion: This is the first histological and molecular study to identify Sarcocystis spp. isolated from microscopic forms of equine sarcocysts in the northern Kazakhstan. This research will contribute to the fight against the spread of sarcocystosis in the Republic of Kazakhstan and will allow us to develop proposals for improving the mechanisms of sarcocystosis control.

Staphylococcus aureus is a leading cause of foodborne illness in animal-derived food products, yet comprehensive data on its antimicrobial resistance and toxigenic potential from Central Asia remain scarce. We examined 711 food samples (meat, milk, and dairy products) from the Kostanay region of Kazakhstan (2024–2025). Isolates were identified by MALDI-TOF mass spectrometry; antimicrobial susceptibility was assessed by disk diffusion (EUCAST v.16.0); enterotoxin production (types A–E) by ELISA; and resistance and toxin genes by PCR. Concordance between methods was evaluated using Cohen’s kappa coefficient. S. aureus was recovered from 11.8% of samples (84/711), with raw cow’s milk carrying the highest contamination risk (OR = 2.75; 95% CI: 1.74–4.38). High resistance to ampicillin (52.4%) and benzylpenicillin (50.0%) was found; 20.2% of strains were multidrug-resistant. Among the 17 cefoxitin-resistant isolates, only 4 harbored mecA, suggesting that 13 isolates (15.5%) should be interpreted as cefoxitin-resistant, mecA-negative isolates with a putative BORSA-like phenotype rather than as confirmed MRSA. Staphylococcal enterotoxins A–E were detected in 26.2% of isolates, and egc-cluster genes seg and sei were present in 9.5% each. The strongest genotype–phenotype concordance was observed for aph(3′)/kanamycin (κ = 0.65) and blaZ/benzylpenicillin (κ = 0.64). These results underscore the need for combined molecular and phenotypic surveillance for regional food safety monitoring.

Background and Aim: Listeria monocytogenes remains a major foodborne pathogen globally, with mortality rates ranging from 20%–40%. The increasing incidence of listeriosis and the limitations of culture-based and polymerase chain reaction-based diagnostics highlight the need for rapid, cost-effective, and highly specific immunoassays. This study aimed to develop and validate a regionally adapted sandwich enzyme-linked immunosorbent assay (ELISA) based on monoclonal and polyclonal antibodies (pAbs) raised against a recombinant p60 antigen derived from a Kazakhstani L. monocytogenes field isolate. Materials and Methods: The p60 gene lacking its N-terminal signal peptide was amplified from a regional L. monocytogenes isolate, cloned into the pET28c(+) vector, and expressed in Escherichia coli arctic express (DE3). Recombinant p60 protein was purified by Ni2⁺-affinity chromatography and used to immunize BALB/c mice and Chinchilla rabbits for monoclonal antibodies and pAbs antibody production. Hybridoma clones were screened for specificity using indirect ELISA and Western blot. A sandwich ELISA was assembled using mAb 1H8 as the capture antibody and horseradish peroxidase-conjugated rabbit pAbs as detection antibodies. Analytical sensitivity and diagnostic performance were evaluated using serial dilutions of recombinant p60 and culture supernatants of L. monocytogenes isolates recovered from 507 food samples. Results: The recombinant p60 antigen (50.3 kDa) was successfully expressed and purified at 5.9 mg/L yield. Among seven stable hybridoma clones, mAb 1H8 exhibited the highest affinity (Ka = 2.5 × 1010 M⁻1) and specificity without cross-reactivity to non-Listeria bacteria. The optimized sandwich ELISA achieved a detection limit of 1.5 ng/mL, corresponding to approximately 103 colony-forming units/mL. All six L. monocytogenes field isolates tested positive in the assay, with results strongly correlating with viable cell counts (R2 = 0.89). The assay demonstrated comparable sensitivity to commercial kits while offering shorter assay time (2 h) and substantially lower production cost. Conclusion: The developed sandwich ELISA provides a sensitive, specific, rapid, and regionally tailored diagnostic platform for detecting pathogenic L. monocytogenes in food samples. By integrating locally produced recombinant antigens and immunoreagents, the assay offers a cost-effective alternative to imported kits, supporting national food safety programs and One Health surveillance initiatives. Keywords: food safety surveillance, foodborne pathogens, hybridoma technology, immunodiagnostics, Listeria monocytogenes, monoclonal antibodies, One Health, p60 antigen, polyclonal antibodies, recombinant protein, sandwich enzyme-linked immunosorbent assay.

The widespread use of antibacterial agents in livestock production is associated with antibiotic residues in animal products and feed, posing a potential threat to food safety and contributing to antimicrobial resistance. The aim of this study was to assess contamination levels of beef, pork, and feed with antibiotic residues in the Kostanay region. The results demonstrated the presence of antibiotic residues in beef, pork, and feed, while all detected concentrations remained below established maximum residue limits. Despite compliance with regulatory standards, residues were detected frequently, and their levels differed significantly depending on feed type (p < 0.001). Microbiological analysis confirmed the presence of Escherichia coli and Staphylococcus aureus in meat samples, with isolates exhibiting moderate to high antimicrobial resistance, particularly in pork. The highest resistance was observed to tetracycline, streptomycin, and thiamphenicol. The obtained data indicate that even trace antibiotic concentrations entering the “feed–animal–product” chain may be associated with selective pressure on microbiota and the circulation of resistant microorganisms. The results highlight the need for comprehensive monitoring of feed and animal products to assess and mitigate antimicrobial resistance spread within the food chain.