In beef cattle breeding, genome-wide association studies (GWAS) using single nucleotide polymorphisms (SNPs) arrays can reveal many loci of various production traits, such as growth, productivity, and meat quality. With the development of genome sequencing technologies, new opportunities are opening up for more accurate identification of areas associated with these traits. This article aims to develop a novel approach to the lifetime evaluation of cattle by 3-D visualization of economic-biological and genetic features. The purpose of this study was to identify significant variants underlying differences in the qualitative characteristics of meat, using imputed data on the sequence of the entire genome. Samples of biomaterial of young Aberdeen-Angus breed cattle (n = 96) were the material for carrying out genome-wide SNP genotyping. Genotyping was performed using a high-density DNA chip Bovine GPU HD BeadChip (Illumina Inc., San Diego, CA, USA), containing ~150 thousand SNPs. The following indicators were selected as phenotypic features: chest width and chest girth retrieved by 3-D model and meat output on the bones. Correlation analysis showed a reliable positive relationship between chest width and meat output on the bones, which can potentially be used for lifetime evaluation of meat productivity of animals.

Coumarins are class of natural aromatic compounds based on benzopyrones (2H-1-benzopyran-2-ones). They are identified as secondary metabolites in about 150 different plant species. The ability of coumarins to inhibit cell-to-cell communication in bacterial communities (quorum sensing; QS) has been previously described. Coumarin and its derivatives in plant extracts are often found together with other small molecules that show anti-QS properties too. The aim of this study was to find the most effective combinations of coumarins and small plant-derived molecules identified in various plants extracts that inhibit QS in Chromobacterium violaceum ATCC 31532 violacein production bioassay. The coumarin and its derivatives: 7-hydroxycoumarin, 7.8-dihydroxy-4-methylcoumarin, were included in the study. Combinations of coumarins with gamma-octalactone, 4-hexyl-1.3-benzenediol, 3.4.5-trimethoxyphenol and vanillin, previously identified in oak bark (Quercus cortex), and eucalyptus leaves (Eucalyptus viminalis) extracts, were analyzed in a bioassay. When testing two-component compositions, it was shown that 7.8-dihydroxy-4-methylcoumarin, 4-hexyl-1.3-benzendiol, and gamma-octalactone showed a supra-additive anti-QS effect. Combinations of all three molecules resulted in a three- to five-fold reduction in the concentration of each compound needed to achieve EC₅₀ (half maximal effective concentration) against QS in C. violaceum ATCC 31532.

A large number of cattle breeds have marked phenotypic differences. They are valuable models for studying genome evolution. ROH analysis can facilitate the discovery of genomic regions that may explain phenotypic differences between breeds affecting traits of economic importance. This paper investigates genome-wide ROH of 189 Aberdeen Angus bulls using the Illumina Bovine GGP HD Beadchip150K to structurally and functionally annotate genes located within or in close ROH of the Aberdeen Angus cattle genome. The method of sequential SNP detection was used to determine the ROH. Based on this parameter, two ROH classes were allocated. The total length of all ROH islands was 11,493 Mb. As a result of studying the genomic architecture of the experimental population of Aberdeen Angus bulls, nine ROH islands and 255 SNPs were identified. Thirteen of these overlapped with regions bearing ‘selection imprints’ previously identified in other breeds of cattle, and five of these regions were identified in other Aberdeen Angus populations. The total length of the ROH islands was 11,493 Mb. The size of individual islands ranged from 0.038 to 1.812 Mb. Structural annotation showed the presence of 87 genes within the identified ROH islets.

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.

In the poultry industry, feed additives with positive effects on the condition of the poultry are constantly used. Antimicrobials are used for this purpose. However, the indiscriminate use of antibiotics accelerates the spread of antibiotic resistance among bacteria. Hence, researchers have increased interest in finding alternative feed additives. Plant extracts are of considerable interest in this matter as they have a wide range of biological properties including antibacterial activity. Phytobiotics, have been found to increase productivity, feed conversion ratio, safety and meat quality. Among the potential phytobiotics, oak bark extract (Quercus cortex) should be emphasized, the activity of which is associated with the content of more active substances. With this in mind, the purpose of this work was formulated to study the effect of Quercus cortex extract and the feed antibiotic Biovit 200 based on 20% chlorotetracycline on feed digestibility, its slaughter properties and the content of chemicals in the body of broilers.The results obtained during the study suggest that the use of Quercus cortex extract (at a dose of 0,2 ml/kg) both alone and in combination with Biovit 200 (at a dose of 0,63 g/kg w.m./day contributed to an increase in the EIP index, digestibility coefficients. An excess in slaughter yield in I, II and III groups over the control group was recorded.

Relevance. Nutrients in feed affect animal maintenance, growth and reproduction. Deficiencies of essential nutrients in feed are usually compensated by additives. Among such additives, proteases are widely used. Proteases facilitate more efficient breakdown of feed proteins into amino acids that are then easily digested by the body, which is especially important for young animals that need sufficient amino acids to support intensive growth. Optimising amino acid digestion by proteases can lead to improved feed utilisation efficiency, increased weight gains and better overall health of steers. In addition, it may reduce dependence on expensive protein supplements in the diet.The aim of the study was to study the peculiarities of amino acid absorption by bullheads when protease is included in the diet.Materials and methods. Objects of the study: rumen fluid (RF), chyme and faeces of steers of the Kazakh white-headed breed.Results. Analysis of the results showed that the introduction of proteases (fungal and bacterial) promotes better absorption of amino acids in the body of bulls. Bacterial protease (group II) showed the greatest activity, which is confirmed by the data of increase in assimilation of lysine (by 12,5%), phenylalanine (by 12,3%), tyrosine (by 9,2%), serine (by 8,9%), threonine (by 8,8%), alanine (by 8,1%), isoleucine and glycine (by 7,6%), valine (by 5,9%), proline (by 2,3%) and arginine (by 2,9%), relative to the control group.