Aug 2026· International Journal of Veterinary Medicine· 0 citations· 16 references
TL;DR
Recommendations are formulated for building a genetic health management system in beef cattle breeding, based on mandatory DNA testing, inbreeding control, accounting for pleiotropic effects in selection, and the integration of advanced biotechnologies.
Abstract
The review article presents a comprehensive analysis of current data on hereditary anomalies in beef cattle breeds, including hypotrichosis (HY), dilutor (DL), idiopathic epilepsy (IE), mandibulofacial dysplasia (MD), and maple syrup urine disease (MSUD). The results of genomic studies that identified key mutations (in the KRT71, PMEL, CYP26C1, BCKDHA/BCKDHB genes) and their pleiotropic effects, impacting both phenotype and productive qualities of the animals, are summarized. Particular attention is paid to the differences in the prevalence of genetic defects in cattle across various countries, which is associated with the intensity of selection, the level of inbreeding, and the effectiveness of genetic monitoring programs. Using the example of the genetic anomaly causing maple syrup urine disease (MSUD) in animals, promising therapeutic strategies are considered—from conservative metabolic control to innovative approaches using AAV vector-based gene therapy and in vitro base editing. The commonality of molecular mechanisms of hereditary diseases in humans and farm animals is emphasized, opening opportunities for translational research. Recommendations are formulated for building a genetic health management system in beef cattle breeding, based on mandatory DNA testing, inbreeding control, accounting for pleiotropic effects in selection, and the integration of advanced biotechnologies. The work is of interest to specialists in the field of veterinary genetics, breeding, and biotechnology.
Kazakhstan ruminant genomics is expanding through targeted diagnostic testing, SNP-array studies, whole-genome sequencing, runs of homozygosity, candidate-gene analyses, transcriptomic studies and pathogen molecular diagnostics. However, these evidence types differ substantially in their relevance for breeding decisions. This structured narrative review evaluates molecular evidence for inherited disorders, deleterious alleles, disease-resistance loci, reproductive genes and genomic-health indicators in Kazakhstan cattle, sheep and goats. We define actionable evidence as evidence that can directly inform breeding management because it involves a validated pathogenic variant, risk variant or fertility haplotype detected or excluded in breeding-relevant animals or germplasm. Under this definition, cattle currently provide the strongest immediately actionable evidence, mainly because targeted studies have screened validated defects and fertility-related loci in artificial-insemination bulls, imported germplasm or breed-relevant populations. Evidence includes Kazakhstan-associated screening for BLAD (Bovine leukocyte adhesion deficiency), DUMPS (Deficiency of uridine monophosphate synthase), hypotrichosis, OH1-associated achromatopsia, fertility haplotypes and several beef- or dairy-breed recessive defects. In sheep, evidence is broader but less directly actionable, consisting mainly of prion protein gene preparedness, MHC (Major histocompatibility complex)-related immune hypotheses, reproductive candidate loci, runs of homozygosity, genome wide associated data and pathogen-exposure context. In goats, current evidence is mostly population-genomic and adaptation-oriented, while hereditary-disease surveillance and phenotype-linked resistance studies remain sparse. We propose an author-defined staged genomic-health framework that separates validated carrier-screening evidence from candidate genomic signals and international evidence requiring local validation. Priority actions include carrier-aware management of high-impact cattle germplasm, representative prion protein gene and runs of homozygosity baselines in small ruminants, phenotype-first surveillance, biobanking and national genotype–phenotype databases.
A. Mussayeva, N. Malmakov, Berik Aringaziev et al.· International Journal of Mol...· 0 citations
The article presents the results of a study on the combined genotypes of
OPN
(c.8514C/T) and
IGF-1
(512T/C) genes in a population of Holstein heifers (n=202). The experiment was conducted at the Lenin Breeding Farm (Atninsky District, Republic of Tatarstan), and laboratory analyses were carried out at the Tatar Research Institute of Agriculture, Kazan Scientific Center of the Russian Academy of Sciences. The relevance of the study is driven by the need to identify genetic markers associated with reproductive traits in cattle, as fertility indicators alongside milk productivity determine the economic efficiency of dairy farming. The
OPN
and
IGF-1
genes are involved in the regulation of embryogenesis, implantation, folliculogenesis, and early embryonic development; however, their combined interaction remains insufficiently studied. Genotyping was performed using PCR-RFLP with restriction endonucleases
BseI
(for
OPN
) and
BstSNI
(for
IGF-1
). The analysis revealed the presence of all nine possible combined genotype combinations, confirming the genetic heterogeneity of the studied population. The highest frequency was observed for the combined genotype CT/AB (29.7%), while the lowest frequencies were found for CC/BB (2.0%) and CC/AA (3.0%) by
OPN
/
IGF-1
. A pattern of decreasing frequency of combined genotypes was established with an increasing number of homozygous loci. Comparison of the observed and theoretically expected distributions showed no statistically significant deviations (χ² = 4.67; p > 0.05), indicating independent allele combination of the studied genes and the absence of factors disrupting genetic equilibrium in the sample. The obtained data can be applied in breeding programs for marker-assisted selection of parental pairs, genetic passportization, and monitoring of the genetic structure of cattle populations.
N. Safina, E. Mukhanina, E. R. Gainutdinova· Legal regulation in veterina...· 0 citations
One of the most important agricultural industries in the world is sheep (
Ovis aries
), considering essential resources such as meat, milk, and wool. Genetic and genomics innovations have significantly improved the efficiency and sustainability of sheep production, which requires a thorough knowledge of the genetic basis of economically relevant traits that are controlled. This is a comprehensive review of the historical development of sheep genetics, from basic stages in the use of microsatellite markers in linkage mapping to the current environment of high-throughput genotyping methods, whole-genome sequencing, and GS (Genomic Selection), which collectively form the basis of contemporary improvement programs. The review is organized by major trait categories, which include growth and body composition, reproduction and fertility, wool quality, and disease resistance. The major genes and QTL (Quantitative trait loci) of each category are defined and described, as well as their biological roles, molecular mechanisms, and their usage in modern breeding solutions are discussed. The most important methodologies that enable these discoveries are elucidated, including linkage analysis, GWAS (Genome-wide association studies), RNA-sequencing (RNA-Seq), and newly emerging multi-omics approaches. Comparative studies also show that there are conserved genetic processes and structures in various sheep breeds and other livestock species, specifically cattle, which indicates species-specific and common regulatory pathways. Rather than claiming to be an exhaustive historical record, this narrative review synthesizes major advances in sheep genetic mapping, functional genomics, and GS relevant to economically important traits. By critically evaluating the strength of evidence, mapping resolution, and practical breeding applications, this work aims to provide researchers, breeders, and students with a balanced, evidence-based resource to guide future genomic improvements in sustainable sheep production.
Mostafa Ghaderi-Zefrehei, Effat Nasre Esfahani, Hassan Amini Pozveh et al.· Frontiers in Genetics· 0 citations
INTRODUCTION
Suckler cow farming is a key part of Swiss beef production, representing extensive farming practices and high standards of animal welfare. Around 7 % of the country's cattle are registered with the relevant breeding association. Switzerland boasts a high degree of genetic diversity, with 38 beef and dual-purpose breeds. This study aimed to systematically catalogue known recessive genetic defects and selected inherited traits of the most common Swiss suckler cow breeds and determine their prevalence. Worldwide, 67 monogenic recessive genetic defects have been identified in beef cattle. Of these, 42 - caused by 45 known gene variants - affect the ten most commonly kept suckler cow breeds in Switzerland. Currently, 40 causative gene variants for 37 genetic defects are routinely tested in Switzerland. No carrier animals have yet been identified for 13 of these variants. In contrast, heterozygous carriers were rarely identified for a total of 27 variants. The breed-specific allele frequencies exceeded 1 % for 14 harmful alleles. The causal variant for retinitis pigmentosa 1 was particularly widespread in Charolais and Angus cattle, as was the causal variant for developmental duplication in Angus cattle. Additionally, single homozygous affected animals were confirmed for the first time in Switzerland: tibial hemimelia in Galloway cattle and progressive ataxia in Charolais cattle. In addition to genetic defects, breeding-relevant monogenic traits such as muscle hypertrophy and hornlessness are also examined. These traits sometimes occur with high allele frequencies in several breeds and can therefore be targeted specifically in breeding programs. SWISScow SNP array genotyping enables harmful recessive alleles to be monitored. Suspected cases should be reported and investigated. Digital breeding planning tools help to avoid risk matings of heterozygous carriers, thereby reducing reproductive losses and improving animal health and welfare in the long term.
M. Burren, F. Seefried, M. Meylan et al.· Schweizer Archiv für Tierhei...· 0 citations
The Brown Swiss (BS) cattle breed is one of the major Swiss dairy breeds. Intensive selection and the widespread use of few elite sires in artificial insemination have increased inbreeding and the occurrence of deleterious recessive alleles in the homozygous state. Analyzing life trajectories in large, genotyped cohorts can identify hidden recessive disorders that are difficult to detect using traditional case-control association testing. Long-read DNA sequencing enables precise detection of causal alleles, including structural variants. This study aimed to (1) identify cryptic recessive loci affecting rearing performance in Swiss BS cattle, (2) evaluate their impact on survival, (3) characterize the associated phenotype, (4) identify the causal variant using long-read whole-genome sequencing, and (5) assess its functional impact. Using Homozygous Haplotype Enrichment/Depletion (HHED) mapping, we identified a risk haplotype (BH39) on chromosome 15 spanning from 16,276,819 bp to 16,446,984 bp that was associated with increased juvenile mortality within the first 180 days of life when present in the homozygous state. The BH39 occurred at a frequency of approximately 4.5% in Swiss BS cattle and 5.3% in German and Austrian BS cattle, and homozygous carriers exhibited a significantly reduced first-year survival rate. Five females homozygous for BH39 underwent clinical examination. They all showed recurrent respiratory disease, impaired growth, poor body condition, rough hair coat, and brown-discolored teeth. Pathological examination revealed bronchopneumonia and eosinophilic enteritis. Clinicopathological findings indicated failure to thrive and immunodeficiency. Long-read WGS of two BH39 homozygous calves revealed a private homozygous coding variant that was in high linkage disequilibrium with BH39. The identified structural variant was an insertion of a large transposable element (10.4 kb ERVK[2-1-LTR]) into the third exon of ALKBH8 (NM_001080341.2 c.267_268indel). Full-length RNA sequencing of cerebellum and liver from a homozygous calf revealed that the endogenous retrovirus (ERV) insertion introduces a cryptic transcription termination signal, truncating ALKBH8 mRNA. This study demonstrates that exploring population-scale genomic data and mining thousands of life-history records, followed by veterinary follow-up evaluations and molecular genetic analyses, provides an effective strategy for identifying cryptic recessive disorders that shorten the lifespan of cattle. The findings provide strong evidence that the ERV insertion into the coding sequence of ALKBH8 represents a loss-of-function variant that causes a previously undescribed recessive disorder that results in increased rearing loss. Interpretive summary We identified a recessive disorder in Brown Swiss cattle that causes retarded growth, recurrent infections, immunodeficiency, and increased mortality during the first year of life. Using population-scale genomic data, clinical investigations, and long-read sequencing, we linked the disorder to an exonic transposable element insertion disrupting ALKBH8. The identification of the causal variant now enables direct genetic testing and the implementation of genome-based mating strategies to avoid carrier-by-carrier matings and, consequently, prevent the birth of affected homozygous offspring. We demonstrate the utility of integrating large-scale breeding records, veterinary phenotyping, and advanced genomics to identify hidden defects affecting livestock health and productivity.
S. Glatthard, N. Kadri, F. Seefried et al.· bioRxiv· 0 citations
Relevance.
Small Ruminant Lentiviruses (SRLVs), including the Visna-Maedi Virus (VMV) in sheep, induce chronic progressive inflammation primarily targeting the nervous system, lungs, mammary glands, and joints. These viruses exhibit significant genetic variability, leading to a lack of effective therapies or vaccines at an affordable cost. Foreign research has identified breed-specific variations in genetic resistance to these pathogens, but such comparative data remain largely unexplored for Russian sheep breeds. A reliable DNA marker of genetic resistance to VMV infection is the ovine transmembrane protein 154 (TMEM154) gene. This study aimed to evaluate the allelic diversity among different Russian sheep breeds through targeted SNP within the TMEM154 gene linked to genetic resistance.
Methods.
The study utilized biological samples (tissues) of sheep maintained at the Ladozhsky PZ and from the biobank repository titled “Genetic Materials Bank of Domestic and Wild Animals.” To identify specific mutations correlated with resistance to VMV, fragments encompassing the target SNP (OAR17_5388531) within the TMEM154 gene were amplified via RT-PCR.
Results.
Analysis of TMEM154 polymorphisms uncovered two distinct alleles (C and T) along with their corresponding genotypes: TT, CT, and CC. Genotype distributions associated with resistance to the Visna-Maedi virus across eighteen diverse Russian sheep breeds have been documented.
O. S. Yakovleva, T. Deniskova, O. Koshkina et al.· Agrarian science· 0 citations
A new method for surgically removing training examples from a model reveals that as datasets grow, the link between what a model learns and what it produces dissolves.
MIT News · Artificial Intelligence· news.mit.eduAug 17, 2026
