Kazakh horses represent an important cultural heritage of the Kazakh people, shaped over thousands of years across the territory of present-day Kazakhstan. Long-term adaptation to extreme natural conditions has led to the development of a unique set of characteristics that ensure the high survivability, ecological plasticity and economic value of these horses. Long- and short-read sequencing was performed for three breeds (Adai, Zhabe, Mugalzhar), while Naiman was sequenced exclusively with nanopore long-read data. The resulting reads were assembled, and the genomes were subsequently annotated. The assembled genomes showed high contiguity with an average contig N50 value of 9.68 Mb (9,681,711 bp) for Adai, Zhabe and Mugalzhar, while the resulting contig N50 was 17.09 Mb (17,090,216 bp) for Naiman, and average assembly length was 2.42 Gb (2,442,471,376 bp). These are individual reference assemblies that establish foundations for future comparative genomics and pangenome development. Gene annotation yielded 19,584, 19,941, 18,695 and 20,572 protein-coding genes for Adai, Zhabe, Mugalzhar and Naiman, respectively. These assemblies complement existing assemblies for future genetic analysis, research into the geographic and breed origins of domestic horses, and breed conservation efforts, and will contribute to ongoing equine pangenome efforts.

Agricultural lands in East Kazakhstan region cover a significant area, with large portions of pasture and cropland situated in close proximity to operating industrial facilities. Despite this, no comprehensive integrated assessment combining remote sensing, ground-based soil monitoring, and flora survey had previously been conducted for the zone of influence of the Nikolaevskaya enrichment plant. This study aimed to fill that gap by a 40-year land cover analysis (1985-2024) using publicly available satellite data processed in Google Earth Engine with soil sampling and vegetation surveys across 17 sites. Soil analyses revealed not only elevated heavy metal concentrations but also a sharp pH decrease, conditions under which heavy metals become significantly more mobile and available for plant uptake. Technosol formation was observed at multiple sampling points, indicating a permanent transformation of the natural soil profile. The flora survey recorded 72 species from 62 genera, with ruderal and synanthropic species domina-ting disturbed habitats and native species persisting only at control points more distant from the facility. Taken together, these findings point to ongoing ecosystem degradation and raise concrete concerns for the regional food chain given the pastureland and cropland adjacent to the plant.

The Mugalzhar horse is an important native breed of Kazakhstan, valued for its adaptability, milk production, and meat productivity under extensive pasture-based management. This study evaluated the relationships among first-lactation milk yield, productive longevity, lifetime milk production, growth, morphometric traits, and milk composition in the Mugalzhar horse breed using data from 100 mares with complete lifetime production records, 108 adult mares and 12 stallions for morphometric evaluation, and 68 foals (35 colts and 33 fillies) for growth analysis. The study was conducted on Mugalzhar horses maintained at the “Senim” farm in the Turkestan region of Kazakhstan. Morphometric measurements of adult horses, growth dynamics of foals from birth to 18 months of age, milk productivity records, productive longevity indicators, and milk composition data were analyzed. PCA, Pearson correlation analysis, and HCA were applied to assess relationships among productive and compositional traits. Adult stallions and mares closely conformed to breed standards, with stallions exceeding mares by approximately 7.8% in live weight. Foals exhibited intensive postnatal growth, with live weight increasing 6.8–6.9-fold between birth and 18 months of age. Milk yield increased from 722.3 kg during the first lactation to 986.9 kg during the fifth lactation before declining in later lactations, whereas milk composition remained relatively stable. Moderate-to-high first-lactation milk yield groups (G3–G4) achieved the greatest lifetime milk production (24,961–25,997 kg), longest productive life (7.9–8.5 years), and highest number of completed lactations (6.6–6.9). PCA revealed two major biological gradients representing productivity and longevity, while HCA identified G3–G4 as the most favorable production cluster. Milk fat and protein concentrations were negatively associated with milk yield traits. Moderate first-lactation milk yield was associated with the greatest lifetime productivity and longest productive herd life, whereas extremely high first-lactation milk yield was not associated with superior lifetime performance. These findings suggest that first-lactation milk yield may be considered together with longevity and other functional traits in future breeding programs for Mugalzhar horses; however, the results should be interpreted in light of the observational design of the present study.