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Relevance. Herd horse breeding is the most ancient way of reproduction and maintenance of horses. The regularities of the growth and development of young animals largely depend on the genotype of the producers. Adai horses are bred in a herd way. Their well-being largely depends on natural and climatic conditions — the state of the weather, grass stand. The breeding zones of the Adai horse are the desert and semi-desert of the western region of Kazakhstan, characterized by a sharply continental climate.Methods. Experimental work was carried out at Taushyk LLP, Tupkaragan district, Mangistau region. The object of the study is pure-bred Kazakh horses of the Mangistau population and Adai offspring. According to scientific experience, two groups of 12 stallions were formed. Feeding qualities were assessed by the increase in live weight in young animals in the period from 24 to 30 months of age. Meat productivity was studied according to the methodology of the All-Russian Research Institute of Horse Breeding, in accordance with the technological instructions adopted in the meat industry.Results. It was found that the greatest increase in live weight in foals of Kazakh horses of the Adai offspring is observed from 3 days of age to 1 month and amounted to 42.9 kg with an average daily gain of 1530 g. For six months the increase in live weight was 84.1 kg, and average daily gain — 460 g. From 6 to 12 months of age the average daily gain in foals decreases to 126.9 g, due to the independent wintering of foals. From 18 to 24 months the minimum increase in live weight was recorded — 24.6 kg. From 24 to 30 months of age the average daily gains slightly increase — to 310 g. It has been established that the coefficient of increase in live weight in Kazakh horses in the conditions of the Mangyshlak Peninsula from birth to 24 months of age is 5.28–5.30, from 24 months. up to 30 months age — 0.51–0.52, from birth to 30 months of age — 8.54—8.56. It was found that the stallions of the Mangystau population exceeded their peers of the Adai offspring in terms of pre-slaughter live weight by 3.8 kg. In terms of slaughter yield stallions of the Adai offspring were inferior to their peers of the Mangistau population by 0.4%. The highest fat content in the meat of both groups is observed in the off-grade cut (kazy + sting) — from 16.0% to 16.4%. Comparatively little fat was contained in grade II meat — from 3.8% to 4.3% and grade III — from 2.3% to 2.7%.

Approximately 250 feral horses [Equus ferus caballus (Linnaeus, 1758)] living on Karadag Mountain near Karaman City were caught by Kazakh horse herdsmen with permission of the Turkish Ministry of Agriculture and Forestry and brought to a farm in Karkin village in Konya Province, 70 km from Karadag, in November, 2017. This study was carried out to determine the presence of ectoparasites infesting a subsample of 36 feral horses. The horses were visually inspected, and then their bodies were checked by hand for ectoparasites. Thirty-five (97.2%) were infested with at least one of five species of ectoparasites: Bovicola equi (Linnaeus, 1758), Hippobosca equina (Linnaeus, 1758), Haemaphysalis parva (Neuman, 1897), Hyalomma excavatum (Koch, 18449), Dermacentor marginatus (Sulzer, 1776). Most of the horses were coinfested with two ectoparasite species. Prevalence of infestation with H. equina was 80.6% and with B. equi 72.2%. In addition, prevalence of Ha. parva was 25.0%, Hy. excavatum 13.9%, and D. marginatus was 5.6%. This is the first systematic examination for external parasites of feral horses in Turkey. Further studies are needed to determine ectoparasites of greater numbers of feral horses in different localities.

There is an increasing demand for horse milk, but the current domestic performance of the horse milk has not yet conducted a systematic in-depth study. We carried out a pilot study on 13 single nucleotide polymorphisms (SNPs) located within five genes in Kazakh horse using Kompetitive Allele Specific PCR (KASPTM). An association study with average daily milk production of 60 Kazakh mares was performed for 6/13 polymorphic SNPs. The results showed that only two SNPs rs114262445 (NUMB), rs1136347938 (CA8) out of the 6 polymorphic markers were significantly associated with milk production in Kazakh horses. These results indicate the potential of using SNPs for the NUMB and CA8 genes as candidate genes for selection and farm production outputs. This study is relevant for future horse genomic studies.

Background miRNA has an important role in cell differentiation, biological development, and physiology. Milk production is an important quantitative trait in livestock and miRNA plays a role in the amount of milk produced. Methods The role of regulatory miRNAs involved in equine milk production is not fully understood. We constructed two miRNA libraries for Kazakh horse milk production from higher-producing (H group) and lower-producing (L group) individuals, and used RNA-Seq technology to identify the differentially expressed miRNAs between the two milk phenotypes of Kazakh horses. Results A total of 341 known and 333 novel miRNAs were detected from the H and L groups, respectively. Eighty-three differentially expressed miRNAs were identified between the H and L group s, of which 32 were known miRNAs (27 were up-regulated, five were down-regulated) and 51 were novel miRNAs (nine were up-regulated, 42 were down-regulated). A total of 2,415 genes were identified. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses showed that these genes were annotated to mammary gland development, mammary gland morphogenesis, tissue development and PI3K-Akt signaling pathways, insulin signaling pathway and TGF-beta signaling pathway, among others. Five miRNAs (miR-199a-3p, miR143, miR145, miR221, miR486-5p) were identified as affecting horse milk production and these five miRNAs were validated using qRT-PCR. Conclusions We described a methodology for the transcriptome-wide profiling of miRNAs in milk, which may help the design of new intervention strategies to improve the milk yield of Kazakh horses.

The utility of high-density single nucleotide polymorphism (SNP) data help to accurately identify genomic regions that have undergone positive selection. In this study, the Affymetrix Equine 670 K high-density SNP array was used to genotype Kazakh and Yili horse population. After quality control, 370,227 autosomal SNPs were used to detect selection signatures by using global fixation index (FST) and cross-population extended haplotype homozygosity (XP-EHH). The database of Ensemble, Genecards, and NCBI were used to make gene annotation and functional analysis. The results showed that there were 134 candidate SNPs overlapped between FST and XP-EHH in Kazakh horse. We also discovered some potential selective sweep regions associated with milk trait, including NUMB, LGALS2, ADCY8, SLC25A30, and CA8 genes. New findings from this research have potential value for milk traits selecting in horse.

This article examines interactions between Slavic peasant migrants and mobile pastoralist Kazakhs within the setting of the Kazakh Steppe during the period of heaviest resettlement to the region beginning in the late nineteenth century and continuing into the early twentieth century. It considers how the importance of horses to both settlers and Kazakhs alike dictated these interactions and how the sedentary world of the settlers disrupted the seasonal migration routes of Kazakh horse herders. Particularly with concern to the greatly expanded horse market, issues regarding land use, and increased instances of horse theft throughout the region, the Russian state’s encroachment into the steppe forever altered the social and economic makeup of the region.

This study was designed to provide a basis for further understanding of the mechanism of lactation based on mRNA expression differences in milk fat between different milk yields in Kazakh horses. Total RNA was extracted from the milk fat during the peak of lactation period. A total of 310 differentially expressed genes (DEGs) were identified by comparative transcriptome analysis of the high-yield and low-yield group. These DEGs regulate lactation by participated in AMPK signaling pathway, FoxO signaling pathway, ErbB signaling pathway, VEGF signaling pathway. In addition, we performed quantitative PCR to validated 5 selected DEGs and the results were in agreement with RNA-seq analysis. A new profile has been established for revealing the mechanism of equid's mammalian lactation.

The Kazakh horse is an important old horse breed in Xinjiang. They have contributed greatly to the breeding and improvement of other local horse breeds, yet their genetic diversity and population structure are not well understood. In the present study, we evaluated the genetic diversity of Kazakh horses and their relationship with other horse breeds using the mtDNA D-loop region, Cyt b gene, and a DNA fragment (nps 7974-9963, containing COX3, tRNA-Gly, ND3, and tRNA-Arg). A total of 130 Kazakh horses from 8 populations in China and Kazakhstan were analyzed. A total of 88 haplotypes (haplotype diversity: 0.9895) were identified, in which 3 haplotypes were shared by groups in the two countries. In a median-joining network, 6 haplogroups were found, in which most haplogroups included haplotypes from different populations. Neighbor-joining analysis revealed similar results in that haplotypes in different populations were admixed in most of the 6 clusters. In conclusion, a high level of genetic diversity was found in the Kazakh horses. However, no clear correspondence between haplogroups and geographic origin and no significant differentiation between populations in the two countries were observed. This might have resulted from the frequent contact between the two countries through the Silk Road in the past, or due to long-term outcrossing and hybridization with the introduced horses.

Recent studies have found that copy number variations (CNVs) are widespread in human and animal genomes. CNVs are a significant source of genetic variation, and have been shown to be associated with phenotypic diversity. However, the effect of CNVs on genetic variation in horses is not well understood. In the present study, CNVs in 6 different breeds of mare horses, Mongolia horse, Abaga horse, Hequ horse and Kazakh horse (all plateau breeds) and Debao pony and Thoroughbred, were determined using aCGH. In total, seven hundred CNVs were identified ranging in size from 6.1 Kb to 0.57 Mb across all autosomes, with an average size of 43.08 Kb and a median size of 15.11 Kb. By merging overlapping CNVs, we found a total of three hundred and fifty-three CNV regions (CNVRs). The length of the CNVRs ranged from 6.1 Kb to 1.45 Mb with average and median sizes of 38.49 Kb and 13.1 Kb. Collectively, 13.59 Mb of copy number variation was identified among the horses investigated and accounted for approximately 0.61% of the horse genome sequence. Five hundred and eighteen annotated genes were affected by CNVs, which corresponded to about 2.26% of all horse genes. Through the gene ontology (GO), genetic pathway analysis and comparison of CNV genes among different breeds, we found evidence that CNVs involving 7 genes may be related to the adaptation to severe environment of these plateau horses. This study is the first report of copy number variations in Chinese horses, which indicates that CNVs are ubiquitous in the horse genome and influence many biological processes of the horse. These results will be helpful not only in mapping the horse whole-genome CNVs, but also to further research for the adaption to the high altitude severe environment for plateau horses.