Domestic Breeds Research Articles

Formation of national varietal resources: status and prospects

Purpose. To study the current state and structure of national plant variety resources, analyse the dynamics of their formation, identify new challenges and threats to national interests and food security of the state. Methods. The research used general scientific methods including hypothesis, observation, search with elements of extrapolation from the source database, analysis, comparative evaluation and synthesis to draw conclusions. Results. The physical and geographical location of Ukraine in the centre of Europe determines the export­import segment of resources of varieties and hybrids, which depends on international trends and trends in the food market. In recent years, our country has lost its leading position in the market of varietal plant resources. At the beginning of the third quarter of 2024, the share of varieties of Ukrainian applicants in the State Re­gister of Plant Varieties Suitable for Distribution in Ukraine was lower than that of foreign varieties, slightly exceeding 44% (corn – 45.3%, sunflower – 32.9%, vegetables – 23.3%, rapeseed – 19.1%, beetroot – 19.2%). Currently, the priority of domestic breeding is maintained for the following groups: cereals – 52.3%, fodder – 64.2%, medicinal – 88.7%. According to experts, in the coming years three quarters of the varieties of plants grown in our country will be of foreign origin. This situation is of great concern not only because of the increased dependence on imports, but also because of the real prospect of the decline of domestic breeding and the emergence of risks in the field of plant variety rights protection. The reasons for this state of national varietal resources and trends in the development of the seed industry of the main strategic varieties were analysed, taking into account the production of seeds of both foreign and domestic breeding, the market share of which was determined during the research. The volumes and the main producers of conditioned seeds in Ukraine were determined. Conclusions. The state of plant variety resources was analysed, trends and main problems arising in the process of their formation were identified. The main directions of development and implementation of the norms of the European national legislation in the field of protection of rights to plant varieties and seed production were determined.

Yield, grain quality and morphological characteristics of new early maturing varieties of soybean [Glycine max (L.) Merrill] from domestic breeding

Purpose. To carry out a comprehensive study and evaluation of new varieties of soybean [Glycine max (L.) Merrill] of the early maturity group (vegetation period – 91–110 days) by morphological characteristics and the main economic indicators: yield, oil and protein content. Methods. Field stu­dies on the qualification examination of soybean varieties were carried out during 2022–2023 in ten branches of the Ukrainian Institute for Plant Variety Examination (UIPVE) within the soil and climatic zones of the Steppe, Forest­Steppe and Polissia. The process was based on the existing methods of qualification examination of plant varieties for their suitability for distribution in Ukraine (VCU), determination of quality indicators of crop production and compliance of varieties with the criteria of distinctness, uniformity and stability (DUS). Results. The morphological characteristics, yield and grain quality of new early maturing varieties of Ukrainian breeding, included in the State Register of Plant Varieties Suitable for Distribution in Ukraine, were evalua­ted. Namely: ‘Zlatopilska’, ‘Kobuko’, ‘AFC Tempo’, ‘AFC Fest’, ‘Hospodynia’ and ‘Sunrise’. The most productive varieties in all soil and climate zones were ‘AFC Tempo’ (Steppe – 3.25 t/ha, Forest­Steppe – 3.64, Polissia – 3.63 t/ha) and ‘Kobuko’ (Steppe – 3.03 t/ha, Forest­Steppe – 3.68, Polissia – 3.42 t/ha). At the same time, ‘Zlatopilska’, ‘Kobuko’, ‘AFC Tempo’, ‘AFC Fest’ and ‘Sunrise’ produced the highest yields in Forest­Steppe [from 2.89 t/ha (‘Zlatopilska’) to 3.68 t/ha (‘Kobuko’)] and ‘Hospodynia’ – in Polissia (2.83 t/ha). ‘Zlatopilska’ (38.4–40.3%) and ‘Sunrise’ (37.9–40.6%) had the highest protein content in the grain and ‘AFC Fest’ (23.3–24.3%) the highest oil content. Conclusions. According to the results of the qualification examination, varieties of soybean ‘Zlatopilska’, ‘Kobuko’ and ‘AFC Tempo’ are recommended for cultivation in all soil and climatic zones; ‘Sunrise’ – in the Steppe and Forest­Steppe; ‘Hospodynia’ – in the Steppe and Polissia; ‘AFC Fest’ – only in the Steppe. Seeds produced in the Forest­Steppe zone have the best quality indicators in terms of protein content, and in terms of oil content – in the Steppe zone. The studied varieties of soybeans meet the criteria of distinctness, uniformity and stability, as well as the requirements for suitability for distribution in Ukraine.

The history of the breeding of Clematis (Clematis L.) in the M. M. Gryshko National Botanical Garden, NAS of Ukraine

Purpose. Investigate the history of Clematis breeding in the M. M. Gryshko National Botanical Garden (NBG), NAS of Ukraine, determine the main directions of hybrid Clematis breeding work. Results. It was established that the result of more than 16 years of breeding Clematis in the NBG was the selection of the 61 perspective hybrid, 42 of which, the most perspective, were assigned names. Of these, large­flowered varieties are the most numerous according to the distribution of variety groups in the current Royal Horticultural Society of Great Britain classification. In particular, Late Large­flowered account for about 40% of the total and Early Large­flowered for about 29%. Small­flowered hybrids make up the smaller part, of which about 26% belong to the Viticella group and one hybrid (‘Sputnik’) to the Integrifolia. The known directions of distribution of hybrid Сlematis of the NBG breeding indicate the possibility of their successful cultivation both in continental and maritime areas with a high level of humidity in the temperate zone and in the dry Mediterranean climate of the subtropical climate zone, which reveals their significant adaptive potential. Conclusions. Obtaining varieties of hybrid Clematis of domestic breeding is important for the implementation of sustainable horticulture practices on the territory of Ukraine, since a significant part of the modern introduced assortment of Clematis raises doubts about their adaptability to the local climate, and requires additional research into their adaptive potential. A successful combination in vertical landscaping of NBG­bred Clematis belonging to different varietal groups can ensure continuous flowering from May to the end of the season. These unique characteristics of Clematis ensure the creation of not only environmentally sustainable, but also visually appealing spaces that will contribute to the overall health and beauty of the urban environment.

Germplasm Resources Evaluation of Cultured Largemouth Bass (Micropterus salmoides) in China Based on Whole Genome Resequencing.

Background: Largemouth bass (Micropterus salmoides), a valuable freshwater fish species, has experienced significant genetic decline in China due to prolonged domestic breeding and limited introduction of new genetic material. It is necessary to have a comprehensive understanding of the genetic status of largemouth bass populations in China. Method: In this study, we conducted population genetic analyses on nine cultured largemouth bass populations using whole genome resequencing. Results: A total of 3.23 Tb of clean bases were generated, with average Q20 and Q30 values of 98.17% and 94.25%, respectively, and 2,140,534 high-quality SNPs were obtained. Relatively high genetic diversity was observed across all populations. Combined with linkage disequilibrium (LD) patterns, the Wanlu (WL) population possessed the highest genetic diversity, and the Longyou (LY) population possessed the lowest genetic diversity. Additionally, population structure analyses, including pairwise F-statistics, phylogenetic trees, PCA, and admixture analysis, revealed significant genetic differentiation, particularly between the WL, LY, and other 7 populations, while also indicating the occurrence of a common admixture event. Finally, TreeMix inferred migration events from the WL to the Chuanlu (CL) population and from the Taiwan breeding population (TWL) to the Guanglu (GL) population. Conclusions: These findings provide a critical foundation for developing conservation and breeding strategies for largemouth bass in China.

Analysis of genetic evolutionary differences among four Tibetan pig populations in China

Tibetan pigs are a locally bred domestic pig breed originating from the Tibetan Plateau in China. They can be categorized into four distinct groups based on their geographical locations: Sichuan Tibetan pigs, Tibetan pigs from Tibet, Yunnan Tibetan pigs, and Gansu Tibetan pigs. This study aimed to explore population diversity, genetic structure and selection signals among Tibetan pigs in four Chinese national nature reserves. The results show that there is different observed heterozygosity among Tibetan pig populations (0.1957–0.1978). Ratio of runs of homozygosity (Froh) calculation of four Tibetan pig populations by runs of homozygosity (ROH) revealed the presence of inbreeding within the population (0.0336–0.0378). Analysis of the genetic structure demonstrated distinct population stratification among the four Tibetan pig populations, with each showing relatively independent evolutionary directions. Furthermore, Five methods (FST, Piratio, ROD, Tajima's D, XP-CLR) were used to artificially select evolutionary trajectories. The results mainly involved processes such as DNA repair, immune regulation, muscle fat deposition and adaptation to hypoxia. In conclusion, this study enhances our understanding of the genetic characteristics of Tibetan pig populations and provides a theoretical reference for the conservation of resources across different populations of Tibetan pigs.

Comparative analysis of meat quality of Laiwu black, Minxinan black and Hyla rabbits

Abstract. The meat rabbit industry in China relies on foreign breeds and synthetic lines; the development of superior domestic breeds has not yet been fully realised. We compared the meat quality of two Chinese local breeds of black rabbits (Laiwu black and Minxinan black) and Hyla commercial rabbits, to provide a reference for the utilisation of meat rabbit breeds. In the present study, 35 d old Laiwu black rabbits, Minxinan black rabbits, and Hyla rabbits (20 rabbits each) were selected and reared under identical feeding and management conditions for 7 weeks, after which 10 randomly selected rabbits from each group were slaughtered for the analysis of meat quality. The a∗ (redness) value of the two local breeds was significantly higher than that of Hyla rabbits (p<0.01). The shearing force and drip loss of Laiwu black rabbits were significantly lower than those of the other groups (p<0.05). The two local breeds exhibited significantly higher myoglobin levels than Hyla rabbits (p<0.01), while melanin was highest in the meat of Minxinan black rabbits. The essential amino acids (valine, isoleucine, leucine and lysine) were significantly lower in Minxinan black rabbits than in the other groups (p<0.05). Aldehyde (heptanal, octanal) contents in Minxinan black meat were significantly higher than those of the other groups (p<0.01); however, nucleotide (guanine, adenine) contents were significantly lower (p<0.01). Unsaturated fatty acids (oleic, linoleic, α-linolenic) were significantly higher in the meat of Laiwu black rabbits than in those of the other groups (p<0.05). Both Laiwu black and Minxinan black rabbits have certain advantages in terms of nutritional indicators while also having good meat colour and flavour. The results of this study provide a theoretical reference for the research and development of meat rabbit breeds.

Accelerated reproduction of the parental lines of white cabbage using rosette plants (steckling) and artificial climate chambers

Relevance. The technology of producing cabbage seeds with the traditional method takes almost 2 years. Its high labor intensity caused the need to search for cheaper methods of selection and seed production. One of the ways to speed up the stages of the selection process is the use of artificial climate chambers. The aim of research is to obtain seeds of promising inbred lines of late maturing white cabbage and hybrid combinations with their participation using rosette plants (steckling) in artificial climate chambers. Materials and Methods. The material was inbred pure lines of 5-6 generations of inbreeding, obtained from promising hybrid combinations of domestic and foreign breeding. The research was conducted in 2023-2024. Sowing in Plantek 64 cassettes was carried out on July 10, then the seedlings were transplanted into vegetative vessels with an optimal volume of 5-6 liters and installed in the open ground for the growth of a leaf outlet. In the phase 10-13 of real leaves, the plugs were placed in an artificial climate chamber. During the growth and development period, biometric and phenological observations were carried out, and an analysis of seed setting was carried out during the hybridization of inbred lines.Results. As a result of research in the study of hybrid seed production under artificial climate chamber conditions, high rates of seed setting in buds under cross-pollination of rosette plants of white cabbage were revealed. Genotypes with high seed set rate under geitenogamous bud pollination were also identified. The weight of 1000 seeds of the studied plants was within the range of 2.5-5.14 g. Genotypes 383-3, 384-2 and 384-7 were selected, which had the highest percentage of seeds in the fractional composition with size more than 2 mm 80.3%, 43.5% and 59.4%, respectively. When genotypes 384-2 and 384-7 were used in hybrid combinations as a maternal component, high quality indicators of the obtained seeds were revealed.Conclusion. For the studied genotypes of white cabbage, when grown in an artificial climate chamber, no significant effect on seed quality was found; the genotype had a greater effect on seed quality indicators.

The Population History of Domestic Sheep Revealed by Paleogenomes.

Sheep was one of the first domesticated animals in Neolithic West Eurasia. The zooarchaeological record suggests that domestication first took place in Southwest Asia, although much remains unresolved about the precise location(s) and timing(s) of earliest domestication, or the post-domestication history of sheep. Here, we present 24 new partial sheep paleogenomes, including a 13,000-year-old Epipaleolithic Central Anatolian wild sheep, as well as 14 domestic sheep from Neolithic Anatolia, two from Neolithic Iran, two from Neolithic Iberia, three from Neolithic France, and one each from Late Neolithic/Bronze Age Baltic and South Russia, in addition to five present-day Central Anatolian Mouflons and two present-day Cyprian Mouflons. We find that Neolithic European, as well as domestic sheep breeds, are genetically closer to the Anatolian Epipaleolithic sheep and the present-day Anatolian and Cyprian Mouflon than to the Iranian Mouflon. This supports a Central Anatolian source for domestication, presenting strong evidence for a domestication event in SW Asia outside the Fertile Crescent, although we cannot rule out multiple domestication events also within the Neolithic Fertile Crescent. We further find evidence for multiple admixture and replacement events, including one that parallels the Pontic Steppe-related ancestry expansion in Europe, as well as a post-Bronze Age event that appears to have further spread Asia-related alleles across global sheep breeds. Our findings mark the dynamism of past domestic sheep populations in their potential for dispersal and admixture, sometimes being paralleled by their shepherds and in other cases not.

Chromosome-level genome assembly of Huai pig (Sus scrofa)

Although advances in long-read sequencing technology and genome assembly techniques have facilitated the study of genomes, little is known about the genomes of unique Chinese indigenous breeds, including the Huai pig. Huai pig is an ancient domestic pig breed and is well-documented for its redder meat color and high forage tolerance compared to European domestic pigs. In the present study, we sequenced and assembled the Huai pig genome using PacBio, Hi-C, and Illumina sequencing technologies. The final highly contiguous chromosome-level Huai pig genome spans 2.53 Gb with a scaffold N50 of 138.92 Mb. The Benchmarking Universal Single-Copy Orthologs (BUSCO) completeness score for the assembled genome was 95.33%. Remarkably, 23,389 protein-coding genes were annotated in the Huai-pig genome, along with 45.87% repetitive sequences. Overall, this study provided new foundational resources for future genetic research on Chinese domestic pigs.

The Integration of Veterinary Medicine and Behavioral Management in the Care of Captive Pigtail Macaques (Macaca nemestrina)

The Washington National Primate Research Center (WaNPRC) maintains the largest domestic breeding colony of pigtail macaques (Macaca nemestrina) in the United States, with animals housed in small to medium-sized social groups. As part of the animal care plan, a programmatic framework is utilized, which integrates clinical care with socialization considerations for nonhuman primates (NHPs). This framework encompasses the following areas: (1) socialization in the clinical setting; (2) positive reinforcement training (PRT); (3) measures to ensure proper identification and medication distribution; and (4) in-group treatments. The success of this framework is demonstrated by the high socialization rate for hospitalized animals (99.5% social pairing success), with the majority of clinical cases (95%) being treated in social groups. Ultimately, this framework seeks to buffer stressors when animals require clinical care or husbandry manipulations. Taken together, the above components foster an environment that provides a comprehensive approach to NHP medical and behavioral management.

Influence of weather conditions on the duration of the growing season and economically valuable traits and properties of soybean varieties of domestic and foreign selection

The influence of meteorological conditions of the region on the duration of the vegetation period and production process of domestic and foreign soybean breeding was determined. The research was conducted in the period 2021–2023 in the Bryansk region. 18 soybean varieties included in the Register of breeding achievements admitted to use were taken as an object of research. According to the duration of the vegetation period varieties are divided into three groups of ripeness: fast-ripening – Vita, Lira, Leader 10, Amadea, Lisbon, Vera, early-maturing – Protina, Volma, Kora, Zusha, Mezenka, Osmon, Sultana, medium-maturing – Sculptor, Pripyat, Puma, Sirelia, Ros. It was revealed that, on average, plant height increased with the increasing vegetation period: fast-ripening – 75.8 cm, early-maturing – 77.3, medium-maturing – 83.0 cm. It was revealed that, on average, with an increase in the growing season, the height of plants increased: precocious – 75.8 cm, early-maturing – 77.3 cm, middle-maturing – 83.0 cm. 4 genotypes (22 %) with low attachment of the lower beans were identified: Vera, Kora, Pripyat, Sirelia, 11 varieties (61 %) with medium attachment of the lower beans: Vita, Lira, Leader 10, Amadea, Lisbon, Volma, Zusha, Osmon, Sultana, Sculptor, Puma, 3 varieties (17 %) with a high attachment: Protina, Mezenka, Ros. The weight of 1000 seeds was calculated – varieties with larger filled seeds: Sultana (176), Ros (177), Lisbon (162), Vita (158), Vera (158), Sirelia (158). Varieties with the highest seed yield were identified: Ros (25.3 c/ha), Zusha (22.8), Sculptor (22.2), Pripyat (22.2), Lisbon (22.1 c/ha). Crude protein was determined by the Kjeldahl method, crude fat by the Soxhlet. The high content of crude protein was formed by the varieties of domestic breeding: Puma (36.66%), Mezenka (35.95%), Osmon (35.75%), Vera (35.34%); foreign varieties: Sirelia (39.05%), Sultana (38.27%), Pripyat (36.17%). The crude fat content in the seeds varied both by year and by variety. The maximum fat value was noted in the genotypes: Ros (23.78%), Mezenka (23.72%), Sculptor (23.18%), Zusha (22.45 %), Sultana (22.36%).

A New Perspective on Türkiye's Sheep Population: Classification with Decision Trees

Decision trees are data mining algorithms that make interpreting the cause-effect relationship or classification between features with visual diagrams easy and do not require parametric assumptions. The aim of this study is to classify different sheep breeds raised in Turkey according to their origin and tail structure characteristics using a decision tree algorithm. It has been seen that the CART (Classification and Regression Trees) algorithm is sufficient for the classification of sheep breeds by obtaining low-risk values. According to the results of the study, it is seen that domestic sheep breeds are distributed to Eastern Anatolia, Mediterranean, Black Sea, and Central Anatolia Regions and imported breeds are distributed to all regions of Türkiye. The total population of these breeds was determined as 43.889.918 heads. As it can be understood, the Akkaraman breed ranks first with a rate of 40.88% of the total sheep stock. Next comes the Morkaraman breed with a rate of 11.68%. Thirdly, the most cultivated breed is Kıvırcık, whose rate is 8.82%. Merino sheep comes in fourth place with 8.43%. Awassi sheep are among the most common breeds in the fifth place. Hereby the distribution of sheep breeds in Türkiye has also been revealed and the distribution of breeds according to environmental conditions has been determined. The decision tree model generated using the CART algorithm for the distribution of sheep breeds in Turkey based on tail structures has been found to have a value (0.47). The proportion of sheep with a thin tail structure is 52.2%, while those with a semi-fatty tail structure are 17.5%, and those with a fatty tail structure are 30.2%. It has been determined that sheep breeds with thin tails are more commonly raised in Turkey. In the study, a decision tree model was also created using the CART algorithm to analyze the distribution of sheep populations in regions based on their origin, and it was found to have a value (0.26) with an accuracy rate of 74%. According to the research, 73.9% of sheep are domestic, while 26.1% are imported. When examining the distribution of origin by region, the region with the least number of imported sheep is Eastern Anatolia, while the highest proportions are found in the Mediterranean and Black Sea regions. The region with the lowest proportion of domestic sheep is the Mediterranean and Black Sea (70.4%), whereas the highest proportion is in the Eastern Anatolia region (82.6%).

Invasive wild boar affected feral hog skull evolution over 25 years in Brazilian Pantanal wetland

Abstract The morphological plasticity of the Sus scrofa wild–domestic species complex is evident in both free-ranging morphotypes and domestic breeds. The Brazilian Pantanal feral hog (“porco-monteiro”) evolved after a long-term feralization process and represents a significant proportion of the mammalian biomass in the region. Its coexistence with native fauna brings several ecological impacts, which are mitigated by the Brazilian Pantanal wetland vastness and resource availability. They are a local subsistence game resource but also impact crops and pastures. Around the 2000s to mid-2010s, numerous European wild boar were introduced in Brazil to fulfill a demand for gourmet meat. Wild boar was also introduced to the Brazilian Pantanal as a game species and to breed with porco-monteiro feral hogs in a commercial venture to produce an even more exotic meat. The craze for wild boar meat has since dwindled, but their populations remain widespread and uncontrolled. Moreover, the full impact of the wild boar introduction on feral hog populations is still unknown. This study analyzes the skulls of porco-monteiro feral hogs from the 1990s, 2000s, and 2010s to assess possible morphological and functional variations along with skulls of wild boar and hybrids from Argentina, Uruguay, and Southern Brazil. The results indicate a trend of broadening of feral hog skulls at the coronal plane and a progressive reduction of the semispinalis capitis muscle scars over the decades. Biomechanical analysis denoted a decrease in head-elevation force that could affect the rooting performance of the latest feral hog morphotypes. Taken together, results show that wild boars likely influenced the evolution of the Pantanal feral hog skull. The magnitude of ecomorphological implications of these morphofunctional changes is unknown, as well as its effects in the Brazilian Pantanal wetland ecology.

Caprine and Ovine Genomic Selection-Progress and Application.

The advancement of sequencing technology and molecular breeding methods has provided technical support and assurance for accurate breeding. Genomic Selection (GS) utilizes genomic information to improve livestock breeding, and it is more accurate and more efficient than traditional selection methods. GS has been widely applied in domestic animal breeding, especially in cattle. However, there are still limited studies on the application and research of GS in sheep and goats. This paper outlines the principles, analysis methods, and influential factors of GS and elaborates on the research progress, challenges, and prospects of applying GS in sheep and goat breeding. Through the review of these aspects, this paper is expected to provide valuable references for the implementation of GS in the field of sheep and goat breeding.

Genome resequencing reveals genetic status of Macrobrachium rosenbergii populations in China

The giant freshwater prawn (Macrobrachium rosenbergii) has been widely cultured in China since 1990s. In this study, 189 individuals were sampled from 10 distinct populations, including original populations introduced from abroad and domesticated strains in China, namely Florida (FD), "Nantaihu No.2" (NT), Vietnam (YN), Sri Lanka (SK), Bangladesh (ML), Thailand (TG), Taiwan (TW), "Shufeng No.1" (SF), Zhengda (ZD) and New Myanmar (NMD). The genetic diversity and population structure of these populations were analyzed based on a dataset of 300,828 genome-wide SNP loci. The population structure analysis showed that the 10 populations shared 4 ancestors, and the domestic populations (i.e., SF, ZD, TW and NT) shared a common ancestor. The phylogenetic analysis showed that the 10 populations were grouped into 4 branches, with all the domestic populations clustering together. Estimation of fixation index (Fst) values revealed relatively lower Fst values among the domestic populations, in contrast to the more significant differences observed between domestic and foreign-origin populations. Gene flow analysis revealed three significant events of genetic exchange among the 10 populations: (1) from YN to the common ancestor of FD, TG and the domestic populations, (2) from NMD to the common ancestor of TG and FD, and (3) from the common ancestor of NMD, YN, ML and SK to ZD population. In addition, selective sweep analysis, utilizing Fst and nucleotide diversity (Pi) estimations, was conducted on representative populations (i.e., ML and SF), and 7 positively selected genes were identified, including Prospero Homeobox 1 (Prox1), Forkhead Box L1 (Foxl1), Tousled Like Kinase 2 (TLK2), G Protein Subunit Alpha 14 (Gna14), Uronyl 2-sulfotransferase (Ust), MAX Network Transcriptional Repressor (Mnt) and Importin-9 (Ipo9). These findings contribute to elucidating the breeding potential of the introduced populations and provide insights into the genetic status of the domestic breeding strains of M. rosenbergii in China.

Purposive breeding strategies drive genetic differentiation in Thai fighting cock breeds.

Fighting cock breeds have considerable historical and cultural place in Thailand. Breeds such as Lueng Hang Khao (LHK) and Pradu Hang Dam (PDH) are known for their impressive plumage and unique meat quality, suggesting selection for fighting and other purposes. However, information regarding the genetic diversity and clustering in indigenous and local Thai chickens used for cockfighting is unclear. To investigates the genetic diversity and differentiation in Thai fighting cock breeds, including populations for cockfighting, ornamental aspects, and consumption. Thai fighting cook breeds, including LHK and PDH chickens were analyzed using genotyping with 28 microsatellite loci. Data were compared to a gene pool library from "The Siam Chicken Bioresource Project" to understand the impact of human selection on genetic differentiation. Fighting cock strains from different breeds may cluster owing to shared breeding goals. The analysis of several chicken breeds showed subpopulation differentiation driven by artificial selection and genetic drift, affecting the genetic landscape and causing genetic hitchhiking. Eleven of 28 microsatellite loci showed hitchhiking selection, indicating directional selection in fighting cocks. Additionally, analyses revealed admixture with domestic chicken breeds and minimal influence of red junglefowl in the gene pool of Thai fighting chickens. These findings inform breed improvement, selection strategies, genetic resource management, and maintaining genetic diversity in fighting cocks. Analysis of Thai Fighting chicken breeds revealed a correlation between utilization and subpopulation differentiation. Specifically, selection for cockfighting and ornamental traits appears to explain the observed genetic structure within these breeds.

GENETIC DIVERSITY OF AWASSI SHEEP REARED IN FERTILE CRESCENT BASED ON MICROSATELLITES: A REVIEW

In general, many domestic breeds of livestock evolved to different geographical regions, Awassi sheep in particular, adapted to Fertile Crescent region where cradle of domestication took place. Awassi sheep has tremendous genetic diversity compared to other domestic sheep breeds of the world. Nowadays, Awassi sheep is in danger of losing their unique and ancient genetic diversity as a result mainly of unwarranted crossing with high-yielding exotic breeds. Another reason for losing diversity is reduction in the population size of Awassi sheep in their origin region of the Fertile Crescent. Unveiling genetic diversity marks the inaugural phase in the execution of breeding and conservation initiatives. Previous literature revealed that microsatellite markers were widely used and accepted until nowadays as useful molecular markers for evaluating genetic diversity of sheep populations along with other markers such as Single Nucleotide Polymorphisms (SNP). Most studies based on microsatellite markers provided information on genetic diversity parameters (e.g. observed and expected heterozygosity, PIC, alleles number, inbreeding coefficient, effective population size, genetic distances values and cluster analyses) within and among Awassi populations. These markers enabled phylogenetic relationships among populations by tree building approach based on genetic distance values. On the other hand, crossbreeding practices are thought to contribute to the genetic erosion of the original Awassi sheep breed, while a reduction in population size is anticipated to have adverse effects on genetic diversity. In this work, we reviewed the microsatellite-based studies which have been published for detecting genetic diversity of Awassi sheep breed in various countries of Fertile Crescent. Key words: Genetic diversity, Awassi Sheep, Fertile Crescent, Genetic Markers.

Developmental variations of the reproductive organs of ganders from different goose breeds and the underlying mechanisms

A deep understanding of the dynamics and mechanisms of male reproductive tract development is necessary for adoption of either genetic techniques or environmental management practices for improving fertility and hatchability in poultry. However, compared with other poultry such as chickens and ducks, less is known about the age- and breed-related changes in the reproductive tract development of domestic goose ganders exhibiting relatively poor reproductive performance as well as the regulatory mechanisms. In the present study, by taking 2 Chinese domestic goose breeds (Sichuan White goose, SW and Gang goose, GE; Anser cygnoides) and one European goose breed (Landes goose, LD; Anser anser) as the experimental objects, we comprehensive analyzed the morphological, histological, and genome-wide transcriptomic variations in their testicular and external genital development during the period from hatching to sexual maturity. Results from histomorphological analysis demonstrated that the reproductive tract of all goose breeds developed in both age- and breed-dependent manners, and the left and right testis developed asymmetrically throughout posthatch development. The tenth week posthatch was a critical developmental stage for all goose ganders, because both the testicular and external genital histomorphological parameters significantly changed before and after this period. During the first 10 wk posthatch, the weight, organ index, or size of male reproductive organs developed more rapidly in SW than in LD, and so were the testicular parenchymal-to-interstitial ratio and the external genital lymphatic lumen diameter. However, the testicular seminiferous epithelium thickness, seminiferous tubule diameter, and Leydig cell number, as well as the external genital keratinized epithelium thickness were significantly higher in LD than in SW at 10 wk of age. Through comparative transcriptomics analysis and RT-qPCR validation, several pathways related to germ and somatic cell function, organ remodeling, and energy metabolism were thought to be responsible for the developmental variations in the early testicular development between Chinese and European domestic ganders, where 10 hub genes involved in the cell cycle, RNA polymerase II-dependent transcription, and mitotic cell division pathways might play essential roles. These data shed new light on the interbreed differences in the male goose reproductive tract development and the molecular mechanisms regulating male goose testicular functions and fertility.

BREEDING ACHIEVEMENTS OF UKRAINE (PAST, PRESENT): BREEDS, TYPES AND LINES OF AGRICULTURAL ANIMALS

The purpose of the study was to establish chronologically breeding achievements in livestock breeding of Ukraine with the help of the relevant Register. To analyze the dynamics of the number of breeding animals, the State Register of Breeding Subjects in Livestock Breeding for the period 2002 ... 2022 was used. The genealogical structure of the six studied breeds of dairy cattle includes 10 interbreed and 11 local types, 47 local and 38 genealogical lines and about 244 families. Beef cattle are represented by four approved breeds, 4 interbreed and 2 local types, 32 lines and 172 families. The pedigree pig breeding of Ukraine includes seven domestic breeds with three interbreed types, 11 local types, 95 lines and 159 families. In the fields of sheep breeding and horse breeding, five and two breeds were created, respectively, and their genealogical structure was formed from 11 interbreed types and 28 families in sheep breeding and 15 lineages and related groups and 25 families in horse breeding. One breed and two crosses (10 lines) of laying hens, one cross (two lines and eight microlines) of turkeys and four breed groups of ducks represent poultry breeding.

PIGS OF MEAT BREEDS IN UKRAINE AND THE NEED FOR THE REVIVAL OF PIG BREEDING

The article highlights the peculiarities of pork production in Ukraine, examines the productivity of domestic and foreign meat breeds of pigs in the dynamics of 2002–2022. It was found that the meat pork market in Ukraine developed intensively from 2002 to 2016, with a sharp reduction thereafter. The breeds of pigs in the meat direction of productivity include Durok, Landras, Pietrain, Poltavian Meat, Welsh, Ukrainian Meat and Red White-Beltid with some changes in the breed composition during 2002–2022. It was established that until 2005, the leaders in the meat pork production market were the Ukrainian and Poltavian Meat breeds, which were later supplanted by Landrace pigs. The population of the main sows of the investigated breeds was 7.8–9.3% of the total number of pigs, including 8.9% in 2022, which ensured the necessary reproduction of animals with some nuances regarding small populations. In 2022, the number of queens of the landrace breed will be 87.7–98.8% higher than the number of the rest of the studied breeds. Sows of meat breeds, which were bred in breeding farms during 2002–2022, are characterized by significant variability of multifertility, and the difference in the trait within one breed quite often exceeded the interbreed difference. The variability of the best indicators of the age of pigs reaching a live weight of 100 kg in the process of their cultivation in representatives of the Durok breed during the years 2002–2022 was 164–178 days, Landras 148–183 days, Pietrain 150–154 days, Poltavian Meat 179–198 days, Welsh 156–187 days, Ukrainian Meat 174–187 days and Red White-Beltid 181–207 days. The highest indicators of average daily gains were among pigs of the Durok breed, which varied between 658–810 g, Landras 612–860 g, Pietrain 520–890 g, Poltavian Meat 574–735 g, Welsh 344–628 g, Ukrainian butchers 435–768 g and Red White-Beltid 470–635 g. It has been proven that Durok pigs in the best breeding herds had lard thickness at the level of 13–16 mm, Landras 10–12 mm, Pietrain 7–9 mm, Poltavian Meat 21–23 mm, Welsh 12–16 mm, Ukrainian Meat 16–20 mm and Red White-Beltid 22–23 mm. On the example of the genealogical structure of pigs of the Landrace and Pietrain breeds, as well as the market for the sale of breeding offspring and semen, the conduct of purebred breeding in subjects of the breeding business in the pig industry of Ukraine is questioned. In order to revive Ukrainian pig farming and bring order to breeding pig breeding, it is recommended to take into account the requirements for the functioning of the pig breeding industry in the countries of the European Union.