Zootechnical characteristics of the emerging lines of stallions of the Yakut breed in the Oymyakonsky ulus of Yakutia

Purpose: zootechnical characteristics of the developing lines of Yakut breed stallions in the breeding farm "Agricultural production cooperative "Tonor" of the Oymyakon ulus of Yakutia. Materials and methods. The study of the exterior indicators of the stallions was carried out by taking body measurements according to the instructions of the All-Russian Research Institute of Horse Breeding. The use of genotypic assessment methods for animals along with classical zootechnical assessment methods for pedigree, productive traits (live weight and meat productivity of offspring, milk production, fertility of daughters) was supplemented by the use of the method of selecting offspring based on their adaptability to herd conditions. Results. Long-term selection work in the breeding farm of the Oymyakon ulus is completed by the formation of six lines of outstanding Yakut breed stallions. In terms of live weight, both stallions and mares of the Oymyakon horse surpass stallions and mares of the Yana, Kolyma and indigenous types. Oymyakon stallions (n=20) weighed on average 483,7±3,55 kg, while stallions of the indigenous types weighed 446,3±4,75 kg (n=34), Kolyma types 449,1±3,42 kg (n=87) and Yana types 469,4±3,27 kg (n=128). Oymyakon horse mares (n=165) also surpassed mares of the indigenous type (401,6±2,00 kg (n=341)), Kolyma type (432,2±1,13 kg (n=1063) and Yang type (431,0±1,16 kg (n=881)) in average live weight of 453,8±2,19 kg. According to measurements of head, neck, chest, croup, occiput and withers, chest and croup width and their indices, Oymyakon horse stallions and mares are practically no different from indigenous type horses. The founder of the line with the most numerous followers is the outstanding stallion Kyurzhet, born in 1946. He came from local Yakut horses of the former Bolshevik collective farm. His line continues on the Tonor farm through his two descendants: his grandson Chalay, born in 1981, live weight 515 kg, and his great-grandson Tenkelekh, born in 1992, live weight 490 kg. The farm produced Kyurzhet's great-great-great-grandson Chalay and 6 great-great-great-great-grandchildren, and now produces 11 continuers of the line (3 great-great-great-great-grandchildren and 8 great-great-great-great-great-grandchildren), a total of 18 continuers of his line have been and are being produced.