In our study, we estimated the frequency of haplotype for cholesterol deficiency (HCD) carriers in the Russian Holstein cattle population. We studied 1817 random samples of cows born in 2010-2017 from ten herds and 331 cows and heifers from the other three herds born in 2016-2019, fathers or fathers of mothers of which were HCD carriers. The method of AS-PCR was used for animals genotyping. In the first group of animals, the incidence of HCD carriers was 8.09%, and in the second one - 23.26%. Our results demonstrated the necessity to test cows for the carriage of the HCD genetic defect in the Russian population of Holstein cattle.

Conservation of genetic resources by semen cryopreservation is essential for biodiversity conservation and storage of rare poultry breeds. Despite the widespread use of this method not all individuals presentia similar capacity for semen to be used after defrosting. The aim of the current study was to identify SNP markers and linked candidate genes potentially associated with rooster (Gallus gallus) sperm motility after cryopreservation. Genome-wide association studies were performed using 33 roosters from four breeds genotyped using Illumina Chicken 60K SNP BeadChip Calculations were performed using PLINK and EMMAX software. Significant SNP associations rs15557972 (p<1.36E-07) on chromosome 10 in the LOXL1 gene and rs15751385 (p<6.10E-06) on chromosome 6 in the intron of the ENSGALG00000052127 gene were identified. These findings associated with sperm motility SNPs will help to develop strategies for the selection of valuable individuals and the efficient conservation of the gene pool.