119 Genetic Highlights for Reproduction and Health Traits in Russian Black-and-White and Holstein Animals Selected for Production of High-Quality Embryos
Authors: Sermyagin A. A. , Conte A. F. , Volkova V. V. , Romanenkova O. S. , Kharzhau A. A. , Reyer H. , Wimmers K. , Brem G. , Zinovieva N. A. 
Published: November 2018

The aim of genetic improvement in cattle breeding is to create animals, which are characterised by high economic efficiency while maintaining the high breeding values for health and reproduction traits. In Russia dairy cattle industry the integrated approaches based on application of genomic methods for cows’ fertility and health traits along with milk production are being developed. However, their efficiency depends largely on the ability for multiple replicating outstanding individuals by embryo transfer. Therefore, the target of our research was to develop a strategy for the integrated genetic improvements of fertility and udder health traits towards the production of embryos with high estimated breeding values (EBV). We analysed the culling factors of more than 23,400 Black-and-White and Holstein cows of the Moscow region cattle population. Using the genotyping procedure by Illumina Bovine SNP50 BeadChip (Illumina Inc., San Diego, CA, USA), the regional training group consisted of 401 proven bulls and 60 pre-selected cows was formed. After the quality check based on Plink 1.90, we selected 39,631 single nucleotide polymorphisms for the analysis. The GBLUP methodology was used to calculate genomic EBV (GEBV). The cows were additionally tested by PCR or PCR-RFLP (restricted fragment length polymorphism) for LoF mutations in the genes FANCI, APAF1, SMC2, GART, ITGB2, SLC35A3, and APOB, associated with fertility haplotypes HH0, HH1, HH34, HH4, HHB, HHC, and HCD, respectively. The evaluation of genetic variances and EBV for days open (DO), breeding per conception (BC), calving ease (CE), somatic cell score (SCS), milk yield (MY), fat yield (FY), and protein yield (PY) was carried out using the BLUPF90 family of programs. Cows’ culling rate for reproductive traits was 21% and for udder diseases was 8%. The genetic correlations, rg, between SCS and cows’ fertility traits were rg = 0.132 for BC, rg = 0.067 for DO, and rg = –0.056 for CE that can be used as an indicator for the monitoring reproductive disorders at the different stages of lactation. The frequencies of fertility haplotypes’ carriers among the potential donor dams were 6.6, 1.1, 8.8, 0.0, 1.1, 0.0, and 4.4% for HH0, HH1, HH3, HH4, HHB, HHC, and HCD, respectively. Based on EBV and carrier status for LoF mutations, we selected 46 dams and 28 sires to produce embryos with high GEBV for MY (+633, ..., +884 kg), FY (+26 kg), PY (+18 kg), and SCS (106 points) and higher as population average GEBV for fertility and udder health traits. Genome-wide association study analysis by the reliability of Bonferroni correction test (P < 1.2 × 10−6) showed the presence of quantitative trait loci on BTA1, BTA5, BTA9, BTA11, BTA12, BTA27, and BTX. Our results will be used to construct Russian fitness index for dairy cattle and for implementing embryo production technology into the Russian breeding system.
Research supported by the Russian Science Foundation within Project no. 15-16-00020.