Recent evidence has suggested that some of the decline in reproductive ability in dairy cattle has been caused by embryonic death. In the Dairy Cattle Reproduction Council’s June 2015 Newsletter, DCRC shares a research summary on inbreeding and embryonic losses. Researchers at the University of Wisconsin compared expected genomic inbreeding from sire — dam mating pairs to genomic inbreeding from live progeny in an attempt to determine how embryonic inbreeding may affect fertility.
They examined data for 11,484 Holstein cattle with 43,485 single nucleotide polymorphism (SNP) markers and pedigree information. Results of the analysis suggest increases in expected genomic inbreeding do not explain a large effect on embryo viability at average levels of expected inbreeding.
Overall, expected genomic inbreeding measures were calculated, but results did not suggest a large effect of expected inbreeding on embryo viability. So while it’s still important to avoid inbreeding as much as possible when making mating decisions, it doesn’t appear, that inbreeding is responsible for increased embryonic death.