Impact of Inbreeding on Dairy Cow Survival
Year: 2024
Type: conference-abstract
Abstract: The dairy industry strives for sustainable practices, focusing on dairy cow health and longevity. However, inbreeding poses a significant challenge to this as it affects various traits negatively. This study investigates how pedigree (FPED) and genomic (FROH) inbreeding impact the survival of dairy cows post-first calving. Cox proportional hazards regression analysis on 56,309 Danish Jersey (JER) and 103,716 Danish Holstein (HOL) cows was used to estimate Hazard Ratios (HR) on different covariates. In the analysis, time was the cow’s lifespan from first calving until culling or to the data extraction date (censored records). FPED or FROH were used as continuous covariates in the analysis. Additionally, the analysis was performed across different runs of homozygosity (ROH) length categories: 1-2 Mb, 2-3 Mb, 3-5 Mb, 5-10 Mb, 10-17 Mb, and >17 Mb. Results indicated that overall, JER cows exhibited a lower HR for culling compared to HOL cows. We observed HR increases of 1% per FPED and 2% per FROH. Statistically significant HR coefficient increases were seen within ROH length categories 2-3 Mb, 5-10 Mb, 10-17 Mb, and >17 Mb. The largest HR coefficient was in the 2-3 Mb ROH category, with a 4% increase per Froh unit and the highest HR for mean Froh was in the 5-10 Mb ROH category, at a mean HR of 4.3%. No significant differences in HR were found between breeds within different ROH categories. In conclusion, inbreeding slightly increased HR, and higher HR was seen for the longer ROHs, which indicates that recent inbreeding is more harmful to dairy cows.
Institutions: Aarhus University, Norwegian University of Life Sciences
Language: English
Subfield: Genetics
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W4412217995