Abstract #59
Section: Breeding and Genetics (orals)
Session: Breeding and Genetics I: Health and Fertility
Format: Oral
Day/Time: Monday 10:15 AM–10:30 AM
Location: Room 301 B
Session: Breeding and Genetics I: Health and Fertility
Format: Oral
Day/Time: Monday 10:15 AM–10:30 AM
Location: Room 301 B
# 59
Single-step genome-wide association study of digital dermatitis and sole ulcer in Holstein cattle.
Francesca Malchiodi*1, Luiz F. Brito1, Anne-Marie Christen2, Allison Fleming1, David F. Kelton3, Flavio S. Schenkel1, Filippo Miglior1,4, 1Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada, 2Valacta, Sainte-Anne-de-Bellevue, QC, Canada, 3Department of Population Medicine, OVC, University of Guelph, Guelph, ON, Canada, 4Canadian Dairy Network, Guelph, ON, Canada.
Key Words: digital dermatitis, sole ulcer, ssGWAS
Single-step genome-wide association study of digital dermatitis and sole ulcer in Holstein cattle.
Francesca Malchiodi*1, Luiz F. Brito1, Anne-Marie Christen2, Allison Fleming1, David F. Kelton3, Flavio S. Schenkel1, Filippo Miglior1,4, 1Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada, 2Valacta, Sainte-Anne-de-Bellevue, QC, Canada, 3Department of Population Medicine, OVC, University of Guelph, Guelph, ON, Canada, 4Canadian Dairy Network, Guelph, ON, Canada.
Digital dermatitis and sole ulcer represent the most prevalent lesions in Canada, with almost 20% and 8% of cows affected by these lesions, respectively. This study aimed to perform a genome-wide association study (GWAS) and functional analysis to uncover genomic regions associated with digital dermatitis and sole ulcer. Hoof lesions were recorded by 51 hoof trimmers during the routine trimming activity in 1,080 Canadian herds between 2009 and 2016. Hoof lesions were coded as binary traits (0; 1), where 1 was assigned to the presence of a lesion in any claw. The final data set contained 249,709 observations from 105,450 animals, while the pedigree file contained 351,215 animals. Of those animals, 20,188 were genotyped either with 50K SNP panel or a low-density panel and imputed to 50K. The model implemented in the weighted single-step GWAS included the fixed effects of herd-date of hoof trimming, hoof trimmer, parity at trimming, stage of lactation at trimming, and the random additive genetic animal and permanent environmental effects. Important genomic regions associated with digital dermatitis and sole ulcer were identified and a list of functional candidate genes within or next to these regions was created.
Key Words: digital dermatitis, sole ulcer, ssGWAS
