Abstract
Lameness is an animal welfare issue that incurs substantial financial and environmental costs. This condition is commonly caused by digital dermatitis (DD), sole ulcers (SU), and white line disease (WLD). Susceptibility to these three foot disorders is due in part to genetics, indicating that genomic selection against these foot lesions can be used to reduce lameness prevalence. It is unclear whether selection against foot lesions will lead to increased susceptibility to other common diseases such as mastitis and metritis. Thus, the aim of this study was to determine the genetic correlation between causes of lameness and other common health disorders to identify loci contributing to the correlation. Genetic correlation estimates between SU and DD and between SU and WLD were significantly different from zero (p < 0.05), whereas estimates between DD and mastitis, DD and milk fever, and SU and metritis were suggestive (p < 0.1). All five of these genetic correlation estimates were positive. Two-trait genome-wide association studies (GWAS) for each of these five pairs of traits revealed common regions of association on BTA1 and BTA8 for pairs that included DD or SU as one of the traits, respectively. Other regions of association were unique to the pair of traits and not observed in GWAS for other pairs of traits. The positive genetic correlation estimates between foot disorders and other health disorders imply that selection against foot disorders may also decrease susceptibility to other health disorders. Linkage disequilibrium blocks defined around significant and suggestive SNPs from the two-trait GWAS included genes and QTL that were functionally relevant, supporting that these regions included pleiotropic loci.
Highlights
Abnormal gait or posture in a cow are considered indicators of lameness and signifies pain and discomfort
Significant and suggestive single nucleotide polymorphism (SNP) were detected in the same regions on BTA1 and BTA8 for two-trait genome-wide association studies (GWAS) datasets that had digital dermatitis (DD) and sole ulcers (SU) as one of the traits, respectively, suggesting that DD and SU were driving the association in these genomic regions
A genomic relatedness matrix calculated from SNP genotypes was used to estimate genetic correlation between individual foot disorders (DD, SU, and white line disease (WLD)) and other health disorders
Summary
Abnormal gait or posture in a cow are considered indicators of lameness and signifies pain and discomfort. Lameness is the second most prevalent disease after mastitis and the third most common reason for culling after mastitis and infertility (USDA, 2018). Lameness raises welfare concerns, and has economic and environmental consequences. Premature culling, and reduced milk production associated with lameness reduces the efficiency of resource use, as resources used for the cow are invested over a less productive and shorter lifetime, inflating the environmental costs per unit of milk by 14 (1.5%) kg CO2 equivalents per ton of fat-and-proteincorrected milk, on average (of DD, SU, and WLD combined) (Mostert et al, 2018)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
