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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Genomics and Improvement Laboratory » Research » Publications at this Location » Publication #408995
Research Project: Increasing Accuracy of Genomic Prediction, Developing Algorithms, Selecting Markers, and Evaluating New Traits to Improve Dairy Cattle

Location: Animal Genomics and Improvement Laboratory

Title: Inheritance of a new mutation affecting muscle weakness within a common haplotype in Holsteins

Author
item Al-Khudhair, Ahmed
item NICOLAZZI, EZEQUIEL - Council On Dairy Cattle Breeding
item Vanraden, Paul
item Null, Daniel
item Neupane, Mahesh
item DECHOW, CHAD - Pennsylvania State University

Submitted to: Interbull Annual Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 9/26/2023
Publication Date: 12/13/2023
Citation: Al-Khudhair, A.S., Nicolazzi, E.L., Van Raden, P.M., Null, D.J., Neupane, M., Dechow, C.D. 2023. Inheritance of a new mutation affecting muscle weakness within a common haplotype in Holsteins. Interbull Bulletin. 59:202-206.

Interpretive Summary:

Technical Abstract: A haplotype associated with calf recumbency and mortality having a recessive effect but apparent incomplete penetrance was previously linked to the end of chromosome 16 (78.7 to 80.7Mbp). Genotype analysis of 5.6 million Holsteins indicated that the haplotype was common and traced back to 1952, with a key ancestor born in 1984 (HOUSA1964484, Southwind) identified from chip genotypes as homozygous for the suspect haplotype. Sequence data from Southwind, an affected calf, and the sire of the affected calf were scanned for candidate mutations. A mutation in the CACNA1s gene causing symptoms of recumbency (lately termed Holstein Early Onset Muscle Weakness; HMW) was homozygous in the affected calf and heterozygous in the calf’s sire and Southwind. Improved methods for using pedigree to track new mutations within existing haplotypes were developed, and gene tests for the mutation were also included. For new mutations within existing common haplotypes, determining carrier status without gene tests is difficult, even with accurate pedigrees when the original haplotype has a high frequency.