title: Alternative parameterizations of relatedness in whole genome association analysis of pre-weaning traits of Nelore-Angus calves.
abstract: Gestation length, birth weight, and weaning weight of F2 Nelore-Angus calves (n = 737) with designed extensive full-sibling and half-sibling relatedness were evaluated for association with 34,957 SNP markers. In analyses of birth weight, random relatedness was modeled three ways: 1) none, 2) random animal, pedigree-based relationship matrix, or 3) random animal, genomic relationship matrix. Detected birth weight-SNP associations were 1,200, 735, and 31 for those parameterizations respectively; each additional model refinement removed associations that apparently were a result of the built-in stratification by relatedness. Subsequent analyses of gestation length and weaning weight modeled genomic relatedness; there were 40 and 26 trait-marker associations detected for those traits, respectively. Birth weight associations were on BTA14 except for a single marker on BTA5. Gestation length associations included 37 SNP on BTA21, 2 on BTA27 and one on BTA3. Weaning weight associations were on BTA14 except for a single marker on BTA10. Twenty-one SNP markers on BTA14 were detected in both birth and weaning weight analyses.
authors.affiliation: Department of Animal Science , Texas A&M University , College Station, TX , USA .
authors.forename: David G
authors.initials: DG
authors.lastname: Riley
authors.affiliation: Department of Animal Science , Texas A&M University , College Station, TX , USA .
authors.forename: Clare A
authors.initials: CA
authors.lastname: Gill
authors.affiliation: Department of Animal Science , Texas A&M University , College Station, TX , USA .
authors.forename: Andy D
authors.initials: AD
authors.lastname: Herring
authors.affiliation: Department of Animal Science , Texas A&M University , College Station, TX , USA .
authors.forename: Penny K
authors.initials: PK
authors.lastname: Riggs
authors.affiliation: Department of Animal Science , Texas A&M University , College Station, TX , USA .
authors.forename: Jason E
authors.initials: JE
authors.lastname: Sawyer
authors.affiliation: Department of Animal Science , Texas A&M University , College Station, TX , USA .
authors.forename: James O
authors.initials: JO
authors.lastname: Sanders
keywords: Nelore; birth weight; gestation length; weaning weight; whole genome association