Author
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Van Vleck, Lloyd |
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Submitted to: American Society of Animal Science
Publication Type: Abstract Only Publication Acceptance Date: 2/21/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Teaching, research and herd breeding applications may require calculation of breed additive contributions for direct and maternal genetic effects and fractions of heterozygosity associated with breed specific direct and maternal heterosis effects. These coefficients can be obtained from the first n rows of a pseudo numerator relationship matrix where the first n rows represent fractional contributions by breed to each animal or group representing a specific breed cross. The table begins with an n x n identity matrix representing pure breeds. Initial animals or representative crosses must be purebreds or two breed crosses. Parents of initial purebreds are represented by the corresponding column and initial two-breed cross progeny by the two corresponding columns of the identity matrix. After that, usual rules are used to calculate the n column entries corresponding to breeds for each animal. The n entries are fractions of genes expected to be contributed by each of the pure breeds and correspon to the breed additive direct fractions. Entries in the column corresponding to the dam represent breed additive maternal fractions. Breed specific direct heterozygosity coefficients are entries of an n x n matrix formed by the outer product of the two n by 1 columns associated with sire and dam of the animal. One minus sum of the diagonals represents total direct heterozygosity. Similarly, the n x n matrix formed by the outer product of columns associated with sire of dam and dam of dam contains breed specific maternal heterozygosity coefficients. These steps can be programmed to create covariates to merge with data. |