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Full-Text Articles in Animal Sciences
Effects Of Selection Of Data On Estimates Of Breeding Values By Three Methods For Litter Size, Backfat, And Average Daily Gain In Swine, T. E. Long, R. K. Johnson, J. W. Keele
Effects Of Selection Of Data On Estimates Of Breeding Values By Three Methods For Litter Size, Backfat, And Average Daily Gain In Swine, T. E. Long, R. K. Johnson, J. W. Keele
Department of Animal Science: Faculty Publications
Estimated breeding value was calculated based on individual phenotype (SP), an index of individual phenotype and full- and half-sib family averages (SI), or Best Linear Unbiased Rediction (BLUP). Traits considered were litter size (LS), backfat (BF), and ADG. Estimated breeding values were calculated using all data and after deletion of the poorest 5, 10, 15, or 20% of the records for BF and ADG, or 4.8, 8, 13, or 21% of the records for LS. When ail data were used, expected genetic gain from BLUP was greater than for SP by 22,7, and 31% and greater than for SI by …
Aspects Of Selection For Performance In Several Environments With Heterogeneous Variances, D. J. Garrick, L. Dale Van Vleck
Aspects Of Selection For Performance In Several Environments With Heterogeneous Variances, D. J. Garrick, L. Dale Van Vleck
Department of Animal Science: Faculty Publications
Dairy cattle evaluation schemes routinely assume homogeneous variance with respect to environment. Increasing evidence suggests the presence of systematic changes in variance components associated with mean level of performance. Best linear unbiased prediction procedures that account for heterogeneity are reviewed. The consequences of incorrectly assuming homogeneity for evaluation are demonstrated for a progeny test and an artificial breeding program that screens dams of sires from heterogeneous populations. Selection assuming homogeneity can be very efficient when heritability, and therefore accuracy of selection, is greatest in the more variable environment. Conversely, appreciable reduction in response results when heritability is greater in the …