Bias in genetic evaluation using random regression test-day model
The effect of an upgraded Finnish evaluation model on bias in estimated breeding values for protein yield was investigated. Evaluations based on repeatability animal model and on random regression test-day model without and with heterogeneous variance adjustment were compared. Comparisons were based...
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Format: | Article |
Language: | English |
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Scientific Agricultural Society of Finland
2008-12-01
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Series: | Agricultural and Food Science |
Online Access: | https://journal.fi/afs/article/view/5871 |
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author | M. LIDAUER E.A. MÄNTYSAARI |
author_facet | M. LIDAUER E.A. MÄNTYSAARI |
author_sort | M. LIDAUER |
collection | DOAJ |
description | The effect of an upgraded Finnish evaluation model on bias in estimated breeding values for protein yield was investigated. Evaluations based on repeatability animal model and on random regression test-day model without and with heterogeneous variance adjustment were compared. Comparisons were based on the average difference between pedigree indices and the future estimated breeding values, based on own or on daughter performance records. This was defined as empirical bias. The pedigree indices were computed from reduced data sets where four years of the most recent data were excluded. Results showed an upward bias in the protein yield pedigree indices for Ayrshire young sires of 2.2 kg, 2.5 kg and 1.8 kg from the repeatability animal model, random regression test-day model and random regression test-day model with heterogeneous variance adjustment, respectively. Pedigree indices for daughters of young sires were upward biased, whereas pedigree indices for daughters of proven sires were slightly underestimated when heterogeneous variance was not accounted. Inclusion of test-day yields from the fourth lactation onwards increased the bias. Moving from repeatability animal model to random regression test-day model did not reduce the bias, whereas adjustment of heterogeneous variance reduced bias.; |
first_indexed | 2024-04-12T20:35:32Z |
format | Article |
id | doaj.art-f55c0e2952454d38b9fa5c73fd3c29ce |
institution | Directory Open Access Journal |
issn | 1459-6067 1795-1895 |
language | English |
last_indexed | 2024-04-12T20:35:32Z |
publishDate | 2008-12-01 |
publisher | Scientific Agricultural Society of Finland |
record_format | Article |
series | Agricultural and Food Science |
spelling | doaj.art-f55c0e2952454d38b9fa5c73fd3c29ce2022-12-22T03:17:38ZengScientific Agricultural Society of FinlandAgricultural and Food Science1459-60671795-18952008-12-01162Bias in genetic evaluation using random regression test-day modelM. LIDAUERE.A. MÄNTYSAARIThe effect of an upgraded Finnish evaluation model on bias in estimated breeding values for protein yield was investigated. Evaluations based on repeatability animal model and on random regression test-day model without and with heterogeneous variance adjustment were compared. Comparisons were based on the average difference between pedigree indices and the future estimated breeding values, based on own or on daughter performance records. This was defined as empirical bias. The pedigree indices were computed from reduced data sets where four years of the most recent data were excluded. Results showed an upward bias in the protein yield pedigree indices for Ayrshire young sires of 2.2 kg, 2.5 kg and 1.8 kg from the repeatability animal model, random regression test-day model and random regression test-day model with heterogeneous variance adjustment, respectively. Pedigree indices for daughters of young sires were upward biased, whereas pedigree indices for daughters of proven sires were slightly underestimated when heterogeneous variance was not accounted. Inclusion of test-day yields from the fourth lactation onwards increased the bias. Moving from repeatability animal model to random regression test-day model did not reduce the bias, whereas adjustment of heterogeneous variance reduced bias.;https://journal.fi/afs/article/view/5871 |
spellingShingle | M. LIDAUER E.A. MÄNTYSAARI Bias in genetic evaluation using random regression test-day model Agricultural and Food Science |
title | Bias in genetic evaluation using random regression test-day model |
title_full | Bias in genetic evaluation using random regression test-day model |
title_fullStr | Bias in genetic evaluation using random regression test-day model |
title_full_unstemmed | Bias in genetic evaluation using random regression test-day model |
title_short | Bias in genetic evaluation using random regression test-day model |
title_sort | bias in genetic evaluation using random regression test day model |
url | https://journal.fi/afs/article/view/5871 |
work_keys_str_mv | AT mlidauer biasingeneticevaluationusingrandomregressiontestdaymodel AT eamantysaari biasingeneticevaluationusingrandomregressiontestdaymodel |