Table 2 Estimated heritabilities and temporal trends in mean predicted breeding value by birth year (βG) from Model A fitted by REML.

From: Genetic improvement of speed across distance categories in thoroughbred racehorses in Great Britain

Distance

h2

χ20,1

P

βG

βG / βP

Sprint

0.124 (0.006)

1990.8

<0.001

0.009

60%

Middle

0.122 (0.007)

1913.4

<0.001

0.006

55%

Long

0.074 (0.012)

115.04

<0.001

0.001

17%

  1. Values in parentheses denote standard errors. Likelihood ratio tests of VA are also shown. For comparison βG is also presented as a proportion of rates of phenotypic change (βP) reported previously. Units of βG and βP are yards.s−1.year−1.
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