For small and isolated populations, genetic drift or mating between relatives may increase homozygosity, and then results in a reduction of the mean phenotypic value
of traits associated with fitness, such as inbreeding depression (Charlesworth & Charlesworth 1987, Falconer & Mackay 1996).
2] of 90%, 4 years of successive harvests to assess the phenotypic value
of the progenies would be necessary.
where, FC = average phenotypic value
of the reciprocal crosses, P = average phenotypic value
of two parental populations.
However, as racing Thoroughbreds have multiple records for race time under different conditions and environmental factors, race time alone is not suitable as phenotypic value
for genome-wide association studies (GWAS).
Selection was made based on the true breeding value (relative weights for each trait should be entered into the program via a parameter file), phenotypic value
(relative weight needed), and estimated breeding value (relative weight needed).
Allele A is defined to decrease the phenotypic value
and allele B is defined to increase the phenotypic value
(or favourable allele).
Where y is the vector of phenotypic values
, X and Z are the design matrices, b and u are vectors of fixed and random effects, respectively.
Changes in phenotypic values
of the traits are shown in Table 1, and the selection differentials in the observed scales were provided.
The parameters of elementary statistics (means and variances) of phenotypic values
were obtained using the SAS procedure (SAS, 1996).
To maximize the sample size for allelic frequency comparison, medium phenotypic values
were used to divide the high and low phenotypic groups in the MCA/MSU cattle.
of quantitative traits and quantitative traits loci affecting body weight and average daily gain Trait (unit) (1) Phenotypic values
n Mean SD BW-0 (g) 359 34.
For fat and protein content, a low decrease in phenotypic values
was found, probably associated with negative correlations between milk yield and milk composites (see Oravcova et al.