except G4 generation. Across generations, the genetic correlation was
high (0.942) and was not also significantly different from unity (z=
−0.83, P>0.05).
3.3. Response to selection
The least squares means of the square root transformed individual
body weight per generation are given in Table 6. The realised genetic
gain from generation G2 to G3 (0.169 g0.5) was significantly different
from zero (Pb0.05), while the other three realised genetic gains were
not significantly different from zero (P>0.05). The accumulated genetic
gain was 12.34% after performing four selections, or 3.09% per generation.
The predicted genetic gains in harvest body weight per generation
estimated from two sets of genetic parameters, Set 1 obtained from
five within-generation datasets and Set 2 obtained from the acrossgeneration
dataset, are shown in Table 7. The mean breeding values
increased over generations for both sets of parameters. The predicted
genetic gains using Set 2 were markedly lower than those predicted
using Set 1. The total predicted genetic gains for Set 1 and Set 2 parameters
relative to the base population were 0.414 g0.5 and
0.283 g0.5, respectively. The predicted accumulated gains for Set 1 and Set 2 parameters over the four generations of selection expressed
as proportions were 9.05% and 6.20%, respectively. After performing
four selections, the genetic selection response expressed in genetic
standard deviation units were 1.89 and 1.29 in Set 1 and Set 2,
respectively.