Abstract
The selection results in Miyazaki herd are presented in this report. The breeding herd averaged 44.1 females and 11.0 males per generation, and increases of inbreeding and interse relationship in the coures of the experiment were extimated to be 7.7% and 21.3%, respectively. The mean standardized selection differentials were 1.15 for males and 0.61 for females.
The realized heritabilities estimated from the regressions of responses to cumulative selection differentials in the selection index were 0.28±0.04 for males and 0.35±0.03 for females and these values well agreed with the estimates in the Iwate herd and the expected heritability. The realized values of correlated selection responses of the component traits of the index per generation were -2.5g for average daily gain., -0.049cm for backfat thickness, 0.54cm2 for loin-eye area and 0.09% for percent ham. The responses of the three carcass traits were higher than the expected ones, but the average daily gain showed no responses. The causes for the lack of response in daily gain were discussed in comparirison with the parameters estimated in the experimental herd and those used for the construction of the selection index.
