Including feed intake in the estimation of breeding value of pigs
1988
Hong, K.C. (Korea Univ., Seoul (Korea R.). Coll. of Agriculture)
Daily feed intake decreased by 4, 8 and 1% in the breeds German landrace, Belgian landrace and pietrain from 1972-75 to 1979-82, respectively. This situation suggests to pay more attention to feed intake in breeding value estimation and selection. Decreased feed intake is due to the unfavourable genetic correlations of -0, 50, 0.50 and 0.40 resp. between feed intake and lean meat content, meat-to-fat ratio and backfat thickness. Direct inclusion of feed intake in the breeding value is difficult, since the economic weight of this trait is questionable. In the present study, effects of using the restricted selection index for feed intake on the expected genetic gains in other traits are investigated. Restriction of feed intake decreases the expected genetic gain in lean meat content to about 53%, whereas that in the daily gain increases to about 130% the various breeding value variants studied. As far as total genetic gain is concerned, restriction of feed intake affects this only little. Because there is no economic weight for feed intake, the restriction of feed intake in the selection index can be considered until the development of reliable measuring methods for the traits lean tissue growth rate (LTGR) and lean tissue feed conversion (LTFC)
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