Production Traits and Visual Scores of Tested Boars

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Abstract
Production records and visual scores were analyzed for 1072 boars tested at the Indiana Boar Test Station during a 3-year period. Similar production records and visual scores were observed for boars consigned by old and new breeders, and for boars tested in either full-sib or half-sib pairs. Adjusted backfat thickness, adjusted loin eye area and index measurements were similar for fall and spring tested boars. Fall tested boars grew faster but required more feed than spring tested boars. For visual scores, spring tested boars scored higher in body capacity, front leg soundness and breed type; and fall tested boars scored higher in bone size and underline. Early group boars within each test season, spring or fall, were younger in initial age, grew faster spending fewer days on test, were more efficient (lower F/G), had lower adjusted ages, and received higher visual scores for bone size, breed type and total visual score. Index qualified and non-index qualified, classified according to National Swine Improvement Federation (NSIF) procedures, had similar visual scores. Index qualified boars were superior in all production traits except initial weight, adjusted backfat thickness and adjusted loin-eye area. Soundness class and index status × soundness class interaction effects were nonsignificant sources of variation for all production traits. These results indicate that structurally unsound boars and/or boars with unacceptable underlines can be visually “screened” for these traits as recommended by NSIF. Boars with heavier initial weights received higher conformation and total visual scores, were fatter, gained faster and were less efficient. Boars with older initial ages received lower body length and body capacity scores, had greater test average daily gains, were on test fewer days but had larger adjusted age values. Copyright © 1979. American Society of Animal Science . Copyright 1979 by American Society of Animal Science.