Divergent selection for postweaning feed conversion in Angus beef cattle: III. Linear body measurements of progeny.

Postweaning performance data were obtained on 401 group-fed, purebred Angus calves from 24 selected sires (12 high- and 12 low-feed-conversion sires) from 1983 through 1986 at the Northwestern Branch of the Ohio Agricultural Research and Development Center. Body measurements of progeny were taken from 1983 through 1986 for hip height and backfat, whereas others, except chest measurements (depth and width) that were available only in 1985, were taken from 183 progeny born in 1985 and 1986. The objective of this portion of the study was to determine whether differences in linear body measurements exist between progeny of high- and low-feed-conversion sires. Differences between progeny of high- and low-feed-conversion sires tended to exist (P < .10) for heart girth (176.3 +/- 1.2 vs 173.2 +/- 1.2 cm) and were significant for backfat thickness (.94 +/- .01 vs .87 +/- .02 cm). No significant differences were observed for hip height (115.3 +/- .5 vs 115.5 +/- .5 cm), chest depth (58.8 +/- .6 vs 57.4 +/- .6 cm), chest width (44.4 +/- .5 vs 44.0 +/- .5 cm), head width (21.2 +/- .2 vs 21.1 +/- .2 cm), head length (42.4 +/- .3 vs 41.6 +/- .3 cm), muzzle circumference (41.0 +/- .4 vs 41.6 +/- .3 cm), length between hooks and pins (46.7 +/- .5 vs 46.2 +/- .5 cm), length between shoulder and hooks (94.9 +/- 1.0 vs 93.1 +/- 1.0 cm), or volume (361,199 +/- 4,885 vs 352,718 +/- 5,026 cm3).