Boldman K G, Famula T R
J Dairy Sci. 1985 Aug;68(8):2052-7. doi: 10.3168/jds.S0022-0302(85)81067-5.
Data on 13 traits of 11,260 progeny of 775 sires in the Carnation Genetics linear type appraisal program were analyzed to determine the association between sire dystocia transmitting ability and progeny linear type traits. Mean linear type scores ranged from 25.0 to 29.8 on a scale of 1 to 50. Parity, stage of lactation, and interactions of evaluator by parity and evaluator by stage were sources of variation for most traits. First quartile (easy) and fourth quartile (most difficult) sires grouped by dystocia transmitting ability differed in daughter linear type scores for stature, dairy character, rump angle, center ligament, udder depth, teat length, teat placement, and rump width. Differential use of easy calving bulls on heifers might result in progeny with lower type scores for stature, dairy character, rump angle, legs, and rump width. Average type scores differed by less than 1 unit for all traits, indicating little correlated response in linear type traits through use of bulls whose progeny are born with least difficulty.