title: Multiple regression and principal components analysis of puberty and growth in cattle.
abstract: Multiple regression and principal components analyses were employed to examine relationships among pubertal and growth characters. Records used were from 424 bulls and 475 heifers produced by a diallel mating of Angus, Brahman, Hereford, Holstein and Jersey breeds. Characters studied were age, weight and height at puberty and measurements of weight and hip height from 9 to 21 mo of age; pelvic measurements of heifers also were included. Measurements of weight and height near 1 yr of age were related most highly to pubertal age, weight adn height. Larger size near 1 yr of age was associated with younger, larger animals at puberty. Growth rate was associated with pubertal characters before, but not after, adjustment for effects of breed-type. Principal components of the variation of pubertal and growth characters among animals were strongly related to both weight and height. The majority of the variation among breed-types was due to height. Characteristic vectors of principal components describing the variation of bulls and heifers were strikingly similar. The variance-covariance structure of pubertal characters was essentially the same for both sexes even though the mean values of the characters differed.
authors.affiliation: Dept. of Anim. Sci., Texas Agricultural Experiment Station, College Station 77843.
authors.forename: J F
authors.initials: JF
authors.lastname: Baker
authors.forename: T S
authors.initials: TS
authors.lastname: Stewart
authors.forename: C R
authors.initials: CR
authors.lastname: Long
authors.forename: T C
authors.initials: TC
authors.lastname: Cartwright
mesh_terms: D000818:Animals; D001824:Body Constitution; D001835:Body Weight; D002417:Cattle / Q000254:growth & development*; D005260:Female; D008297:Male; D012044:Regression Analysis; D012741:Sexual Maturation; D013045:Species Specificity