Body dimensions and carcass measurements of cattle selected for postweaning gain fed two different diets

Abstract

Genetic and phenotypic parameters among nine body dimensions and two measures of growth rate were estimated from measurements on 709 Angus and Hereford bulls and heifers born in 1984 and 1985. Height and width at hips, height at withers, body length, girth, head length and width, muzzle width, and cannon bone circumference were measured at weaning and again after 168-d postweaning gain tests. The cattle were from the final two calf crops of a 20-yr study to examine the response to selection for postweaning gain when fed either a high-concentrate diet or an all-hay diet. Sources of variation included year of birth, breed, sire within breed, diet, age of dam, and the linear regression on calf age. Parameter estimates among the body dimensions and carcass measurements were also calculated using a subsample of 318 Hereford and Angus bulls fed until they achieved > or = 7 mm of subcutaneous fat. Yearling measurements from calves fed the high-concentrate diet were larger than those from calves fed the all-hay diet. Sire within breed, age of dam, and the regression on age of calf affected all measurements (P < .001) at both measurement times. Dietary energy concentration influenced all body measurements taken at the end of test. Heritabilities of all body measurements were moderate to high. The highest genetic correlations with gain were for cannon bone circumference, body length, and heart girth. The heritabilities of all body dimensions were sufficient to indicate that selection progress was possible, but the low genetic correlations with gain and carcass traits suggested that this may not be desirable.

The estimation of live weight from body measurements in Yankasa sheep

“…However, the maintenance of birth growth advantage to later ages (Adu and Ngere, 1979;Tuah and Baah, 1985), as observed herein, is supported by the maternal ability of ewes when suckling heavier lambs which tend to be male (Newman et al, 1993) or of lamb's subsequent ability to eat grass. These differences between male and female lambs were similar to those reported in beef cattle (Gilbert et al, 1993;Afolayan et al, 2002a,b). In those reports, steers were heavier, taller and bigger in girth; more muscled but with less fat compared to heifers both at weaning and post-weaning ages.…”

“…However, feedlot trials with beef cattle crossbreds (Rutley et al, 1995) showed that weight, height, fat depth and visual muscle score (score developed by McKiernan, 1990) could be sufficient to describe variation in feedlot performance of the most economically important traits (average daily gain, carcass weight, fat depth and saleable beef yield). In the same species, objective body dimensions and measures of muscular development were shown to serve either to supplement body weight as a measure of productivity (Afolayan et al, 2002a,b) or as predictors of some less visible characteristics (Gilbert et al, 1993). In addition, body measurements could be used to predict live weight fairly well in the situation where weighbridges are not available (Berge, 1977;Buvanendran et al, 1980;Goonerwardene and Sahaayuraban, 1983).…”

Breed variation and genetic parameters for growth and body development in diverse beef cattle genotypes

“…Few studies included additional body measurements like hip height and body length mostly at post-weaning (Gilbert et al, 1993;Vargas et al, 2000). In this study, the direct heritability for weaning weight (18%, Table 2) was lower than both the unweighted (35% and 27%) and weighted (31% and 24%) mean estimates reviewed from over 170 papers (Koots et al, 1994a).…”

“…However, higher estimates were obtained for weaning height in the studies of Vargas et al (2000) on a single breed (Brahman) measured at a much older age (18 months) and Gilbert et al (1993) on Hereford and Angus breeds. Apart from the work of Gilbert et al (1993) that provided heritability estimates for weaning and post-weaning length as an additional body dimensional trait, the mostly moderate estimates for body length (19 to 25%) and girth (9 to 32%) from weaning (250) day to 600-day of age herein represents the first Australian estimates for beef cattle breed types for genetic description of animal size. Gutierrez and Goyache (2002) were of the opinion that standard breed conformation described by skeletal and muscular development could be effectively used to evaluate the animal's productive ability.…”

“…Gilbert et al (1993) also proposed the use of body dimensions or linear measurements either to supplement body weight as a measure of productivity or as predictors of some less visible characteristics. The aim of this study was to estimate the genetic variances for growth and objectively measured development (e.g.…”