Ultrasonic evaluation of carcass traits in young Brangus bulls
Date
1996
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Texas A&M University
Abstract
In Phase 1, growth performance and serial ultrasound data were collected and analyzed on 194 Brangus bulls. Ultrasound data were collected at weaning, during a 140 day gain test, at yearling and at a post-yearling time period. Principles of the allometric equation were used and following logarithmic transformation of the pooled serial data, the linear regression of ULMA on WT yielded a growth coefficient value of .6869. The coefficient value .6869 was used to calculate non-linear ratios (K) of ULMA to WT using the formula K = ULMA / WT.6869 for each ultrasound test interval. K ratios were more highly correlated with ULMA (r = .79 to .83) than were corresponding ratios of longissimus area per 45.4kg of live weight(LMACWT)(r=.50 to .66). K ratios were not highly correlated with age (r =-. I 1 to .23). Correlations between K ratios and WT were at least 50% less (r =-.23 to .09) than corresponding LMACWT ratios (r =-.28 to-.46).In Phase 11, growth performance and yearling ultrasound data were collected and analyzed on 1,831 Brangus bulls for the purpose of validating the results in phase 1. K ratios were highly correlated with LMACWT and ULMA (r = .97 and .83, respectively). K ratios had significantly lower correlations with WT (r =-. 17) and yearling age (YAGE) (r = -. I 1) compared with the association of LMACWT with WT and YAGE (r =-.43 and .26, respectively). K ratios calculated using a growth coefficient of .50 resulted in lower correlations with WT and YAGE (r =-. 0 1 and-. 0 8, respectively) and a high correlation (r = .9 1) with ULMA. Results indicated that allometric equations can be developed and used to calculate ratios of ULMA and WT that have greater independence from the effects of weight and age than corresponding linear ratios and may provide a more appropriate measure of evaluating ULMA data in purebred breeding programs where carcass traits are included as part of the selection process.
Description
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Includes bibliographical references.
Issued also on microfiche from Lange Micrographics.
Includes bibliographical references.
Issued also on microfiche from Lange Micrographics.
Keywords
animal science., Major animal science.