Genetics of meat quality and carcass traits and the impact of tenderstretching in two tropical beef genotypes

Title
Genetics of meat quality and carcass traits and the impact of tenderstretching in two tropical beef genotypes
Publication Date
2009
Author(s)
Wolcott, Matthew Lee
( author )
OrcID: https://orcid.org/0000-0001-6786-8742
Email: mwolcott@une.edu.au
UNE Id une-id:mwolcott
Johnston, David
( author )
OrcID: https://orcid.org/0000-0002-4995-8311
Email: djohnsto@une.edu.au
UNE Id une-id:djohnsto
Barwick, Stephen
Iker, CL
Thompson, John
Burrow, Heather M
( author )
OrcID: https://orcid.org/0000-0002-7989-0426
Email: hburrow2@une.edu.au
UNE Id une-id:hburrow2
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
CSIRO Publishing
Place of publication
Australia
DOI
10.1071/EA08275
UNE publication id
une:4478
Abstract
Meat quality and carcass traits were measured for 2180 feedlot finished Brahman (BRAH) and Tropical Composite (TCOMP) steers to investigate genetic and non-genetic influences on shear force, and other meat quality traits. Genetic and phenotypic correlations were estimated between carcass and meat quality traits, and with live animal measurements collected in steers from weaning to feedlot exit, and their heifer half-sibs up to their first mating, which were managed in Australia’s tropical or subtropical environments. Left sides of carcasses were tenderstretched (hung by the aitch-bone) while right sides were conventionally hung (by the Achilles tendon). Tenderstretching reduced mean shear force by 1.04 kg, and phenotypic variance by 77% of that observed in conventionally hung sides. Genotype differences existed for carcass traits, with TCOMP carcasses significantly heavier, fatter, with greater eye muscle area, and lower retail beef yield than BRAH. TCOMP had lower shear force, and higher percent intramuscular fat. Meat quality and carcass traits were moderately heritable, with estimates for shear force and compression of 0.33 and 0.19 for BRAH and 0.32 and 0.20 for TCOMP respectively. In both genotypes, estimates of heritability for carcass traits (carcass weight, P8 and rib fat depths, eye muscle area and retail beef yield) were consistently moderate to high (0.21 to 0.56). Shear force and compression were genetically correlated with percent intramuscular fat (r'g' = –0.26 and –0.57, respectively), and meat colour (r'g' = –0.41 and –0.68, respectively). For TCOMP, lower shear force was genetically related to decreased carcass P8 fat depth (r'g' = 0.51). For BRAH steers and heifers measured at pasture, fatness traits and growth rates were genetically correlated with shear force, although the magnitude of these relationships varied with time of measurement. Net feed intake was significantly genetically correlated with carcass rib fat depth (r'g' = 0.49), eye muscle area (r'g' = –0.42) and retail beef yield (r'g' = –0.61). These results demonstrate that selection to improve production and carcass traits can impact meat quality traits in tropically adapted cattle, and that genotype specific evaluations will be necessary to accommodate different genetic relationships between meat quality, carcass and live animal traits.
Link
Citation
Animal Production Science, 49(6), p. 383-398
ISSN
1836-5787
1836-0939
Start page
383
End page
398

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