Genetic parameters for wool traits, live weight, and ultrasound carcass traits in Merino sheep

Title
Genetic parameters for wool traits, live weight, and ultrasound carcass traits in Merino sheep
Publication Date
2017
Author(s)
Mortimer, S I
Hatcher, S
Fogarty, N M
Van Der Werf, Julius H
( author )
OrcID: https://orcid.org/0000-0003-2512-1696
Email: jvanderw@une.edu.au
UNE Id une-id:jvanderw
Brown, Daniel
( author )
OrcID: https://orcid.org/0000-0002-4786-7563
Email: dbrown2@une.edu.au
UNE Id une-id:dbrown2
Swan, Andrew
( author )
OrcID: https://orcid.org/0000-0001-8048-3169
Email: aswan@une.edu.au
UNE Id une-id:aswan
Greeff, J C
Refshauge, G
Edwards, J E Hocking
Gaunt, G M
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
American Society of Animal Science
Place of publication
United States of America
DOI
10.2527/jas2016.1234
UNE publication id
une:22702
Abstract
Genetic correlations between 29 wool production and quality traits and live weight and ultrasound fat depth (FAT) and eye muscle depth (EMD) traits were estimated from the Information Nucleus (IN). The IN comprised 8 genetically linked flocks managed across a range of Australian sheep production environments. The data were from a maximum of 9,135 progeny born over 5 yr from 184 Merino sires and 4,614 Merino dams. The wool traits included records for yearling and adult fleece weight, fiber diameter (FD), staple length (SL), fiber diameter CV (FDCV), scoured color, and visual scores for breech and body wrinkle. We found high heritability for the major yearling wool production traits and some wool quality traits, whereas other wool quality traits, wool color, and visual traits were moderately heritable. The estimates of heritability for live weight generally increased with age as maternal effects declined. Estimates of heritability for the ultrasound traits were also higher when measured at yearling age rather than at postweaning age. The genetic correlations for fleece weight with live weights were positive (favor-able) and moderate (approximately 0.5 ± 0.1), whereas those with FD were approximately 0.3 (unfavorable). The other wool traits had lower genetic correlations with the live weights. The genetic correlations for FAT and EMD with FD and SL were positive and low, with FDCV low to moderate negative, but variable with wool weight and negligible for the other wool traits. The genetic correlations for FAT and EMD with postweaning weight were positive and high (0.61 ± 0.18 to 0.75 ± 0.14) but were generally moderate with weights at other ages. Selection for increased live weight will result in a moderate correlated increase in wool weight as well as favorable reductions in breech cover and wrinkle, along with some unfavorable increases in FD and wool yellowness but little impact on other wool traits. The ultrasound meat traits, FAT and EMD, were highly positively genetically correlated (0.8), and selection to increase them would result in a small unfavorable correlated increase in FD, moderately favorable reductions in breech cover and wrinkle, but equivocal or negligible changes in other wool traits. The estimated parameters provide the basis for calculation of more accurate Australian Sheep Breeding Values and selection indexes that combine wool and meat objectives in Merino breeding programs.
Link
Citation
Journal of Animal Science, 95(5), p. 1879-1891
ISSN
1525-3163
0021-8812
Start page
1879
End page
1891

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