Opportunities for genetic improvement of lamb survival

Title
Opportunities for genetic improvement of lamb survival
Publication Date
2010
Author(s)
Brien, Forbes Donald
Hebart, M L
Robertson, M W
Hinch, Geoffrey
( author )
OrcID: https://orcid.org/0000-0003-4731-865X
Email: ghinch@une.edu.au
UNE Id une-id:ghinch
Geenty, Kennett
Van Der Werf, Julius H
( author )
OrcID: https://orcid.org/0000-0003-2512-1696
Email: jvanderw@une.edu.au
UNE Id une-id:jvanderw
Smith, D H
Hocking Edwards, J E
Greeff, J C
Hart, K W
Refshauge, G
Bird-Gardiner, T L
Gaunt, G
Behrendt, R
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
CSIRO Publishing
Place of publication
Australia
DOI
10.1071/AN10121
UNE publication id
une:7466
Abstract
Data on lamb survival and associated traits involving records from 15 192 lambs, 6308 dams and 284 sires from the Sheep CRC's Information Nucleus were studied. Lamb survival to 3 days of age and to weaning was 85 and 80%, respectively, and heritability (±s.e.) was 0.014 ± 0.010 and 0.010 ± 0.010, respectively. Of the 14 traits recorded at birth, time taken for the lamb to bleat, rectal temperature and crown–rump length had the highest genetic correlations with lamb survival to weaning (–0.43 ± 0.32, 0.56 ± 0.33 and –0.38 ± 0.36, respectively). Under selection for a multi-trait objective including net reproduction rate (but not lamb survival), survival was predicted to decline genetically by 0.25 lambs weaned per 100 lambs born.year, although this was reversed to a gain of 0.20 lambs weaned per 100 lambs born.year by including the trait in the breeding objective and using 50 half-sib and 50 progeny records per selection candidate. Accuracy of selection for lamb survival was improved to 0.735 with a selection index of lamb survival to weaning, lamb ease, birth coat score, time taken to bleat, rectal temperature and crown–rump length, with the addition of 50 half-sibs and 50 progeny records per candidate. Our results suggest that unless actively incorporated into breeding objectives, lamb survival may genetically decline; however, gains are possible with direct selection using half-sib and progeny records. The addition of indirect selection criteria for lamb survival can further improve accuracy, up to 93.4%, but requires further investigation.
Link
Citation
Animal Production Science, 50(12), p. 1017-1025
ISSN
1836-5787
1836-0939
Start page
1017
End page
1025

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