Remodelling the genetic evaluation of NFI in beef cattle - Part 2: Shortening the length of the feed intake test

Title
Remodelling the genetic evaluation of NFI in beef cattle - Part 2: Shortening the length of the feed intake test
Publication Date
2023-07-26
Author(s)
Vargovic, L
( author )
OrcID: https://orcid.org/0000-0001-8963-1287
Email: lvargov2@une.edu.au
UNE Id une-id:lvargov2
Moore, K L
( author )
OrcID: https://orcid.org/0000-0001-6779-0148
Email: kmoore7@une.edu.au
UNE Id une-id:kmoore7
Johnston, D J
( author )
OrcID: https://orcid.org/0000-0002-4995-8311
Email: djohnsto@une.edu.au
UNE Id une-id:djohnsto
Jeyaruban, G M
( author )
OrcID: https://orcid.org/0000-0002-0231-0120
Email: gjeyarub@une.edu.au
UNE Id une-id:gjeyarub
Girard, C J
( author )
OrcID: https://orcid.org/0000-0003-0542-7073
Email: cgirard@une.edu.au
UNE Id une-id:cgirard
Cook, J
( author )
OrcID: https://orcid.org/0000-0002-7405-500X
Email: jcook8@une.edu.au
UNE Id une-id:jcook8
Torres-Vazquez, J A
( author )
OrcID: https://orcid.org/0000-0001-6965-6065
Email: torresva@une.edu.au
UNE Id une-id:torresva
Miller, S P
( author )
OrcID: https://orcid.org/0000-0001-5273-352X
Email: smille66@une.edu.au
UNE Id une-id:smille66
Editor
Editor(s): Hatcher, Sue
Type of document
Conference Publication
Language
en
Entity Type
Publication
Publisher
Association for the Advancement of Animal Breeding and Genetics (AAABG)
Place of publication
Armidale, Australia
UNE publication id
une:1959.11/56136
Abstract

BREEDPLAN net feed intake (NFI) EBV is derived from a phenotypic regression based on a 70-day feed intake test. Genetic NFI (NFIg) EBVs have been proposed as an alternative EBV and this recent development may also allow for a shortened feed intake test period. This study used feed intake records of 3,088 Angus steers from the full 70-day test and compared them to daily feed intake (DFI) from shortened test periods. Results showed DFI from shortened test periods had similar means but increased phenotypic variation. Phenotypic correlation with DFI from the full test period decreased as the test period decreased in weekly intervals and ranged between 0.75 and 0.99. NFIg EBVs were predicted using DFI from different length tests. The mean of all NFIg EBVs was close to zero, but the EBV standard deviation increased as the test period decreased. Pearson correlations between NFIg EBVs from a full test period and reduced test periods ranged between 0.73 and 0.99, the regression slope of NFIg from reduced test periods on NFIg from the full test period ranged between 0.73 and 0.95, and the bias ranged between 0.00 and 0.02. These results indicate that as the test period decreases, the spread of EBVs increases, resulting in extreme animals having overestimated NFIg EBVs. A shortened DFI test period could be used to estimate NFIg EBVs.

Link
Citation
Proceedings of the Association for the Advancement of Animal Breeding and Genetics, v.25, p. 386-389
ISSN
1328-3227
Start page
386
End page
389

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