Estimating heritability of subjectively assessed ostrich leather quality traits using threshold models

A Englebrecht; S W P Cloete; Kim L Bunter; J B van Wyk

Estimating heritability of subjectively assessed ostrich leather quality traits using threshold models

A Englebrecht
, S W P Cloete
, Kim L Bunter
, J B van Wyk

Animal Genetics and Breeding Unit

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › peer-review

Abstract

Several ostrich leather traits cannot be assessed objectively within the present industry structure. A subjective scoring system was devised to allow the assessment of several qualitative leather traits for the estimation of genetic parameters. Nodule size and shape, along with the presence of hair follicles and pitting damage were scored on linear scales from 1 to 9 on 1021 processed ostrich skins. The data were analysed together with live weight and skin size using threshold-linear animal models, with compression of categories where required. Heritability estimates were 0.44 for live weight, 0.33 for skin size, 0.46 for nodule size, 0.33 for nodule shape, 0.49 for hair follicles and 0.15 for pitting. The 95% highest posterior density confidence intervals for all variance components excluded zero. The quantitative slaughter traits were favourably related to nodule shape and nodule size, while the presence of hair follicles or pitting was not significantly related to the other traits on a genetic level. Sufficient genetic variation was demonstrated to allow sustained genetic progress for objective and subjectively assessed traits.

Original language	English
Title of host publication	Proceedings of the Association for the Advancement of Animal Breeding and Genetics
Editors	Alex Safari, Bill Pattie, Barrie Restall
Place of Publication	Armidale, Australia
Publisher	Association for the Advancement of Animal Breeding and Genetics (AAABG)
Pages	548-551
Volume	18
ISBN (Print)	9780646521039
Publication status	Published - 2009
Event	AAABG 2009: 18th Conference of the Association for the Advancement of Animal Breeding and Genetics - Barossa Valley, Australia Duration: 27 Sept 2009 → 2 Oct 2009

Conference

Conference	AAABG 2009: 18th Conference of the Association for the Advancement of Animal Breeding and Genetics
City	Barossa Valley, Australia
Period	27/09/09 → 2/10/09

Keywords

Animal Breeding

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https://hdl.handle.net/1959.11/5253

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Englebrecht, A., Cloete, S. W. P., Bunter, K. L., & van Wyk, J. B. (2009). Estimating heritability of subjectively assessed ostrich leather quality traits using threshold models. In A. Safari, B. Pattie, & B. Restall (Eds.), Proceedings of the Association for the Advancement of Animal Breeding and Genetics (Vol. 18, pp. 548-551). Association for the Advancement of Animal Breeding and Genetics (AAABG). https://hdl.handle.net/1959.11/5253

Englebrecht, A ; Cloete, S W P ; Bunter, Kim L et al. / Estimating heritability of subjectively assessed ostrich leather quality traits using threshold models. Proceedings of the Association for the Advancement of Animal Breeding and Genetics. editor / Alex Safari ; Bill Pattie ; Barrie Restall. Vol. 18 Armidale, Australia : Association for the Advancement of Animal Breeding and Genetics (AAABG), 2009. pp. 548-551

@inproceedings{e73d94bf8c2a433ea89a803719bf69db,

title = "Estimating heritability of subjectively assessed ostrich leather quality traits using threshold models",

abstract = "Several ostrich leather traits cannot be assessed objectively within the present industry structure. A subjective scoring system was devised to allow the assessment of several qualitative leather traits for the estimation of genetic parameters. Nodule size and shape, along with the presence of hair follicles and pitting damage were scored on linear scales from 1 to 9 on 1021 processed ostrich skins. The data were analysed together with live weight and skin size using threshold-linear animal models, with compression of categories where required. Heritability estimates were 0.44 for live weight, 0.33 for skin size, 0.46 for nodule size, 0.33 for nodule shape, 0.49 for hair follicles and 0.15 for pitting. The 95\% highest posterior density confidence intervals for all variance components excluded zero. The quantitative slaughter traits were favourably related to nodule shape and nodule size, while the presence of hair follicles or pitting was not significantly related to the other traits on a genetic level. Sufficient genetic variation was demonstrated to allow sustained genetic progress for objective and subjectively assessed traits.",

keywords = "Animal Breeding",

author = "A Englebrecht and Cloete, \{S W P\} and Bunter, \{Kim L\} and \{van Wyk\}, \{J B\}",

year = "2009",

language = "English",

isbn = "9780646521039",

volume = "18",

pages = "548--551",

editor = "Alex Safari and Bill Pattie and Barrie Restall",

booktitle = "Proceedings of the Association for the Advancement of Animal Breeding and Genetics",

publisher = "Association for the Advancement of Animal Breeding and Genetics (AAABG)",

note = "AAABG 2009: 18th Conference of the Association for the Advancement of Animal Breeding and Genetics ; Conference date: 27-09-2009 Through 02-10-2009",

}

Englebrecht, A, Cloete, SWP, Bunter, KL & van Wyk, JB 2009, Estimating heritability of subjectively assessed ostrich leather quality traits using threshold models. in A Safari, B Pattie & B Restall (eds), Proceedings of the Association for the Advancement of Animal Breeding and Genetics. vol. 18, Association for the Advancement of Animal Breeding and Genetics (AAABG), Armidale, Australia, pp. 548-551, AAABG 2009: 18th Conference of the Association for the Advancement of Animal Breeding and Genetics, Barossa Valley, Australia, 27/09/09. <https://hdl.handle.net/1959.11/5253>

Estimating heritability of subjectively assessed ostrich leather quality traits using threshold models. / Englebrecht, A; Cloete, S W P; Bunter, Kim L et al.
Proceedings of the Association for the Advancement of Animal Breeding and Genetics. ed. / Alex Safari; Bill Pattie; Barrie Restall. Vol. 18 Armidale, Australia: Association for the Advancement of Animal Breeding and Genetics (AAABG), 2009. p. 548-551.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › peer-review

TY - GEN

T1 - Estimating heritability of subjectively assessed ostrich leather quality traits using threshold models

AU - Englebrecht, A

AU - Cloete, S W P

AU - Bunter, Kim L

AU - van Wyk, J B

PY - 2009

Y1 - 2009

N2 - Several ostrich leather traits cannot be assessed objectively within the present industry structure. A subjective scoring system was devised to allow the assessment of several qualitative leather traits for the estimation of genetic parameters. Nodule size and shape, along with the presence of hair follicles and pitting damage were scored on linear scales from 1 to 9 on 1021 processed ostrich skins. The data were analysed together with live weight and skin size using threshold-linear animal models, with compression of categories where required. Heritability estimates were 0.44 for live weight, 0.33 for skin size, 0.46 for nodule size, 0.33 for nodule shape, 0.49 for hair follicles and 0.15 for pitting. The 95% highest posterior density confidence intervals for all variance components excluded zero. The quantitative slaughter traits were favourably related to nodule shape and nodule size, while the presence of hair follicles or pitting was not significantly related to the other traits on a genetic level. Sufficient genetic variation was demonstrated to allow sustained genetic progress for objective and subjectively assessed traits.

AB - Several ostrich leather traits cannot be assessed objectively within the present industry structure. A subjective scoring system was devised to allow the assessment of several qualitative leather traits for the estimation of genetic parameters. Nodule size and shape, along with the presence of hair follicles and pitting damage were scored on linear scales from 1 to 9 on 1021 processed ostrich skins. The data were analysed together with live weight and skin size using threshold-linear animal models, with compression of categories where required. Heritability estimates were 0.44 for live weight, 0.33 for skin size, 0.46 for nodule size, 0.33 for nodule shape, 0.49 for hair follicles and 0.15 for pitting. The 95% highest posterior density confidence intervals for all variance components excluded zero. The quantitative slaughter traits were favourably related to nodule shape and nodule size, while the presence of hair follicles or pitting was not significantly related to the other traits on a genetic level. Sufficient genetic variation was demonstrated to allow sustained genetic progress for objective and subjectively assessed traits.

KW - Animal Breeding

UR - http://www.aaabg.org/proceedings18/files/engelbrecht548.pdf

UR - http://trove.nla.gov.au/work/36420775

UR - http://aaabg.org/aaabg18/

M3 - Conference contribution

SN - 9780646521039

VL - 18

SP - 548

EP - 551

BT - Proceedings of the Association for the Advancement of Animal Breeding and Genetics

A2 - Safari, Alex

A2 - Pattie, Bill

A2 - Restall, Barrie

PB - Association for the Advancement of Animal Breeding and Genetics (AAABG)

CY - Armidale, Australia

T2 - AAABG 2009: 18th Conference of the Association for the Advancement of Animal Breeding and Genetics

Y2 - 27 September 2009 through 2 October 2009

ER -

Englebrecht A, Cloete SWP, Bunter KL, van Wyk JB. Estimating heritability of subjectively assessed ostrich leather quality traits using threshold models. In Safari A, Pattie B, Restall B, editors, Proceedings of the Association for the Advancement of Animal Breeding and Genetics. Vol. 18. Armidale, Australia: Association for the Advancement of Animal Breeding and Genetics (AAABG). 2009. p. 548-551

Estimating heritability of subjectively assessed ostrich leather quality traits using threshold models

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Conference

Keywords

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