Genetic opportunities to improve lamb weaning rates in Merinos

Richard Apps; Daniel Brown; Alex Ball; R Banks; S Field

Genetic opportunities to improve lamb weaning rates in Merinos

Richard Apps
, Daniel Brown
, Alex Ball
, R Banks
, S Field

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

Abstract

Opportunities to improve genetic merit for number of lambs weaned (NLW) and scrotal circumference (SC) are relatively untapped by Merino breeders. Data from the Merino Genetic Services (MGS) database was analysed to determine the heritability of yearling and hogget scrotal circumference and number of lambs weaned as well as their genetic correlations. NLW was found to be lowly heritable at 0.06. Scrotal circumference at yearling and hogget ages was moderately heritable at 0.37 and 0.36 respectively. The genetic correlation between yearling SC and NLW was moderately positive at 0.35 (0.30) suggesting that yearling SC may be a useful indirect selection tool for NLW. The standard error associated with these correlations suggests that more data is needed to more accurately describe this relationship. Examination of the range in estimated breeding values (EBV) within the MGS database illustrates significant genetic variation for these traits. Among the 256,000 Merinos in this database the range in NLW EBV is 77.3%. That is, the daughters of a ram at the high end of the range are expected to wean, on average, 38.6% more lambs than the daughters a ram at the low end of the EBV range. The range in yearling scrotal circumference EBV is 6.3cm. Given the estimated genetic variation in NLW and SC and the genetic parameters derived from this data set there appear to be significant genetic opportunities for improved lamb weaning rates in Merino sheep.

Original language	English
Title of host publication	Proceedings of the Association for the Advancement of Animal Breeding and Genetics
Editors	Abigail Henderson
Place of Publication	Armidale, Australia
Publisher	Association for the Advancement of Animal Breeding and Genetics (AAABG)
Pages	249-252
Volume	15
ISBN (Print)	0958629927
Publication status	Published - 2003
Event	AAABG 2003: 15th Conference of the Association for the Advancement of Animal Breeding and Genetics - Melbourne, Australia Duration: 7 Jul 2003 → 11 Jul 2003

Conference

Conference	AAABG 2003: 15th Conference of the Association for the Advancement of Animal Breeding and Genetics
City	Melbourne, Australia
Period	7/07/03 → 11/07/03

Keywords

Animal Breeding

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https://hdl.handle.net/1959.11/4383

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@inproceedings{fe1a645bff66433595eb3237728a3f41,

title = "Genetic opportunities to improve lamb weaning rates in Merinos",

abstract = "Opportunities to improve genetic merit for number of lambs weaned (NLW) and scrotal circumference (SC) are relatively untapped by Merino breeders. Data from the Merino Genetic Services (MGS) database was analysed to determine the heritability of yearling and hogget scrotal circumference and number of lambs weaned as well as their genetic correlations. NLW was found to be lowly heritable at 0.06. Scrotal circumference at yearling and hogget ages was moderately heritable at 0.37 and 0.36 respectively. The genetic correlation between yearling SC and NLW was moderately positive at 0.35 (0.30) suggesting that yearling SC may be a useful indirect selection tool for NLW. The standard error associated with these correlations suggests that more data is needed to more accurately describe this relationship. Examination of the range in estimated breeding values (EBV) within the MGS database illustrates significant genetic variation for these traits. Among the 256,000 Merinos in this database the range in NLW EBV is 77.3\%. That is, the daughters of a ram at the high end of the range are expected to wean, on average, 38.6\% more lambs than the daughters a ram at the low end of the EBV range. The range in yearling scrotal circumference EBV is 6.3cm. Given the estimated genetic variation in NLW and SC and the genetic parameters derived from this data set there appear to be significant genetic opportunities for improved lamb weaning rates in Merino sheep.",

keywords = "Animal Breeding",

author = "Richard Apps and Daniel Brown and Alex Ball and R Banks and S Field",

year = "2003",

language = "English",

isbn = "0958629927",

volume = "15",

pages = "249--252",

editor = "Abigail Henderson",

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 2003: 15th Conference of the Association for the Advancement of Animal Breeding and Genetics ; Conference date: 07-07-2003 Through 11-07-2003",

}

Apps, R, Brown, D, Ball, A, Banks, R & Field, S 2003, Genetic opportunities to improve lamb weaning rates in Merinos. in A Henderson (ed.), Proceedings of the Association for the Advancement of Animal Breeding and Genetics. vol. 15, Association for the Advancement of Animal Breeding and Genetics (AAABG), Armidale, Australia, pp. 249-252, AAABG 2003: 15th Conference of the Association for the Advancement of Animal Breeding and Genetics, Melbourne, Australia, 7/07/03. <https://hdl.handle.net/1959.11/4383>

Genetic opportunities to improve lamb weaning rates in Merinos. / Apps, Richard; Brown, Daniel; Ball, Alex et al.
Proceedings of the Association for the Advancement of Animal Breeding and Genetics. ed. / Abigail Henderson. Vol. 15 Armidale, Australia: Association for the Advancement of Animal Breeding and Genetics (AAABG), 2003. p. 249-252.

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

TY - GEN

T1 - Genetic opportunities to improve lamb weaning rates in Merinos

AU - Apps, Richard

AU - Brown, Daniel

AU - Ball, Alex

AU - Banks, R

AU - Field, S

PY - 2003

Y1 - 2003

N2 - Opportunities to improve genetic merit for number of lambs weaned (NLW) and scrotal circumference (SC) are relatively untapped by Merino breeders. Data from the Merino Genetic Services (MGS) database was analysed to determine the heritability of yearling and hogget scrotal circumference and number of lambs weaned as well as their genetic correlations. NLW was found to be lowly heritable at 0.06. Scrotal circumference at yearling and hogget ages was moderately heritable at 0.37 and 0.36 respectively. The genetic correlation between yearling SC and NLW was moderately positive at 0.35 (0.30) suggesting that yearling SC may be a useful indirect selection tool for NLW. The standard error associated with these correlations suggests that more data is needed to more accurately describe this relationship. Examination of the range in estimated breeding values (EBV) within the MGS database illustrates significant genetic variation for these traits. Among the 256,000 Merinos in this database the range in NLW EBV is 77.3%. That is, the daughters of a ram at the high end of the range are expected to wean, on average, 38.6% more lambs than the daughters a ram at the low end of the EBV range. The range in yearling scrotal circumference EBV is 6.3cm. Given the estimated genetic variation in NLW and SC and the genetic parameters derived from this data set there appear to be significant genetic opportunities for improved lamb weaning rates in Merino sheep.

AB - Opportunities to improve genetic merit for number of lambs weaned (NLW) and scrotal circumference (SC) are relatively untapped by Merino breeders. Data from the Merino Genetic Services (MGS) database was analysed to determine the heritability of yearling and hogget scrotal circumference and number of lambs weaned as well as their genetic correlations. NLW was found to be lowly heritable at 0.06. Scrotal circumference at yearling and hogget ages was moderately heritable at 0.37 and 0.36 respectively. The genetic correlation between yearling SC and NLW was moderately positive at 0.35 (0.30) suggesting that yearling SC may be a useful indirect selection tool for NLW. The standard error associated with these correlations suggests that more data is needed to more accurately describe this relationship. Examination of the range in estimated breeding values (EBV) within the MGS database illustrates significant genetic variation for these traits. Among the 256,000 Merinos in this database the range in NLW EBV is 77.3%. That is, the daughters of a ram at the high end of the range are expected to wean, on average, 38.6% more lambs than the daughters a ram at the low end of the EBV range. The range in yearling scrotal circumference EBV is 6.3cm. Given the estimated genetic variation in NLW and SC and the genetic parameters derived from this data set there appear to be significant genetic opportunities for improved lamb weaning rates in Merino sheep.

KW - Animal Breeding

UR - http://trove.nla.gov.au/work/10355225?selectedversion=NBD25299699

UR - http://www.aaabg.org/livestocklibrary/2003/249-252.pdf

M3 - Conference contribution

SN - 0958629927

VL - 15

SP - 249

EP - 252

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

A2 - Henderson, Abigail

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

CY - Armidale, Australia

T2 - AAABG 2003: 15th Conference of the Association for the Advancement of Animal Breeding and Genetics

Y2 - 7 July 2003 through 11 July 2003

ER -

Genetic opportunities to improve lamb weaning rates in Merinos

Abstract

Conference

Keywords

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