Genetic parameters for liveweight, wool and worm resistance traits in multi-breed Australian meat sheep. 2. Genetic relationships between traits
D. J. Brown A B and A. A. Swan AA Animal Genetics and Breeding Unit*, University of New England, Armidale, NSW 2351, Australia.
B Corresponding author. Email: dbrown2@une.edu.au
Animal Production Science 56(9) 1449-1453 https://doi.org/10.1071/AN14788
Submitted: 1 September 2014 Accepted: 18 February 2015 Published: 21 May 2015
Abstract
Australian sheep breeders aim to simultaneously breed sheep that have high growth rate, superior carcass quality and are resistant to internal parasites. The objective of this study was to estimate genetic and phenotypic relationships between 11 traits recorded in Australian meat sheep, covering liveweight, carcass and internal parasite resistance traits. The data comprised 1 046 298 animals from 149 Poll Dorset, 17 Suffolk, 24 Texel and 118 White Suffolk flocks. Within all trait groups, the different age expressions were moderately to highly correlated. The genetic correlations between liveweight with both fat and eye muscle depth were generally negative ranging between –0.10 and –0.42. Fat and eye muscle depth were moderately correlated (0.27–0.59). Results indicate that selection for an increase in liveweight will have a negative effect on fat and eye muscle depth. The negative correlations of ultrasound scan traits and worm egg count indicates that animals with high genetic merit for fat and eye muscle depth are less prone to infection from internal parasites. The results from this study have been used to review the genetic correlations used in the LAMBPLAN routine genetic evaluations conducted by Sheep Genetics.
Additional keywords: genetic correlations, internal parasite resistance, ultrasound scan.
References
Brash LD, Fogarty NM, Gilmour AR, Luff AF (1992) Genetic parameters for liveweight and ultrasonic fat depth in Australian meat and dual-purpose sheep breeds. Australian Journal of Agricultural Research 43, 831–841.| Genetic parameters for liveweight and ultrasonic fat depth in Australian meat and dual-purpose sheep breeds.Crossref | GoogleScholarGoogle Scholar |
Brown DJ, Huisman AE, Swan AA, Graser H-U, Woolaston RR, Ball AJ, Atkins KD, Banks RB (2007) Genetic evaluation for the Australian sheep industry. Proceedings of the Association for the Advancement of Animal Breeding and Genetics 17, 187–194.
Brown DJ, Swan AA, Gill JS, Ball AJ, Banks RB (2015) Genetic parameters for liveweight, wool and worm resistance traits in multi-breed Australian meat sheep: 1. Description of traits, fixed effects, variance components and their ratios. Animal Production Science
Clarke BE, Brown DJ, Ball AJ (2003) Preliminary genetic parameters for liveweight and ultrasound scan traits in Merinos. Proceedings of the Association for the Advancement of Animal Breeding and Genetics 15, 326–330.
Eady SJ, Woolaston RR, Lewer RP, Raadsma HW, Swan AA (1998) Resistance to nematode parasites in Merino sheep: correlation with production traits. Australian Journal of Agricultural Research 49, 1201–1211.
| Resistance to nematode parasites in Merino sheep: correlation with production traits.Crossref | GoogleScholarGoogle Scholar |
Gilmour AR, Gogel BJ, Cullis BR, Welham SJ, Thompson R (2002) ‘ASReml user guide release 1.0.’ (VSN International Ltd: Hemel Hempstead, UK)
Greeff JC, Karlsson LJE (1998) The genetic relationship between faecal consistency, faecal worm egg counts and wool traits in Merino sheep. Proceedings of the 6th World Congress on Genetics Applied to Livestock Production 24, 63–66.
Greeff J, Safari E, Fogarty NM, Hopkins DL, Brien FD, Atkins KD, Mortimer SI, van der Werf JHJ (2008) Genetic parameters for carcass and meat quality traits and their relationships to liveweight and wool production in hogget Merino rams. Journal of Animal Breeding and Genetics 125, 205–215.
| Genetic parameters for carcass and meat quality traits and their relationships to liveweight and wool production in hogget Merino rams.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD1czhslejtg%3D%3D&md5=efdefb81d5df60e5cd2947925e06b36aCAS | 18479272PubMed |
Huisman AE, Brown DJ (2008) Genetic parameters for body weight, wool, and disease resistance and reproduction traits in Merino sheep: 2. Genetic relationships between body weight traits and other traits. Australian Journal of Experimental Agriculture 48, 1186–1193.
| Genetic parameters for body weight, wool, and disease resistance and reproduction traits in Merino sheep: 2. Genetic relationships between body weight traits and other traits.Crossref | GoogleScholarGoogle Scholar |
Huisman AE, Brown DJ, Ball AJ, Graser H-U (2008) Genetic parameters for weight, wool, and disease resistance and reproduction traits in Merino sheep: 1. Description of traits, model comparison, variances and their ratios. Australian Journal of Experimental Agriculture 48, 1177–1185.
| Genetic parameters for weight, wool, and disease resistance and reproduction traits in Merino sheep: 1. Description of traits, model comparison, variances and their ratios.Crossref | GoogleScholarGoogle Scholar |
Ingham VM, Ponzoni RW, Gilmour AR, Pitchford WS (2003) Genetic parameters for weight, fat and eye muscle depth in South Australian Merino sheep. Proceedings of the Association for the Advancement of Animal Breeding and Genetics 15, 322–325.
Lewer RP, Woolaston RR, Howe RR (1994) Studies on Western Australian Merino Sheep. II. Genetic and phenotypic parameter estimates for objectively measured traits on ram and ewe hoggets using different model types. Australian Journal of Agricultural Research 45, 829–840.
| Studies on Western Australian Merino Sheep. II. Genetic and phenotypic parameter estimates for objectively measured traits on ram and ewe hoggets using different model types.Crossref | GoogleScholarGoogle Scholar |
Pollot GE, Greeff JC (2004) Genetic relationships between faecal egg count and production traits in commercial Merino sheep flocks. Animal Science 79, 21–32.
Safari E, Fogarty NM, Gilmour AR (2005) A review of genetic parameter estimates for wool, growth, meat and reproduction traits in sheep. Livestock Production Science 92, 271–289.
| A review of genetic parameter estimates for wool, growth, meat and reproduction traits in sheep.Crossref | GoogleScholarGoogle Scholar |
Safari E, Fogarty NM, Gilmour AR, Atkins KD, Mortimer SI, Swan AA, Brien FD, Greeff JC, van der Werf JHJ (2007) Genetic correlations among and between wool, growth and reproduction traits in Merino sheep. Journal of Animal Breeding and Genetics 124, 65–72.
| Genetic correlations among and between wool, growth and reproduction traits in Merino sheep.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2s3nvVCrsw%3D%3D&md5=6d4366f3ee82e51766434249130414daCAS | 17488356PubMed |
Vaez TR, Nicholas FW, Raadsma HW (1996) REML estimates of variance and covariance components for production traits in Australian Merino sheep using an animal model 1. Body weight from birth to 22 months. Australian Journal of Agricultural Research 47, 1235–1249.
| REML estimates of variance and covariance components for production traits in Australian Merino sheep using an animal model 1. Body weight from birth to 22 months.Crossref | GoogleScholarGoogle Scholar |
Wuliji T, Dodds KG, Land JTJ, Andrews RN, Turner PR (2001) Selection for ultrafine Merino sheep in New Zealand: heritability, phenotypic and genetic correlations of liveweight, fleece weight and wool characteristics in yearlings. Animal Science 72, 241–250.
