Genetic parameters for bodyweight, wool, and disease resistance and reproduction traits in Merino sheep: 1. Description of traits, model comparison, variance components and their ratios

Author(s)
Huisman, A E
Brown, Daniel
Ball, A
Graser, Hans
Publication Date
2008
Abstract
Both wool and sheep meat industries are interested in sheep that have a high reproduction performance and are resistant to internal parasites, in addition to the traditional traits. There is considerable interest in breeding sheep for wool, carcass, reproductive and internal parasite resistance traits simultaneously. The objective of this study was to estimate single trait genetic parameters for 40 traits recorded in Merino sheep, covering bodyweight, carcass, wool, reproduction and internal parasite resistance traits. This also involved determining the appropriate models. The results from this study will be used to review the genetic parameters used in the routine genetic evaluations conducted by Sheep Genetics. The most appropriate models included a maternal genetic effect and covariance between direct and maternal genetic effects for most of the bodyweight traits, greasy and clean fleece weight, fibre diameter and coefficient of variation of fibre diameter. The permanent environment due to the dam was not included for any trait. There was considerable genetic variation in most traits analysed; lowest heritabilities (0.09–0.10) were found for number of lambs born and weaned per lambing opportunity, and highest heritabilities (0.62–0.77) for fibre diameter. The estimated heritabilities and genetic variances, in combination with the estimated correlations, indicate that there is potential to make genetic improvement in most traits currently recorded in Australian Merino sheep.
Citation
Australian Journal of Experimental Agriculture, 48(9), p. 1177-1185
ISSN
1446-5574
0816-1089
1836-5787
1836-0939
Link
Publisher
CSIRO Publishing
Title
Genetic parameters for bodyweight, wool, and disease resistance and reproduction traits in Merino sheep: 1. Description of traits, model comparison, variance components and their ratios
Type of document
Journal Article
Entity Type
Publication

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