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

Author(s)
Brown, Daniel
Swan, Andrew
Gill, James
Ball, Alexander
Banks, Robert
Publication Date
2016
Abstract
Sheep breeders in Australia that focus on lamb production simultaneously breed sheep that have higher growth rate, improved carcass quality and are resistant to internal parasites. The objective of this study was to estimate genetic parameters for 11 traits recorded in Australian meat sheep, covering liveweight, carcass and internal parasite resistance traits. As the population of meat sheep in this database have become increasingly crossbred this study also investigates the genetic variation within and between breeds. The data comprised 1 046 298 animals from 149 Poll Dorset, 17 Suffolk, 24 Texel and 118 White Suffolk flocks. The results are averages of analyses of 10 datasets constructed by randomly sampling 25% of these flocks. There was considerable genetic variation in all traits analysed: the lowest heritabilities (0.12) were found for weaning weight and the highest heritabilities (0.31-0.32) for eye muscle depth. There were also significant differences between breeds for most traits, which breeders appear to be utilising through crossbreeding. Direct heterosis effects were small and only significant for the liveweight traits ranging from 2% to 3.4% of the phenotypic means. Maternal heterosis was not significant for any trait studied. The inclusion of heterosis effects in the model did not significantly influence the estimated genetic parameters. The results from this study have been used to review the genetic parameters used in the LAMBPLAN routine genetic evaluations conducted by Sheep Genetics.
Citation
Animal Production Science, 56(9), p. 1442-1448
ISSN
1836-5787
1836-0939
Link
Publisher
CSIRO Publishing
Title
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
Type of document
Journal Article
Entity Type
Publication

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