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Genetic parameter estimation for pre-weaning growth traits in Jordan Awassi sheep
Khaleel Jawasreh1, Zuhair Bani Ismail2, Feizal Iya1
1Department of Animal Production, Faculty of Agriculture, Jordan University of Science and Technology, Jordan.
Veterinary World
|April 17, 2018
Summary
This study estimated heritability and genetic correlations for Awassi lamb growth traits. Results indicate potential for genetic improvement through selection based on estimated breeding values for traits like birth weight and weaning weight.
Area of Science:
- Animal Genetics and Breeding
- Quantitative Genetics
- Sheep Production
Background:
- Pre-weaning growth traits are crucial for sheep productivity.
- Understanding genetic parameters is essential for effective breeding programs.
- Awassi sheep are a significant breed in the Middle East.
Purpose of the Study:
- To estimate heritability, genetic, and phenotypic correlations for birth weight (BWT), weaning weight (WWT), pre-weaning daily gain (PWDG), and weaning age (WA) in Awassi lambs.
- To assess genetic trends for these growth traits.
Main Methods:
- Utilized data from 5131 Awassi lambs across two Jordanian breeding stations.
- Employed a multitrait animal model and restricted maximum likelihood (REML) methods.
- Estimated covariances between growth traits.
Main Results:
- Heritability estimates ranged from 0.19±0.04 (WWT, PWDG) to 0.30±0.04 (BWT).
- Observed positive genetic correlations between BWT and other traits, and negative correlations between WWT, PWDG, and WA.
- Genetic trends for all studied traits were approximately zero.
Conclusions:
- Selection strategies should prioritize animals with high estimated breeding values.
- Controlled breeding practices are recommended for genetic improvement in Awassi lambs.
- Further research may explore specific genetic markers for growth.
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