Zhonghua zhong liu za zhi [Chinese journal of oncology]·2025
This study compares selection indices for breeder rams, finding that clean-fleece weight offers the largest genetic gain. Increasing half-sib daughters improves selection effectiveness more than half-sisters.
Area of Science:
Animal Breeding and Genetics
Quantitative Genetics
Sheep Production
Context:
Breeder ram selection strategies are crucial for genetic improvement in sheep.
Traditional selection indices face challenges in optimizing multiple breeding objectives.
Utilizing information from relatives (half-sib sisters and daughters) can enhance selection accuracy.
Purpose:
To evaluate the effectiveness of different selection indices (aggregate, restrictive, optimal) for breeder rams.
To compare the genetic gains achieved for clean-fleece weight, number of lambs, and body weight.
To analyze the impact of selecting single traits versus aggregate breeding values.
Summary:
The general selection index was used to assess breeder ram selection strategies aiming to improve clean-fleece weight, lamb number, and body weight, with staple length as an auxiliary trait.
Aggregate, restrictive, and optimal selection indices were constructed using individual ram data and information from half-sib sisters and daughters.
Optimal selection maintained clean-fleece weight genetic gain at 0.4 kg (20% retention), while restrictive selection kept body weight genetic gain constant. Selecting for clean-fleece weight alone yielded the highest aggregate breeding value gain.
Increasing the number of half-sib daughters proved more beneficial for selection effectiveness than increasing half-sib sisters when ample relative data is available.
Impact:
Provides insights into optimizing selection strategies for economically important traits in sheep breeding.
Highlights the importance of considering different types of relative information for maximizing genetic gain.
Informs breeding programs aiming for efficient genetic improvement in sheep populations.
