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Heritability and Genetic Correlation of Age at First Egg and Egg Number Up to 40 Weeks of Age After Long-Term Selection in Taiwan Indigenous Chicken
by
,
Der-Yuh Lin
1, 
Chia-Te Chu
1,2,
Mu-Yao Lin
3,
Ming-Yang Tsai
4,
Shwu-Jen Tzeng
5,
Ming-Che Wu
1 and
Hsiu-Luan Chang
6,* 1
Genetics and Physiology Division, Taiwan Livestock Research Institute, Ministry of Agriculture, Tainan 71246, Taiwan
2
Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan 70154, Taiwan
3
Formosan Farmers Association for Swine Improvement, Taipei 24242, Taiwan
4
Livestock Management Division, Taiwan Livestock Research Institute, Ministry of Agriculture, Tainan 71246, Taiwan
5
Department of Medical Laboratory Science and Biotechnology, Chung Hwa University of Medical Technology, Tainan 71703, Taiwan
6
Department of Animal Science, National Pingtung University of Science and Technology, Pingtung 91201, Taiwan
*
Author to whom correspondence should be addressed.
Animals 2025, 15(11), 1534; https://doi.org/10.3390/ani15111534
Submission received: 14 April 2025
/
Revised: 12 May 2025
/
Accepted: 20 May 2025
/
Published: 23 May 2025
(This article belongs to the Special Issue Livestock and Poultry Genetics and Breeding Management)
Simple Summary
We estimated the genetic parameters of egg-laying-related traits in different generational stages of four Taiwan indigenous chicken lines. All four lines were derived from in situ conservation populations of the National Livestock Biodiversity Program and had undergone long-term selection for egg-laying traits since 1987. The results showed that the estimated genetic parameters of the investigated traits fluctuated among the generational stages, and the extent of fluctuation varied by line. The heritability and correlation estimates of the traits of the final stage of the selected generations suggest that the sustainability of breeding programs and the selection of the four traits from this study can still be improved.
Abstract
The objective of this study was to estimate the genetic parameters of the egg-laying traits of hens after long-term selection. Four lines were derived from Taiwan indigenous chickens conserved in situ by the National Livestock Biodiversity Program. A total of 9834 hens’ laying records from 18 non-overlapping generations classified as seven generational stages from 2006 to 2023 was used. The traits evaluated included body weight at 16 weeks of age, age at the first egg (Sday), body weight change between Sday and 40 weeks of age (Gain40), mean egg weight at 40 weeks of age (EW40), and egg number up to 40 weeks of age (EN40). A four-trait animal model via the REML procedure was used to estimate the variance/covariance components for each generational stage within each line. The ranges of the heritability estimates for Sday, Gain40, EW40, and EN40 were 0.09–0.61, 0.03–0.70, 0.32–0.83, and 0.00–0.65, respectively. Within the lines’ generational stages, most of the heritability estimates of Gain40 and EW40 were higher than those of Sday and EN40. Also, less fluctuation was found in the heritability estimates of Gain40 and EW40 among the generational stages within the lines. Favorable negative genetic and phenotypic correlations between Sday and EN40 were observed at the last generational stage, which could be beneficial for future breeding programs to improve egg production.
Keywords:
animal model; chicken; genetic parameter; laying trait; selection
