Chomchuen Kitsadee, Tuntiyasawasdikul Veeraya, Chankitisakul Vibuntita, Boonkum Wuttigrai
Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002, Thailand.
Network Center for Animal Breeding and Omics Research, Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002, Thailand.
Animals (Basel). 2022 Jan 29;12(3):335. doi: 10.3390/ani12030335.
To improve the genetics of both growth and egg production, which are limitations in purebred native chickens, new genetic lines can be developed using an appropriate genetic approach. The data used in this study included 2713 body weight (BW0, BW4, BW6, BW8, and BW10), breast circumference (BrC6), chicken age at first egg (AFE), and egg production (240EP, 270EP, 300EP, and 365EP) records covering the period 2015 to 2020. A multi-trait animal model with the average information-restricted maximum likelihood (AI-REML) and a selection index was used to estimate the variance components, genetic parameters, and breeding values. The results showed that males had significantly higher weights than females ( < 0.05) from 4 to 10 weeks of age and that this difference increased over the generations. The differences between BW0 and BrC6 by sex and generation were not significant ( > 0.05). The estimated heritability of body weight ranged from 0.642 (BW0) to 0.280 (BW10); meanwhile, the estimated heritability of BrC6 was moderate (0.284). For egg production traits, the estimated heritability of 240EP, 270EP, 300EP, and 365EP was 0.427, 0.403, 0.404, and 0.426, respectively, while the estimated heritability of AFE was 0.269. The genetic and phenotypic correlations among the growth traits (BW0 to BW10) were low to highly positive. The genetic and phenotypic correlations between growth (BW0 to BW10) and BrC6 traits were positive, and the genetic correlations between BW6 (0.80), BW8 (0.84), BW10 (0.93), and BrC6 were strongly positive. Genetic correlations among the egg production traits (240EP, 270EP, 300EP, and 365EP) were low to highly positive and ranged from 0.04 to 0.86. The genetic correlations between AFE and all egg production traits were low to moderately negative and ranged from -0.14 to -0.29. The positive genetic correlations between body weight (BW6, BW8, and BW10) and egg production traits were found only in 240EP. The average genetic progress of body weight traits ranged from -0.38 to 30.12 g per generation for BW0 to BW10 ( < 0.05); the genetic progress was 0.28 cm per generation for BrC6 ( > 0.05). The average genetic progress of cumulative egg production traits ranged from 4.25 to 12.42 eggs per generation for 240EP to 365EP ( < 0.05), while the average genetic progress of AFE was -7.12 days per generation ( < 0.05). In conclusion, our study suggests that the body weight at six weeks of age (BW6), breast circumference at six weeks of age (BrC6), cumulative egg production at 240 days of age (240EP), and age at first egg (AFE) are the traits that should be used as selection criteria, as they have a positive effect on the development of growth and egg production.
为改善纯种本地鸡生长和产蛋性能方面存在的遗传局限，可采用适当的遗传方法培育新的品系。本研究使用的数据包括2015年至2020年期间2713条体重（BW0、BW4、BW6、BW8和BW10）、胸围（BrC6）、开产日龄（AFE）和产蛋量（240EP、270EP、300EP和365EP）记录。采用包含平均信息约束最大似然法（AI-REML）的多性状动物模型和选择指数来估计方差组分、遗传参数和育种值。结果表明，4至10周龄雄性体重显著高于雌性（P<0.05），且这种差异随世代增加。BW0和BrC6在性别和世代间差异不显著（P>0.05）。体重的估计遗传力范围为0.642（BW0）至0.280（BW10）；同时，BrC6的估计遗传力为中等水平（0.284）。对于产蛋性状，240EP、270EP、300EP和365EP的估计遗传力分别为0.427、0.403、0.404和0.426，而AFE的估计遗传力为0.269。生长性状（BW0至BW10）间的遗传和表型相关性为低到高度正相关。生长（BW0至BW10）与BrC6性状间的遗传和表型相关性为正，BW6（0.80）、BW8（0.84）、BW10（0.93）与BrC6间的遗传相关性为强正相关。产蛋性状（240EP、270EP、300EP和365EP）间的遗传相关性为低到高度正相关，范围从0.04至0.86。AFE与所有产蛋性状间的遗传相关性为低到中度负相关，范围从-0.14至-0.29。体重（BW6、BW8和BW10）与产蛋性状间的正遗传相关性仅在240EP中发现。BW0至BW10体重性状的平均遗传进展为每代-0.38至30.12克（P<0.05）；BrC6的遗传进展为每代0.28厘米（P>0.05）。240EP至365EP累计产蛋性状的平均遗传进展为每代4.25至12.42枚蛋（P<0.05），而AFE的平均遗传进展为每代-7.12天（P<0.05）。总之，我们的研究表明，六周龄体重（BW6）、六周龄胸围（BrC6）、240日龄累计产蛋量（240EP）和开产日龄（AFE）应作为选择标准，因为它们对生长和产蛋性能的发展具有积极影响。
