Juiputta Jiraporn, Loengbudnark Wipas, Koedkanmark Thirawat, Chankitisakul Vibuntita, Boonkum Wuttigrai
Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand.
The Research and Development Network Center of Animal Breeding and Omics, Khon Kaen University, Khon Kaen, Thailand.
PLoS One. 2025 Apr 2;20(4):e0319537. doi: 10.1371/journal.pone.0319537. eCollection 2025.
Semen characteristics are crucial indicators of reproductive success and directly influence the production efficiency of native chickens, which play a vital role in sustainable poultry production systems in Thailand. Key semen traits, including mass movement, semen pH, semen volume, sperm viability, sperm abnormalities, and sperm concentration, are routinely evaluated to assess the reproductive performance of Thai native grandparent roosters. Improved reproductive efficiency in these chickens can lead to increased fertility rates, better hatchability, and enhanced productivity, significantly benefiting smallholder farmers and the poultry industry. To enhance the accuracy and efficiency of evaluating the genetic potential of grandparent roosters, this study aimed to compare rooster age groups, estimate genetic parameters and breeding values, and develop an optimal selection index for semen traits. A total of 3,475 test-day records of six semen traits from Thai native grandparent roosters (Pradu Hang Dum), obtained from the Khon Kaen University native chicken experimental farm, were analyzed using a multi-trait animal model with average information restricted maximum likelihood (AI-REML). The heritability estimates for semen volume, mass movement, sperm concentration, sperm abnormalities, sperm viability, and semen pH across age groups were low, ranging from 0.128 to 0.161, 0.102 to 0.115, 0.101 to 0.111, 0.090 to 0.091, 0.067 to 0.083, and 0.043 to 0.057, respectively. Repeatability estimates ranged from low to moderate, between 0.119 and 0.384 for all traits and age groups. Genetic correlations among semen traits ranged from ‒0.332 to 0.580, ‒0.554 to 0.640, and ‒0.631 to 0.773 for rooster age Groups 1, 2, and 3, respectively. Based on heritability and genetic correlations, the three most important semen traits identified were semen volume, mass movement, and sperm concentration. The study revealed a strong relationship between rooster age and semen quality, with the highest selection index values observed in the youngest age group (32-52 weeks). This finding highlights the potential for genetic improvement by implementing a selective breeding program targeting the top 10% of young roosters based on the developed selection index. Such a strategy would significantly accelerate genetic progress in semen traits, improving reproductive efficiency and boosting the economic viability of native chicken production. Furthermore, these findings contribute to a deeper understanding of genetic evaluation in native chicken populations and can serve as a model for developing sustainable breeding programs for other poultry breeds under tropical conditions.
精液特征是繁殖成功的关键指标，直接影响土鸡的生产效率，而土鸡在泰国可持续家禽生产系统中发挥着至关重要的作用。常规评估关键精液性状，包括活力、精液pH值、精液量、精子活力、精子畸形率和精子浓度，以评估泰国本地祖代公鸡的繁殖性能。提高这些鸡的繁殖效率可提高受精率、孵化率并增强生产力，使小农户和家禽业显著受益。为提高评估祖代公鸡遗传潜力的准确性和效率，本研究旨在比较公鸡年龄组、估计遗传参数和育种值，并制定精液性状的最佳选择指数。使用具有平均信息约束最大似然法（AI-REML）的多性状动物模型，分析了从孔敬大学土鸡实验农场获得的泰国本地祖代公鸡（Pradu Hang Dum）六个精液性状的3475条测定日记录。各年龄组精液量、活力、精子浓度、精子畸形率、精子活力和精液pH值的遗传力估计值较低，分别为0.128至0.161、0.102至0.115、0.101至0.111、0.090至0.091、0.067至0.083和0.043至0.057。重复性估计值从低到中等，所有性状和年龄组在0.119至0.384之间。精液性状之间的遗传相关性在公鸡第1、2和3年龄组中分别为-0.332至0.580、-0.554至0.640和-0.631至0.773。基于遗传力和遗传相关性，确定的三个最重要的精液性状是精液量、活力和精子浓度。该研究揭示了公鸡年龄与精液质量之间的密切关系，在最年轻的年龄组（32 - 52周）中观察到最高的选择指数值。这一发现突出了通过实施基于所制定选择指数针对前10%年轻公鸡的选择性育种计划来实现遗传改良的潜力。这样的策略将显著加速精液性状的遗传进展，提高繁殖效率并增强土鸡生产的经济可行性。此外，这些发现有助于更深入地了解土鸡群体的遗传评估，并可作为在热带条件下为其他家禽品种制定可持续育种计划的模型。
