Musa Aliyu Abduljalal, Mamat-Hamidi Kamalludin, Idrus Zulkifli, Chung Eric Lim Teik, Samat Noraini, Kassim Nafeesa Abu
Department of Animal Science, Universiti Putra Malaysia, Seri Kembangan 43400 Selangor, Malaysia; Department of Animal Science, Faculty of Agriculture, Federal University Dutsin-Ma, 5001 Katsina State, Nigeria.
Department of Animal Science, Universiti Putra Malaysia, Seri Kembangan 43400 Selangor, Malaysia; Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, Seri Kembangan 43400 Selangor, Malaysia.
Poult Sci. 2025 Aug 15;104(11):105698. doi: 10.1016/j.psj.2025.105698.
This study investigated the impact of heat stress (HS) on growth performance, carcass traits, telomere length (TL), and gene expression profiles in three chicken breeds with varying growth rates: slow-growing (SAGA), medium-growing (Sasso), and fast-growing (Cobb 500). Three hundred 14-day-old male chicks were exposed to either control (25°C) or HS (34°C for 6 hours/day) conditions for four weeks in a controlled environment. Weekly growth metrics, TL at two and four weeks, Heat Shock Protein 70 (HSP70) and Insulin-Like Growth Factor-1 (IGF-1) expression in muscle and liver at two and four weeks of HS exposure, and carcass/organ yields at four weeks were analyzed. Cobb 500 chickens exhibited significant growth reductions under HS, while SAGA showed resilience. Notably, SAGA chickens exhibited a significant increase in intestinal organ mass under HS, which may indicate an adaptive response to thermal stress. HS exposure significantly shortened TL across all breeds, suggesting its utility as a universal biomarker for HS in chickens. All breeds upregulated HSP70 expression, with the Cobb 500 showing the most prominent increase. Similarly, IGF-1 was expressed (upregulated), particularly in 500 broilers at both time-points, highlighting breed-specific differences in growth performance. These results demonstrate breed-specific physiological adaptations to HS. TL and stress-related gene expression are crucial indicators of heat susceptibility and adaptation. The study provides insights into developing breed-specific management and breeding strategies to enhance poultry resilience to increasing global temperatures.
本研究调查了热应激（HS）对三种生长速度不同的鸡品种，即生长缓慢型（SAGA）、生长中等型（Sasso）和生长快速型（Cobb 500）的生长性能、胴体性状、端粒长度（TL）和基因表达谱的影响。300只14日龄雄性雏鸡在可控环境中分别暴露于对照（25°C）或热应激（34°C，每天6小时）条件下四周。分析了每周的生长指标、两周和四周时的端粒长度、热应激暴露两周和四周时肌肉和肝脏中热休克蛋白70（HSP70）和胰岛素样生长因子-1（IGF-1）的表达，以及四周时的胴体/器官产量。Cobb 500鸡在热应激下生长显著降低，而SAGA表现出恢复力。值得注意的是，SAGA鸡在热应激下肠道器官质量显著增加，这可能表明对热应激的适应性反应。热应激暴露显著缩短了所有品种的端粒长度，表明其可作为鸡热应激的通用生物标志物。所有品种均上调了HSP70的表达，其中Cobb 500的上调最为显著。同样，IGF-1也有表达（上调），特别是在两个时间点的500肉鸡中，突出了生长性能的品种特异性差异。这些结果证明了各品种对热应激的生理适应性。端粒长度和应激相关基因表达是热易感性和适应性的关键指标。该研究为制定品种特异性管理和育种策略以提高家禽对全球气温升高的恢复力提供了见解。
