Tesakul Suchawadee, Mitsuwan Watcharapong, Morita Yukio, Kitpipit Warangkana
Akkhraratchakumari Veterinary College, Walailak University, Nakhon Si Thammarat, Thailand.
One Health Research Center, Walailak University, Nakhon Si Thammarat, Thailand.
Vet World. 2025 Apr;18(4):851-858. doi: 10.14202/vetworld.2025.851-858. Epub 2025 Apr 19.
Egg production is a critical indicator of reproductive efficiency in laying hens. High environmental temperatures and humidity expose laying hens to heat stress, adversely affecting egg production, egg quality, feed intake, blood chemistry, health, and behavior. Despite the global economic significance of egg production, research on the impact of heat stress in tropical climates, particularly in locally adapted breeds, remains limited. This study investigates the effects of heat stress on egg production in a new synthetic breed of laying hens raised under hot and humid conditions.
This study utilized secondary data from the Ligor chicken development project, covering the period from January 1 to December 31, 2023. A total of 1293 daily records of egg production from 872 laying hens, aged between 20 and 70 s, were analyzed. Egg production parameters, including hen day production (HDP) and average egg weight (AEW), were recorded daily. Environmental data, including temperature and humidity, were collected at hourly intervals using a data recorder. The heat stress index (HSI) was calculated based on temperature and relative humidity values. Statistical analyses, including regression modeling, were performed to assess the relationship between HSI and egg production.
The findings demonstrated that heat stress negatively impacted egg production. A statistically significant negative correlation was observed between HSI and both HDP and AEW (p < 0.05). For each unit increase in HSI, HDP decreased by 1.29%, and AEW declined by 0.18 g. These results indicate that heat stress adversely affects the productivity of laying hens in tropical climates.
Heat stress significantly reduces egg production and egg weight in laying hens under hot and humid conditions. The findings highlight the need for adaptive breeding strategies and improved environmental management to mitigate the adverse effects of heat stress. Future research should focus on genetic selection for heat resistance and the integration of precision farming techniques to optimize poultry production in tropical regions.
产蛋量是蛋鸡繁殖效率的关键指标。高温高湿环境使蛋鸡遭受热应激，对产蛋量、蛋品质、采食量、血液生化指标、健康状况及行为产生不利影响。尽管产蛋在全球经济中具有重要意义，但关于热带气候下热应激影响的研究，尤其是针对本地适应性品种的研究仍然有限。本研究调查了热应激对在炎热潮湿条件下饲养的新型合成蛋鸡品种产蛋量的影响。
本研究利用了Ligor鸡发展项目的二手数据，涵盖2023年1月1日至12月31日期间。分析了872只年龄在20至70周龄之间的蛋鸡的1293条每日产蛋记录。每天记录产蛋参数，包括母鸡日产蛋量（HDP）和平均蛋重（AEW）。使用数据记录器每小时收集一次包括温度和湿度在内的环境数据。根据温度和相对湿度值计算热应激指数（HSI）。进行了包括回归建模在内的统计分析，以评估HSI与产蛋量之间的关系。
研究结果表明，热应激对产蛋量有负面影响。HSI与HDP和AEW之间均观察到具有统计学意义的负相关（p < 0.05）。HSI每增加一个单位，HDP下降1.29%，AEW下降0.18克。这些结果表明，热应激对热带气候下蛋鸡的生产力有不利影响。
热应激显著降低了炎热潮湿条件下蛋鸡的产蛋量和蛋重。研究结果凸显了采用适应性育种策略和改善环境管理以减轻热应激不利影响的必要性。未来的研究应侧重于耐热性的遗传选择以及精准养殖技术的整合，以优化热带地区的家禽生产。
