Data_Sheet_1_Evaluation of the effect of the indoor environment on the physiological responses of early-gestation sows in a commercial house in China.pdf

ObjectiveThe environment influences the sow's health and physiology during gestation. This study was conducted to evaluate indoor environmental parameters and physiological responses of early-gestation sows and investigate the possible methods for assessing the thermal environment in commercial houses.
MethodsA total of 20 early-gestation sows (commercial purebred Yorkshire) with an average body weight of 193.20 ± 3.62 kg were used for this study in winter, spring, summer, and autumn. The indoor environment parameters comprising dry-bulb temperature (Tdb), relative humidity (RH), and carbon dioxide (CO2) were recorded in 30-min intervals. Physiological parameters including heart rate (HR) and respiration rate (RR) of sows were also measured every 30 min. Wet-bulb temperature (Twb) was calculated using Tdb, RH and atmospheric pressure was recorded at a nearby weather station.
ResultsThe average indoor Tdb and RH were 12.98 ± 2.03°C and 80.4 ± 6.4% in winter, 18.98 ± 2.68°C and 74.4 ± 9.0% in spring, 27.49 ± 2.05°C and 90.6 ± 6.4% in summer, and 17.10 ± 2.72°C and 64.5 ± 10.9% in autumn. A higher average concentration of CO2 was observed in winter (1,493 ± 578 mg/m3) than in spring (1,299 ± 489 mg/m3), autumn (1,269 ± 229 mg/m3), and summer (702 ± 128 mg/m3). Compared with the HR and RR in the optimum environment, high RH in the house led to a significant decrease in both HR and RR (P < 0.05). In addition, a significant decline in HR was also obtained at high temperatures (P < 0.05). A temperature humidity index (THI), THI = 0.82 × Tdb + 0.18 × Twb, was determined for early-gestation sows, and the THI thresholds were 25.6 for HR. The variation in THI in summer showed that heat stress still occurred under the pad-fan cooling system.
ConclusionThis study demonstrated the critical significance of considering physiological responses of early-gestation sows in commercial houses and THI thresholds. We recommend that much more cooling measures should be taken for early-gestation sows in summer.

【研究目的】 妊娠期间，舍内环境会影响母猪的健康与生理机能。本研究旨在评估妊娠早期母猪的室内环境参数及生理响应，并探索规模化猪场舍内热环境的可行评估方法。【研究方法】 本研究于冬、春、夏、秋四季开展，共选用20头平均体重为193.20±3.62 kg的商业纯种约克夏（Yorkshire）妊娠早期母猪。以30分钟为间隔，记录室内环境参数：干球温度（dry-bulb temperature, Tdb）、相对湿度（relative humidity, RH）及二氧化碳（carbon dioxide, CO₂）浓度；同时每30分钟测定母猪的生理参数：心率（heart rate, HR）与呼吸率（respiration rate, RR）。基于干球温度与相对湿度计算湿球温度（wet-bulb temperature, Twb），并通过邻近气象站获取大气压强数据。【研究结果】 冬季室内平均干球温度与相对湿度分别为12.98±2.03℃、80.4±6.4%，春季为18.98±2.68℃、74.4±9.0%，夏季为27.49±2.05℃、90.6±6.4%，秋季为17.10±2.72℃、64.5±10.9%。冬季舍内二氧化碳平均浓度（1493±578 mg/m³）显著高于春季（1299±489 mg/m³）、秋季（1269±229 mg/m³）与夏季（702±128 mg/m³）。与最优环境下的心率、呼吸率相比，舍内高相对湿度会导致两项生理指标均显著下降（P<0.05）；此外，高温环境同样会使心率出现显著降低（P<0.05）。本研究为妊娠早期母猪构建了温湿度指数（temperature humidity index, THI）计算公式：THI=0.82×Tdb+0.18×Twb，并确定了针对心率的THI临界值为25.6。夏季温湿度指数的变化结果显示，即便采用湿帘-风机降温系统（pad-fan cooling system），仍存在热应激现象。【研究结论】 本研究证实，在规模化猪场中关注妊娠早期母猪的生理响应及温湿度指数临界值具有重要意义。我们建议夏季需为妊娠早期母猪采取更为完善的降温措施。