Pathak P K, Roychoudhury R, Saharia J, Borah M C, Dutta D J, Bhuyan R, Kalita D
ICAR Research Complex for NEH Region, Sikkim Centre, Tadong, Sikkim, 737102, India.
Department of LPM, College of Veterinary Science, Assam Agricultural University, Khanapara, Guwahati, 781022, India.
Trop Anim Health Prod. 2018 Jun;50(5):1025-1032. doi: 10.1007/s11250-018-1526-6. Epub 2018 Feb 13.
The present study was formulated to find out the status of important season related thermal stress biomarkers of pure-bred (Hampshire) and crossbred (50% Hampshire × 50% local) pigs under the agro-climatic condition of Assam State, India. The experiment was also aimed to study the role of different level of energy ration (110, 100, and 90% energy of NRC feeding standard for pig) in variation of physiological and biochemical parameters in two genetic groups of pigs in different seasons. The metabolizable energy value were 3260, 2936.5, and 3585.8 kcal/kg in grower ration and 3260.2, 2936.6, and 3587 kcal/kg in finisher ration for normal energy (NE), low energy (LE) and high energy (HE), respectively. Both the genetic group of animals were housed separately under intensive system of management. Each pen was measuring 10' × 12' along with an outer enclosure. Six weaned piglets (almost similar body weight of average 10.55 kg) of each group were kept in a separate pen. However, after attainment of 35 kg body weight, the animals of a group were divided in two pens of three animals each. The present experiment indicated that average ambient temperature during summer months (27.33-29.51 °C) was above the comfort zone for pigs (22 °C). The significantly (P < 0.01) higher relative humidity (RH) (%) was recorded in outdoor environment (87.26-91.10%) and in the morning time (86.60-91.10%). The temperature humidity index (THI) during the study period was found to be indicative of thermal stress to the experimental animals during summer (79.55-82.56). Physiological parameters viz., respiration rate (RR) and rectal temperature (RT) were significantly (P < 0.01) higher in summer season (43.75-72.12 breaths/min. and 102.29-103.23 °F) and non-significantly higher values were recorded in Hampshire pigs. It was also found that the significantly (P < 0.01) lower RR as well as RT was recorded in the pigs fed with high energy (HE) ration during summer season. Serum triiodothyronine (T) and thyroxine (T) concentrations were significantly (P < 0.01) lower during summer, while both the genetic groups showed significantly (P < 0.01) higher concentration of serum cortisol during summer season. It was also observed that thyroid hormone and cortisol concentrations were maintained in groups of pig fed vegetable oil incorporated HE diet during summer. From the present study, it is found that the increasing the energy level of the ration might be helpful to minimize the effects of thermal stress during summer.
本研究旨在查明在印度阿萨姆邦农业气候条件下，纯种（汉普夏）和杂交种（50%汉普夏×50%本地猪）猪重要季节相关热应激生物标志物的状况。该实验还旨在研究不同能量水平日粮（猪营养需求委员会饲养标准能量的110%、100%和90%）对两个遗传组猪在不同季节生理和生化参数变化的作用。正常能量（NE）、低能量（LE）和高能量（HE）的生长猪日粮代谢能值分别为3260、2936.5和3585.8千卡/千克，育肥猪日粮代谢能值分别为3260.2、2936.6和3587千卡/千克。两组遗传动物均在集约化管理系统下分开饲养。每个猪栏尺寸为10英尺×12英尺，带有一个外围围栏。每组六头断奶仔猪（平均体重相近，约10.55千克）饲养在单独的猪栏中。然而，在达到35千克体重后，一组动物被分成两个猪栏，每个猪栏三头。本实验表明，夏季月份的平均环境温度（27.33 - 29.51°C）高于猪的舒适区温度（22°C）。室外环境（87.26 - 91.10%）和早晨时段（86.60 - 91.10%）的相对湿度（RH）显著更高（P < 0.01）。研究期间的温度湿度指数（THI）表明夏季实验动物处于热应激状态（79.55 - 82.56）。生理参数，即呼吸频率（RR）和直肠温度（RT）在夏季显著更高（P < 0.01）（43.75 - 72.12次/分钟和102.29 - 103.23°F），汉普夏猪的这些值略高但不显著。还发现夏季喂食高能量（HE）日粮的猪的RR和RT显著更低（P < 0.01）。夏季血清三碘甲状腺原氨酸（T₃）和甲状腺素（T₄）浓度显著更低（P < 0.01），而两个遗传组在夏季血清皮质醇浓度均显著更高（P < 0.01）。还观察到夏季喂食含植物油的高能量日粮的猪群中甲状腺激素和皮质醇浓度保持稳定。从本研究发现，提高日粮能量水平可能有助于减轻夏季热应激的影响。
