The use of natural antioxidants, in particular polyphenols such as dihydroquercetin (DHQ), in animal nutrition have recently increased in popularity. This may partly be due to the risk of increased incidences of heat stress associated with raising livestock in warmer ambient temperatures, facilitated by global warming, reducing antioxidant capacity. The current research demonstrates the effect of dietary DHQ, vitamin E and standard or high ambient temperatures on growth performance, energy and nutrient metabolism, gastrointestinal tract development (GIT), jejunal villus morphometry and antioxidant status in broiler chickens. Each of the four experimental diets were fed to 16 pens of five birds, which were allocated to four rooms (four pens in each room). The temperature in two rooms was maintained at a constant 35 °C (high temperature; HT), and the temperature in the other two rooms was gradually reduced from 27 °C at 7d of age to 22 °C at 20d of age (standard temperature; ST). Rearing birds at HT reduced: feed intake, weight gain, weight of small intestine, total GIT, liver, spleen, heart, villus height, villus surface area and lowered blood glutationperoxidase (GSH-Px). Dietary DHQ increased blood GSH-Px and total antioxidant status, increased heart weight and reduced caecal size. When fed separately, DHQ and vitamin E improved hepatic vitamin E concentration. Feeding vitamin E increased spleen and liver weights. When fed together, DHQ and vitamin E reduced villus height, villus height to crypt depth ratio and villus surface area. Temperature and antioxidants did not affect energy and nutrient metabolism. There were no effects of dietary antioxidants on growth performance of broiler chickens and there were no mortalities. At present it is unclear if feeding antioxidants (in particular DHQ) at different levels, using different dietary formulations, and rearing birds under a range of environmental conditions may be effective at enhancing production performance and bird health in hot ambient climates.

中文翻译：

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将二氢槲皮素和维生素E饲喂在标准和较高环境温度下饲养的肉鸡

天然抗氧化剂，特别是多酚，例如二氢槲皮素（DHQ）在动物营养中的使用近来越来越流行。这可能部分是由于在全球变暖的促进下，由于在较温暖的环境温度下饲养牲畜而增加了热应激发生的风险，从而降低了抗氧化能力。当前的研究表明日粮DHQ，维生素E和标准或较高的环境温度对肉鸡生长性能，能量和营养代谢，胃肠道发育（GIT），空肠绒毛形态和抗氧化剂状态的影响。四种实验性饮食中的每一种都喂入16只五只鸡的围栏，并分配到四个房间（每个房间四只围栏）。两个房间的温度保持在恒定的35°C（高温；高温），其余两个房间的温度则从7d时的27°C逐渐降低到20d时的22°C（标准温度； ST）。在高温下饲养家禽减少：饲料摄入，体重增加，小肠重量，总胃肠道，肝脏，脾脏，心脏，绒毛高度，绒毛表面积和血凝过氧化物酶（GSH-Px）降低。饮食中的DHQ会增加血液GSH-Px和总抗氧化剂的状态，增加心脏的重量，并减小盲肠的大小。单独饲喂时，DHQ和维生素E可以改善肝脏维生素E的浓度。饲喂维生素E会增加脾脏和肝脏的重量。当一起喂食时，DHQ和维生素E降低了绒毛高度，绒毛高度与隐窝深度之比和绒毛表面积。温度和抗氧化剂不会影响能量和营养物质的代谢。膳食抗氧化剂对肉鸡的生长性能没有影响，也没有死亡率。目前尚不清楚，在不同的环境条件下，使用不同的饮食配方，以不同的水平饲喂抗氧化剂（尤其是DHQ）以及在各种环境条件下饲养禽类是否可以有效地提高生产性能和改善禽类健康。