Department of Animal Science, Faculty of Animal Science and Fisheries, Sari Agricultural Sciences and Natural Sciences University, Sari, Iran.
Department of Animal Science, Faculty of Animal Science and Fisheries, Sari Agricultural Sciences and Natural Sciences University, Sari, Iran.
J Therm Biol. 2020 Apr;89:102520. doi: 10.1016/j.jtherbio.2020.102520. Epub 2020 Jan 16.
The present study was conducted to investigate the effects of four dietary fat types and two environmental temperatures on the hepatic mitochondrial energetic in male broilers exposed to heat stress. The birds were kept in two separate rooms at 24 °C or 36 °C from 32 to 42 d of age with four experimental groups in each room. The birds fed on the diets supplemented containing rich sources of long-chain saturated fatty acids (beef tallow), middle-length-chain saturated FA (coconut oil), monounsaturated FA (olive oil), or polyunsaturated FA (soybean oil) for ten days. At 36 °C, the highest body weight and lowest feed conversion ratio were recorded in the birds fed on the diets supplemented with coconut oil or beef tallow. Temperature and fat type significantly affected the activities of the mitochondrial electron transport chain complexes (P < 0.01). There was a significant interaction between the temperature and fat type (P < 0.01). Generally, electron transport chain complexes I-V enzymatic activities were decreased at 36 °C. The coconut oil-fed birds showed the highest complex I activity at both temperatures. The beef tallow-fed broilers showed the lowest complex II activity at 24 °C. In birds exposed to 36 °C, complex II activity was higher for birds fed saturated coconut oil or beef tallow than those feeding the unsaturated olive oil or soybean oil-supplemented diets. At 24 °C, the highest and lowest complex III activities were recorded for the coconut oil- and beef tallow-supplemented diets, respectively. At 36 °C, the activity of complex III was coconut oil > beef tallow > olive oil > soybean oil. At 24 °C, complex IV activity was highest in coconut oil- or soybean oil-fed broilers; and at 36 °C, complex IV showed the lowest activity in soybean oil-fed birds. The highest complex IV activity was observed in coconut oil-fed chickens followed by olive oil-fed and beef tallow-fed birds, respectively. At 24 or 36 °C, the highest and lowest complex V activity was observed in coconut oil-fed and soybean oil-fed chickens, respectively. ATP concentration and mitochondrial membrane potential were in the order of coconut oil > beef tallow > olive oil > soybean oil at both temperatures. Temperature and fat type significantly affected the avANT mRNA concentration. Exposure of broilers to 36 °C generally decreased the mRNA expression of avANT, with beef tallow- or coconut oil-supplemented birds showing a lower avANT mRNA expression than those receiving olive oil- or soybean oil-supplemented diets. These findings provide further information on the use of fat sources in the diet of heat stressed-broilers.
本研究旨在探讨四种饲粮脂肪类型和两种环境温度对热应激雄性肉鸡肝线粒体能量的影响。32-42 日龄时，将鸡分别饲养在温度为 24°C 或 36°C 的两个独立房间内，每个房间有四个实验组。鸡分别用富含长链饱和脂肪酸（牛脂）、中链饱和脂肪酸（椰子油）、单不饱和脂肪酸（橄榄油）或多不饱和脂肪酸（大豆油）的饲粮饲养 10 天。在 36°C 时，饲喂椰子油或牛脂饲粮的鸡体重最高，饲料转化率最低。温度和脂肪类型显著影响线粒体电子传递链复合物的活性（P<0.01）。温度和脂肪类型之间存在显著的相互作用（P<0.01）。一般来说，在 36°C 时，电子传递链复合物 I-V 的酶活性降低。在两种温度下，椰子油组的复合物 I 活性最高。在 24°C 时，牛脂组的复合物 II 活性最低。在暴露于 36°C 的鸡中，饲喂饱和椰子油或牛脂的鸡的复合物 II 活性高于饲喂不饱和橄榄油或大豆油的鸡。在 24°C 时，椰子油和牛脂饲粮组的复合物 III 活性最高。在 36°C 时，复合物 III 的活性为椰子油>牛脂>橄榄油>大豆油。在 24°C 时，椰子油或大豆油组的鸡的复合物 IV 活性最高；而在 36°C 时，大豆油组的鸡的复合物 IV 活性最低。在 24°C 时，椰子油组的鸡的复合物 IV 活性最高，其次是橄榄油组和牛脂组的鸡。在 24 或 36°C 时，椰子油组的鸡的复合物 V 活性最高，其次是大豆油组和橄榄油组的鸡。在两种温度下，ATP 浓度和线粒体膜电位均为椰子油>牛脂>橄榄油>大豆油。温度和脂肪类型显著影响 avANT mRNA 浓度。暴露于 36°C 一般会降低 avANT 的 mRNA 表达，牛脂或椰子油组的鸡比橄榄油或大豆油组的鸡的 avANT mRNA 表达更低。这些发现为热应激肉鸡日粮中脂肪来源的应用提供了更多信息。
