INRA, UR83 Recherches Avicoles, F-37380 Nouzilly, France.
INRA, UR83 Recherches Avicoles, F-37380 Nouzilly, France
Poult Sci. 2014 Aug;93(8):2078-86. doi: 10.3382/ps.2014-03881. Epub 2014 Jun 3.
Cyclically cold incubation temperatures have been suggested as a means to improve resistance of broiler chickens to ascites; however, the underlying mechanisms are not known. Nine hundred eggs obtained from 48 wk Ross broiler breeders were randomly assigned to 2 incubation treatments: control I eggs were incubated at 37.6°C throughout, whereas for cold I eggs the incubation temperature was reduced by 1°C for 6 h daily from 10 to 18 d of incubation. Thereafter, chickens were reared at standard temperatures or under cold exposure that was associated or not with a postnatal cold acclimation at d 5 posthatch. At hatch, hepatic catalase activity and malondialdehyde content were measured. Serum thyroid hormone and triglyceride concentrations, and muscle expression of several genes involved in the regulation of energy metabolism and oxidative stress were also measured at hatch and 5 and 25 d posthatch. Cold incubation induced modifications in antioxidant pathways with higher catalase activity, but lower expression of avian uncoupling protein 3 at hatch. However, long-term enhancement in the expression of avian uncoupling protein 3 was observed, probably caused by an increase in the expression of the transcription factor peroxisome proliferator activated receptor-γ coactivator-1α. These effects were not systematically associated with an increase in serum triiodothyronine concentrations that were observed only in chickens exposed to both cold incubation and later acclimation at 5 d with cold rearing. Our results suggest that these conditions of cyclically cold incubation resulted in the long-term in changes in antioxidant pathways and energy metabolism, which could enhance the health of chickens reared under cold conditions.
周期性低温孵化温度被认为是提高肉鸡腹水抗性的一种方法；然而，其潜在机制尚不清楚。从 48 周龄罗斯肉鸡种鸡获得的 900 枚鸡蛋被随机分配到 2 种孵化处理中：对照 I 组的鸡蛋在整个孵化过程中保持在 37.6°C，而低温 I 组的鸡蛋在孵化的第 10 至 18 天每天降低 1°C，持续 6 小时。此后，小鸡在标准温度下饲养或在低温暴露下饲养，低温暴露与或不与出生后第 5 天的冷驯化有关。在孵化时，测量肝脏过氧化氢酶活性和丙二醛含量。在孵化时以及孵化后 5 天和 25 天，还测量血清甲状腺激素和甘油三酯浓度，以及参与能量代谢和氧化应激调节的几种基因在肌肉中的表达。低温孵化诱导抗氧化途径发生变化，过氧化氢酶活性升高，但禽类解偶联蛋白 3 的表达降低。然而，在长期观察到禽类解偶联蛋白 3 的表达增强，这可能是由于转录因子过氧化物酶体增殖物激活受体-γ共激活因子-1α的表达增加所致。这些效应并不与血清三碘甲状腺原氨酸浓度的增加系统相关，仅在暴露于低温孵化和随后在 5 天进行冷驯化的小鸡中观察到该浓度增加。我们的研究结果表明，这些周期性低温孵化的条件导致了抗氧化途径和能量代谢的长期变化，这可能增强了在低温条件下饲养的鸡的健康状况。
