The effects and mechanisms of dietary selenium-enriched yeast (SeY, at Se 0, 0.25, and 0.50 mg/kg) on breast meat quality and oxidative stability of heat-stressed laying hens were studied. Two hundred and forty healthy Jingbai cross-bred hens at late laying period were randomly assigned to 4 experimental groups: one control group reared in a controlled thermal environment, and three treatment groups reared with heat stress (HS). The birds assigned to the controlled thermal environment were fed the basal diet, and the birds in the HS groups were fed the basal diet supplemented with 0, 0.25, or 0.50 mg Se (as SeY)/kg diet for 28 days. Chronic HS decreased pH_45min, increased lightness and drip loss, and impaired postmortem oxidative stability of breast muscle. The inclusion of SeY effectively reduced these stress-induced negative impacts, particularly on paleness, drip loss, and pH_45min decline. The SeY significantly enhanced the cellular antioxidant defense system, suppressed the reactive oxygen species (ROS) overproduction, and mitigated the mitochondrial damage and apoptosis of stressed muscle. In conclusion, dietary modification with SeY reduced quality loss and oxidative instability of meat from heat-stressed hens by maintaining a balanced mitochondrial redox status and inhibiting ROS induced myocyte apoptosis.

研究了日粮中富硒酵母（SeY，分别为Se 0、0.25和0.50 mg / kg）对热应激蛋鸡胸肉质量和氧化稳定性的影响和机理。将240只健康的京白杂交母鸡在产蛋后期随机分为4个实验组：一个对照组在热环境控制下饲养，三个处理组在热应激条件下饲养。分配给受控热环境的家禽饲喂基础饲料，HS组的家禽饲喂基础饲料，每公斤饲料添加0、0.25或0.50 mg Se（作为SeY），饲喂28天。慢性HS降低pH值_45min，增加的亮度和滴水损失，以及乳房肌肉的验尸后氧化稳定性受损。包含SeY可以有效减少这些压力引起的负面影响，特别是对肤色，滴落损失和pH值下降₄₅分钟的负面影响。SeY显着增强了细胞的抗氧化防御系统，抑制了活性氧（ROS）的过度产生，并减轻了应激肌肉的线粒体损伤和凋亡。总之，通过保持平衡的线粒体氧化还原状态和抑制ROS诱导的心肌细胞凋亡，采用SeY进行饮食改良可以降低热应激母鸡的肉质损失和氧化不稳定性。