Physiological effects of hypoxic conditions during the plateau period on the chicken embryo

详细信息    查看全文

• 作者：A. Haronup>aup>up> ; up>up>bup> ; Y. Dahanup>cup> ; D. Shinderup>aup> ; S. Druyanup>aup>up> ; up>up>druyan@agri.huji.ac.ilup>
• 关键词：Incubation ; Hypoxia ; Growth rate ; Metabolic rate ; Broiler ; Oxygen consumption ; Chicks ; Yolk consumption ; Hypoxic stress ; Adaptation
• 刊名：Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：203
• 期：Complete
• 页码：32-39
• 全文大小：811 K
• 卷排序：203

文摘

The chick embryo employs several adaptive responses to hypoxic challenges, affecting both metabolism and oxygen (O2) transport. The present study assessed the effects of hypoxic conditions (17% O2) during the plateau phase on embryonic metabolic rate, cardiovascular parameters, and development up to hatching. The study was divided into 2 experiments: (1) Control; 17% O2 for 6 h/d on E16–E18 (6H), and 17% O2 for 12 h/d on E16–E18 (12H), and (2) Control; 12H, and 17% O2 continuously for 72 h on E16–E18, (72H). Hypoxic embryos exhibited a significant increase in heart rate and an upward trend starting on E17 in hematocrit and hemoglobin levels. We observed a decrease in metabolism in 12H and 72H embryos during the plateau period; their oxygen consumption as well as yolk consumption were lower compared to Control and they hatched with a significantly lower body temperature, indicating lower heat production. There was no evidence of adaptation or long-term effects of exposure to 17% O2 for 6 h/d. Exposure to 72 h of hypoxic conditions led to significant physiological changes and had a detrimental influence on embryonic development and growth. In contrast, exposure to 12 h/d produced moderate hypoxic changes, which helped the embryo to cope with the stress without significant influences on its growth and development. The decrease in metabolism may represent a metabolic adaptation through a decrease in resting metabolic rate and lower heat production. Such alterations may affect post-hatch performance and energy allocation between maintenance and growth, especially under stress when there is increased oxygen demand.