期刊
POULTRY SCIENCE
卷 96, 期 1, 页码 234-240出版社
OXFORD UNIV PRESS
DOI: 10.3382/ps/pew298
关键词
thermal manipulation; heat stress; broiler chicks; heterophil/lymphocyte ratio; growth
资金
- Deanship of Research-Jordan University of Science & Technology project [180/2007]
The effects of thermal manipulation (TM) at 38.5. C and 40. C for 6 h at embryonic day (ED) 16, 9 h at ED 17, and 12 h at ED 18 on body weight (BW) and cloacal body temperature (T-b) during the first wk and later at post-hatch d 10, 14, 21, 28, and 42 were evaluated. Furthermore, chicks' ability to cope with a thermal challenge (TC; 41 degrees C for 6 h) at post-hatch d 14 and 42 was also evaluated. A chick's response to TC was measured by determining the cloacal body temperature; the plasma thyroid hormones (thyroxin (T-4) and triiodothyronine (T-3)); the packed cell volume (PCV); the heterophil (H), lymphocyte (L), monocyte, basophil, and eosinophil percentages; and the heterophil-to-lymphocyte ratios (H/L). Thermal manipulation did not affect the hatch-ability. However, the body weight of TM chicken was higher compared with controls at marketing age (post-hatch d 42). At post-hatch d 14 and 42, no significant changes in T-b were observed among the different treatment groups. However, during TC at d 14 and 42, the T-b of TM chicks was lower compared with the controls. During TC, a significant increase in plasma T-4 and a significant decrease in plasma T-3 of TM chicks compared with controls were reported. Furthermore, during TC, a significant increase in the PCV and heterophil, monocyte, and H/L ratios, and a reduction in the lymphocyte percentages also were observed in TM chicks compared with the controls. Results of this study showed that chicks subjected to heat manipulation during late embryogenesis respond better to heat stress later in the growth and development period.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据