Co-Authors:
Piestun, Y., Institute of Animal Science, the Volcani Center, Bet Dagan, 50250, Israel
Shinder, D., Institute of Animal Science, the Volcani Center, Bet Dagan, 50250, Israel
Ruzal, M., Institute of Animal Science, the Volcani Center, Bet Dagan, 50250, Israel
Halevy, O., Department of Animal Sciences, Faculty of Agriculture, the Hebrew University of Jerusalem, Rehovot, 76100, Israel
Yahav, S., Institute of Animal Science, the Volcani Center, Bet Dagan, 50250, Israel
Abstract:
This study aimed to elucidate the effects of thermal manipulation (TM) during the development and maturation of the thyroid and adrenal axis on broiler chicks hatchability and thermoregulation during hatch, and to evaluate the improvement of thermotolerance acquisition of TM chicks by thermally challenging them post-hatch. Fertile Cobb eggs were divided into three treatments: control, 12 and 24 H. The control eggs were incubated under standard conditions, whereas the 12 and 24 H eggs were incubated from 7 d of incubation (E7) until E16 (inclusive) at 39.5 °C and 65% RH for 12 h/d (12 H) or continuously (24 H). Hatchability, BW and quality of the hatched 24 H chicks were negatively affected, but exhibited significantly improved thermotolerance on heat stress at 3 and 10 d of age for males and females, respectively. It can be concluded that continuous TM during embryogenesis impaired broiler chick performance, but improved their ability to thermoregulate in response to thermal challenge mainly by reducing heat production. © 2008 Elsevier Ltd. All rights reserved.