caa a22 4500 397569068 CHVBK 20180308164836.0 cr unu---uuuuu 161202e199603 xx s 000 0 eng 10.3382/ps.0750402 doi (NATIONALLICENCE)oxford-10.3382/ps.0750402 Induction of Thermotolerance in Male Broiler Chickens by Temperature Conditioning at an Early Age [Elektronische Daten] [S. YAHAV, S. HURWITZ] Chicks were conditioned by exposure to heat stress (36 ± 1 C; 70 to 80% RH) for 24 h at the age of 5, or 5 and 7 d. During conditioning, weight gain was depressed. Due to accelerated growth during the postconditioning period, a complete compensation for lost weight gain was achieved by the group conditioned at 5 d, but only a partial compensation was obtained in the group conditioned at both 5 and 7 d. At the age of 42 d, challenge with acute heat stress (35 ± 1 C; 20 to 30% RH) resulted in a large increase in cloacal temperature of the controls and a more moderate increase in the conditioned chickens. Mortality during the thermal challenge was significantly higher in the controls than that of the previously exposed (conditioned) groups. Conditioning at an early age resulted in hemodynamic changes (significant decrease in heart weight and hematocrit) and reduced plasma triiodothyronine (T3) concentration. The results suggest that reduced T3 and hemodynamic changes may be part of the mechanism associated with improved thermotolerance by early age temperature conditioning. © 1996 Poultry Science Association, Inc. Physiology and Reproduction nationallicence heat stress nationallicence conditioning nationallicence triiodothyronine nationallicence hematocrit nationallicence compensatory growth nationallicence YAHAV S. aut HURWITZ S. aut Poultry Science Oxford University Press 75/3(1996-03), 402-406 0032-5791 75:3<402 1996 75 ps https://doi.org/10.3382/ps.0750402 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.3382/ps.0750402 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- YAHAV S. aut NATIONALLICENCE 700 1- HURWITZ S. aut NATIONALLICENCE 773 0- Poultry Science Oxford University Press 75/3(1996-03), 402-406 0032-5791 75:3<402 1996 75 ps Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford