Advanced Search
British Poultry Science
Yahav, S., Institute of Animal Science, Agricultural Rescard Organisation, Bet Dagan, Israel, Institute of Animal Science, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Plavnik, I., Institute of Animal Science, Agricultural Rescard Organisation, Bet Dagan, Israel, Institute of Animal Science, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
The effects of early-age thermal conditioning and food restriction on performance and thermotolerance were studied in male broiler chickens, in 2 trials. 2. Chickens were exposed to 36°±1°C and 70% to 80% relative humidity (RH) for 24 h at the age of 5 d (thermal conditioning, TC), or to food restriction (FR) at the age of 7 to 14 d, or to both treatments (TC+FR), while a control group was reared under standard conditions. At the age of 42 d, chickens were thermally challenged by a heat stress of 35°±1°C and 20% to 30% RH for 6 h. 3. In both experiments, weight gain of the TC chickens between the ages of 7 and 42 d was significantly higher than those of other treatments and was associated with higher food intake. 4. Early-age TC significantly increased body temperature (Tb). Thermal challenge at the age of 42 d markedly increased Tb in all groups but that of the TC groups was the lowest. 5. Mortality during thermal challenge was significantly lower in the treated chickens, except for the FR group in trial 2. 6. Plasma triiodothyronine (T3) concentration was greatly depressed in all treatment groups during the thermal challenge. However, the lowest concentration was observed in the TC group, suggesting that these chickens exhibit the lowest rate of heat production under such conditions. 7. Thermal conditioning reduced the increase of haematocrit with age, whereas food restriction resulted in an increase in haematocrit immediately after FR. Thermal challenge resulted in a haematocrit decline in all groups, with the lowest values in the TC and TC+FR chickens. 8. It can be concluded that, because the TC treatment improved thermotolerance (possibly by reducing heat production) and performance, it has advantages over the FR and TC+FR treatments. © 1999, British Poultry Science Ltd.
Powered by ClearMash Solutions Ltd -
Volcani treasures
About
Terms of use
Effect of early-age thermal conditioning and food restriction on performance and thermotolerance of male broiler chickens
40
Yahav, S., Institute of Animal Science, Agricultural Rescard Organisation, Bet Dagan, Israel, Institute of Animal Science, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Plavnik, I., Institute of Animal Science, Agricultural Rescard Organisation, Bet Dagan, Israel, Institute of Animal Science, Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Effect of early-age thermal conditioning and food restriction on performance and thermotolerance of male broiler chickens
The effects of early-age thermal conditioning and food restriction on performance and thermotolerance were studied in male broiler chickens, in 2 trials. 2. Chickens were exposed to 36°±1°C and 70% to 80% relative humidity (RH) for 24 h at the age of 5 d (thermal conditioning, TC), or to food restriction (FR) at the age of 7 to 14 d, or to both treatments (TC+FR), while a control group was reared under standard conditions. At the age of 42 d, chickens were thermally challenged by a heat stress of 35°±1°C and 20% to 30% RH for 6 h. 3. In both experiments, weight gain of the TC chickens between the ages of 7 and 42 d was significantly higher than those of other treatments and was associated with higher food intake. 4. Early-age TC significantly increased body temperature (Tb). Thermal challenge at the age of 42 d markedly increased Tb in all groups but that of the TC groups was the lowest. 5. Mortality during thermal challenge was significantly lower in the treated chickens, except for the FR group in trial 2. 6. Plasma triiodothyronine (T3) concentration was greatly depressed in all treatment groups during the thermal challenge. However, the lowest concentration was observed in the TC group, suggesting that these chickens exhibit the lowest rate of heat production under such conditions. 7. Thermal conditioning reduced the increase of haematocrit with age, whereas food restriction resulted in an increase in haematocrit immediately after FR. Thermal challenge resulted in a haematocrit decline in all groups, with the lowest values in the TC and TC+FR chickens. 8. It can be concluded that, because the TC treatment improved thermotolerance (possibly by reducing heat production) and performance, it has advantages over the FR and TC+FR treatments. © 1999, British Poultry Science Ltd.
Scientific Publication
You may also be interested in