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Modifying the Response of Male Broiler Chickens to Heat Stress Through Early Age Feed Restriction and Thermal Conditioning

Two experiments were conducted to investigate the effects of early age feed restriction and heat conditioning on tolerance to acute and chronic heat stress in male broiler chickens. In both experiments, equal numbers of chickens were subjected to (i) 60% feed restriction on day 4, 5, and 6 (FR),...

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Main Author: Liew, Pit Kang
Format: Thesis
Language:English
English
Published: 2002
Subjects:
Broilers (Poultry) - Case studies
Online Access:http://psasir.upm.edu.my/id/eprint/10612/1/FP_2002_27.pdf
http://psasir.upm.edu.my/id/eprint/10612/
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spelling my.upm.eprints.106122024-04-26T03:27:12Z http://psasir.upm.edu.my/id/eprint/10612/ Modifying the Response of Male Broiler Chickens to Heat Stress Through Early Age Feed Restriction and Thermal Conditioning Liew, Pit Kang Two experiments were conducted to investigate the effects of early age feed restriction and heat conditioning on tolerance to acute and chronic heat stress in male broiler chickens. In both experiments, equal numbers of chickens were subjected to (i) 60% feed restriction on day 4, 5, and 6 (FR), (ii) exposure to 36±IoC and 50-60% relative humidity for 1 hour from day 1 to 21 (HT), (iii) 60% feed restriction on day 4, 5, and 6 and exposure to 36± l oC and 50-60% relative humidity for 1 hour from day 1 to 21 (FRHT). (iv) ad libitum feeding and no heat treatment (control). In experiment I, on day 35, all birds were exposed to 39± l oC for 6 hours and 50% relative humidity. Subjecting chicks to FR, HT and FRHT reduced HLR response to the heat challenge. Following heat exposure, the FR and FRHT chick had greater heat shock protein (hsp) 70 density than those of controls. The hsp 70 response of HT birds was not significantly different from the other three groups. The FRHT birds were more hyperthermic than controls during heat challenge. In experiment II, from day 36- 50, all birds were exposed to 38± l oC and 80 % relative humidity for 2 hours/day. One day following heat exposure (day 37), all birds were administrated intranasally with infectious bursal disease (IBD) vaccine virus. The dosage used was l Ox of the recommended level. Subjecting chicks to FRHT improved relative weight gain and resistance to IBD infection and reduced HLR in response to the heat treatment as compared with the control birds. Although there is evidence that FR and HT can improve heat tolerance, the FRHT combination may further enhance the ability of birds to withstand chronic heat stress. The acquired improved heat tolerance resulting from FRHT, FR, and HT could be attributed to enhanced hsp 70 response. The trend of hsp 70 response correlated well with IBD lesion scores, suggesting hsp 70 may play a role in resistance against viral infection. Based on experiment I and II, it can be concluded that the present findings confirmed earlier studies that FR is effective in alleviating the adverse effects of heat stress. Subjecting birds to FRHT can further improve tolerance to chronic but not acute heat stress. 2002-09 Thesis NonPeerReviewed text en http://psasir.upm.edu.my/id/eprint/10612/1/FP_2002_27.pdf Liew, Pit Kang (2002) Modifying the Response of Male Broiler Chickens to Heat Stress Through Early Age Feed Restriction and Thermal Conditioning. Masters thesis, Universiti Putra Malaysia. Broilers (Poultry) - Case studies English
institution Universiti Putra Malaysia
building UPM Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Putra Malaysia
content_source UPM Institutional Repository
url_provider http://psasir.upm.edu.my/
language English
English
topic Broilers (Poultry) - Case studies
spellingShingle Broilers (Poultry) - Case studies
Liew, Pit Kang
Modifying the Response of Male Broiler Chickens to Heat Stress Through Early Age Feed Restriction and Thermal Conditioning
description Two experiments were conducted to investigate the effects of early age feed restriction and heat conditioning on tolerance to acute and chronic heat stress in male broiler chickens. In both experiments, equal numbers of chickens were subjected to (i) 60% feed restriction on day 4, 5, and 6 (FR), (ii) exposure to 36±IoC and 50-60% relative humidity for 1 hour from day 1 to 21 (HT), (iii) 60% feed restriction on day 4, 5, and 6 and exposure to 36± l oC and 50-60% relative humidity for 1 hour from day 1 to 21 (FRHT). (iv) ad libitum feeding and no heat treatment (control). In experiment I, on day 35, all birds were exposed to 39± l oC for 6 hours and 50% relative humidity. Subjecting chicks to FR, HT and FRHT reduced HLR response to the heat challenge. Following heat exposure, the FR and FRHT chick had greater heat shock protein (hsp) 70 density than those of controls. The hsp 70 response of HT birds was not significantly different from the other three groups. The FRHT birds were more hyperthermic than controls during heat challenge. In experiment II, from day 36- 50, all birds were exposed to 38± l oC and 80 % relative humidity for 2 hours/day. One day following heat exposure (day 37), all birds were administrated intranasally with infectious bursal disease (IBD) vaccine virus. The dosage used was l Ox of the recommended level. Subjecting chicks to FRHT improved relative weight gain and resistance to IBD infection and reduced HLR in response to the heat treatment as compared with the control birds. Although there is evidence that FR and HT can improve heat tolerance, the FRHT combination may further enhance the ability of birds to withstand chronic heat stress. The acquired improved heat tolerance resulting from FRHT, FR, and HT could be attributed to enhanced hsp 70 response. The trend of hsp 70 response correlated well with IBD lesion scores, suggesting hsp 70 may play a role in resistance against viral infection. Based on experiment I and II, it can be concluded that the present findings confirmed earlier studies that FR is effective in alleviating the adverse effects of heat stress. Subjecting birds to FRHT can further improve tolerance to chronic but not acute heat stress.
format Thesis
author Liew, Pit Kang
author_facet Liew, Pit Kang
author_sort Liew, Pit Kang
title Modifying the Response of Male Broiler Chickens to Heat Stress Through Early Age Feed Restriction and Thermal Conditioning
title_short Modifying the Response of Male Broiler Chickens to Heat Stress Through Early Age Feed Restriction and Thermal Conditioning
title_full Modifying the Response of Male Broiler Chickens to Heat Stress Through Early Age Feed Restriction and Thermal Conditioning
title_fullStr Modifying the Response of Male Broiler Chickens to Heat Stress Through Early Age Feed Restriction and Thermal Conditioning
title_full_unstemmed Modifying the Response of Male Broiler Chickens to Heat Stress Through Early Age Feed Restriction and Thermal Conditioning
title_sort modifying the response of male broiler chickens to heat stress through early age feed restriction and thermal conditioning
publishDate 2002
url http://psasir.upm.edu.my/id/eprint/10612/1/FP_2002_27.pdf
http://psasir.upm.edu.my/id/eprint/10612/
_version_ 1797910849736671232
score 13.211869

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