The Effects of the Hot, Humid Tropical Climate and Early Age Feed Restriction on Stress and Fear Responses, and Performance in Broiler Chickens

Al-Aqil, A.;Zulkifli, I.;Sazili, A.Q.;Omar, A.R.;Rajion, M.A.

  • Received : 2009.01.07
  • Accepted : 2009.03.21
  • Published : 2009.11.01


The present study was conducted to determine the effects of two types of housing systems and early age feed restriction on stress and fear reactions, and performance in broiler chickens raised in a hot, humid tropical climate. On day 1, chicks were housed either in windowless environmentally controlled chambers (temperature was set at 32$^{\circ}C$ on day 1 and gradually reduced to 23$^{\circ}C$ by day 21) or in conventional open-sided houses (OH) with cyclic temperatures (minimum, 24$^{\circ}C$; maximum, 34$^{\circ}C$). An equal number of chicks from each housing system was subjected to either ad libitum feeding (AL) or 60% feed restriction on day 4, 5 and 6 (FR). The CH birds showed greater weight gain, higher feed consumption and better feed conversion ratios (FCR) than their OH counterparts. Feeding regimen had negligible effect on overall performance. Neither housing nor feeding regimen had a significant (p<0.05) effect on mortality rate. Although the CH birds were less stressed, as measured by plasma corticosterone concentration (CORT), than those of OH, the former showed longer TI duration suggesting higher magnitude of underlying fearfulness. A significant (p<0.05) effect of housing on heterophil/lymphocyte ratios was only noted among the AL birds where the CH birds had higher values than OH. Collectively, these results suggest that although OH birds had poorer performance and higher level of stress than CH, the former were less fearful. Although FR had negligible effect on growth performance, the regimen alleviated both stress and fear reactions in broilers.


Broiler Chickens;Feed Restriction;Hot and Humid Climate


  1. Daghir, N. J. 1995a. Nutrient requirements of poultry at high temperatures. In: Poultry production in hot climates (Ed. N. J. Daghir), CAB International, Wallingford, UK. pp. 101-124
  2. Daghir, N. J. 1995b. Broiler feeding and management in hot climates. In: Poultry production in hot climates (Ed. N. J. Daghir), CAB International, Wallingford, UK. pp. 185-218
  3. Hurwitz, S. and I. Bengal. 1982. Energy use and performance of young turkeys kept under various constant and cycling environmental temperatures. Poult. Sci. 61:1082-1086
  4. Jones, R. B. 1986. The tonic immobility reaction of the domestic fowl: a review. Wld's. Poult. Sci. J. 42:82-96
  5. Lee, H. Y. and J. V. Craig. 1991. Beak teimming effects on behaviour patterns, fearfulness, feathering and mortality among three stocks of White Leghorn pullets in cages floor pens. Poult. Sci. 70:211-221
  6. Maxwell, M. H. 1993. Avian blood leucocyte response to stress. Wld's. Poult. Sci. J. 49:34-43
  7. $SAS^{{\circledR}}$ Institute. 1991. SAS/STAT User's Guide Release 6.03: Cary, NC, SAS Institute
  8. Zulkifli, I., B. Norbaiyah and A. Siti Nor Azah. 2004. Growth performance, mortality and immune response of two commercial broiler strains subjected to early age feed restriction and heat conditioning under hot, humid tropical environment. Arch. Gefl$\ddot{U}$gelk. 68:253-258
  9. Zulkifli, I., R. T. Dass and M. T. Che Norma. 1999. Acute heat stress effects on physiology and fear-related behaviour in commercial broilers and red jungle fowl. Canad. J. Anim. Sci. 79:165-170
  10. Al-Murrani, W. K., I. K. Al-Rawi and N. M. Raof. 2002. Genetic resistance to almonella typhimurium in two lines of chickens selected as resistant and sensitive on the basis of the heterophil/lymphocyte ratio. Br. Poult. Sci. 38:159-163
  11. Liew, P. K., I. Zulkifli, M. Hair-Bejo, A. R. Omar and D. A. Israf. 2003. Effects of early age feed restriction and thermal conditioning on heat shock protein 70 expression, resistance to infectious bursal disease and growth in male broiler chickens subjected to chronic heat stress. Poult. Sci. 82:1879-1885
  12. Yahav, S. and J. P. McMurtry. 2001. Thermotolerance acquisition in broiler chickens by temperature conditioning early in life the effect of timing and ambient temperature. Poult. Sci. 80:1662-1666
  13. Zulkifli, I., E. A. Dunnington, W. B. Gross and P. B. Siegel. 1994a. Food restriction early or later in life and its effect on adaptability, disease resistance, and immunocomptence of heat-stressed dwarf and nondwarf chickens. Br. Poult. Sci. 35:203-213
  14. Abu-Dieyeh, Z. H. M. 2006. Effect of high temperature per se on growth performance of broilers. Intl. J. Poult. Sci. 5:19-21
  15. Zulkifli, I., E. A. Dunnington, W. B. Gross and P. B. Siegel. 1994b. Inhibition of adrenal steroidogenesis, food restriction and acclimation to high ambient temperatures in chickens. Br. Poult. Sci. 35:417-426
  16. van Kampen, M. 1981. Water balance of colostomised and noncolostomised hens at different ambient temperatures. Br. Poult. Sci. 22:17-23
  17. Campo, J. L. and C. Carnicer. 1994. Effects of several "stressors" on tonic immobility reaction of chickens. Arch. Gefluegelk. 58:75-78
  18. Gething, M. J. and J. Sambrook. 1992. Protein folding in the cell. Nature 355:33-45
  19. Lagadic, H., J. M. Faure, A. D. Mills and J. B. Williams. 1990. Effects of blood sampling on plasma concentrations of corticosterone and glucose in laying hens caged in groups. Br. Poult. Sci. 31:823-829
  20. Ain Baziz, H., P. A. Geraert, J. C. F. Padilha and S. Guillaumin. 1996. Chronic heat exposure enhances fat deposition and modifies muscle and fat partition in broiler carcasses. Poult. Sci. 75:505-513
  21. Benoff, F. H. and P. B. Siegel. 1976. Genetic analyses of tonic immobility in young Japanese quail (Cortunix cortunix japonica). Anim. Learn. Behav. 67:226-231
  22. Yahav, S., A. Straschnow, I. Plavnik and S. Hurwitz. 1996. Effect of diurnal cyclic versus constant temperatures on chicken growth and food intake. Br. Poult. Sci. 37:43-54
  23. Arjona, A. D. M. Denbow and W. D. Weaver. 1988. Effects of heat stress early in life on mortality of broilers exposed to high environmental temperatures prior to marketing. Poult.. Sci. 67:226-231
  24. Siegel, H. S. 1995. Stress, strains and resistance. Br. Poult. Sci. 36:3-22
  25. Zulkifli, I., M. T. Che Norma, C. H. Chong and T. C. Loh. 2000b. Heterophil/lymphocyte and tonic immobility reactions to preslaughter handling in broiler chickens treated with ascorbic acid. Poult. Sci. 79:402-406
  26. Huff, G. R., W. E. Huff, J. M. Balog, N. C. Rath, N. B. Anthony and K. E. Nestor. 2005. Stress response differences and disease susceptibility reflected by heterophil to lymphocyte ratio in turkeys selected for increased body weight. Poult. Sci. 84:709-717
  27. Zulkifli, I., M. T. Che Norma, D. A. Israf and A. R. Omar. 2000a. The effect of early age feed restriction on subsequent response to high environmental temperatures in female broiler chickens. Poult. Sci. 79:1401-1407
  28. Bayyari, G. R., W. E. Huff, N. C. Rath, J. M. Balog, L. A. Newberry, J. D. Villines, J. K. Skeeles, N. B. Anthony and K. E. Nestor. 1997. Effect of the genetic selection of turkeys for increased body weight and egg production on immune and physiological responses. Poult. Sci. 76:289-296
  29. Geraert, P. A., J. C. F. Padilha and S. Guillaumin. 1996. Metabolic and endocrine changes induced by chronic heat exposure in broiler chickens: growth performance, body composition and energy retention. Br. J. Nutrn. 75:195-204
  30. Jones, R. B. and J. B. Williams. 1992. Responses of pair-housed male and female domestic chicks to the removal of a companion. Appl. Anim. Behav. Sci. 32:375-380
  31. Gross, W. B. and H. S. Siegel. 1983. Evaluation of heterophil/lymphocyte as a measurement of stress in chickens. Avian Dis. 27:972-979
  32. Zulkifli, I. 1999. Heterophil/lymphocyte response and performance of feed and water restricted broiler chickens under tropical conditions. Asian-Aust. J. Anim. Sci. 12:951-955
  33. Harvey, S., B. J. Merry and J. G. Phillips. 1980. Influence of stress on the secretion of corticosterone in the duck (Anas platyrhynchos). J. Endocrinol. 87:161-171
  34. Zuprizal, M. Larbier, A. M. Chagneau and P. A. Geraert. 1993. Influence of ambient temperature on true digestibility of protein and amino acids of rapeseed and soybean meals in broilers. Poult. Sci. 72:289-295
  35. Zulkifli, I., A. Al-Aqil, A. R. Omar, A. Q. Sazili and M. A. Rajion. 2009. Crating and heat stress influences blood parameters and heat shock protein 70 expression in broiler chickens showing short or long tonic immobility reactions. Poult. Sci. 88:471-476

Cited by

  1. Effect of Feeding Time Restriction During the Growing Period on Growth Performance of Broiler Chickens vol.11, pp.2, 2017,
  2. Climatic Variation: Effects on Stress Levels, Feed Intake, and Bodyweight of Broilers vol.19, pp.3, 2017,
  3. Propolis supplementation attenuates the negative effects of oxidative stress induced by paraquat injection on productive performance and immune function in turkey poults vol.96, pp.12, 2017,
  4. Utilizing original XPC™ in feed to reduce stress susceptibility of broilers vol.97, pp.3, 2017,


Supported by : King Faisal University