The Effect of Stocking Density on Stress Related Genes and Telomeric Length in Broiler Chickens

  • Beloor, J. (Department of Animal Science & Biotechnology, Jinju National University) ;
  • Kang, H.K. (Department of Animal Science & Biotechnology, Jinju National University) ;
  • Kim, Y.J. (Department of Animal Science & Biotechnology, Jinju National University) ;
  • Subramani, V.K. (Department of Animal Science & Biotechnology, Jinju National University) ;
  • Jang, I.S. (Department of Animal Science & Biotechnology, Jinju National University) ;
  • Sohn, S.H. (Department of Animal Science & Biotechnology, Jinju National University) ;
  • Moon, Yang Soo (Department of Animal Science & Biotechnology, Jinju National University)
  • Received : 2009.07.27
  • Accepted : 2009.10.05
  • Published : 2010.04.01


To be economically profitable, the poultry industry demands an increase in stocking density, which could adversely affect chicken welfare. The current study was performed to investigate the effect of stocking density on stress-related, heat shock protein genes (HSP70 and HSP90), 3-hydroxyl-3-methyl-glutaryl coenzyme A reductase (HMGCR) gene and telomere length in broiler chickens. Seven-day-old broiler chickens were housed at High (0.0578 $m^2$/bird), Standard (0.077 $m^2$/bird) and Low (0.116 $m^2$/bird) stocking densities with 8 replicates each until 35 d of age. The growth performance, such as body weight gain and average daily feed intake, was found to be significantly (p<0.05) higher in the Low density group, but these parameters did not show any difference between the High and Standard groups. Other growth performance, such as feed conversion ratio and final feed intake, showed no difference among the treated groups. The expression levels of HSP70 and HMGCR were found to be elevated with the increase of stocking density. The expression level of these genes was significantly (p<0.05) higher in the High density stocked group compared with the other groups, whereas the expression levels were not significantly different between the Low and Standard groups. The expression levels of HSP90 did not show any significant changes among the treated groups. The telomeric length of the birds housed in High density was reduced significantly (p<0.05) when compared to that of the birds in Low density. These results clearly indicate that birds stocked at high density show physiological adaptive changes indicative of stress at gene transcriptional and telomere levels.


Supported by : The Ministry for Food, Agriculture, Forestry and Fisheries


  1. Cravener, T. L., W. B. Roush and M. M. Mashaly. 1992. Broiler production under varying population-densities. Poult. Sci. 71:427-433
  2. Estevez, I. 2007. Density allowances for broilers: where to set the limits? Poult. Sci. 86:1265-1272
  3. Feddes, J. J. R., E. J. Emmanuel and M. J. Zuidhof. 2002. Broiler performance, BW variance, feed and water intake, and carcass quality at different stocking densities. Poult. Sci. 81:774-779
  4. Heckert, R. A., I. Estevez, E. Russek-Cohen and R. Pettit-Riley. 2002. Effects of density and perch availability on the immune status of broilers. Poult. Sci. 81:451-457
  5. Hong, Y. H., Y. Nishimura, D. Hishikawa, H. Tsuzuki, H. Miyahara, C. Gotoh, K. C. Choi, D. D. Feng, C. Chen, H. G. Lee, K. Katoh, S. G. Roh and S. Sasaki. 2005. Acetate and propionate short chain fatty acids stimulate adipogenesis via GPCR43. Endocrinology 146:5092-5099
  6. Martrenchar, A., D. Huonnic, J. P. Cotte, E. Boilletot and J. P. Morisse. 2000. Influence of stocking density, artificial dusk and group size on the perching behaviour of broilers. Br. Poult. Sci. 41:125-130
  7. Proudfoot, F. G., H. W. Hulan and D. R. Ramey. 1979. Effect of 4 stocking densities on broiler carcass grade, the incidence of breast blisters, and other performance traits. Poult. Sci. 58:791-793
  8. Sohn, S. H., E. J. Cho., W. J. Son and C. Y. Lee. 2007. Diagnosis of bovine freemartinism by fluorescence in situ hybridization on interphase nuclei using a bovine Y chromosome specific DNA probe. Theriogenology 68:1003-1011
  9. Zulkifli, I. and A. Sti Nor Azah. 2004. Fear and stress reactions, and the performance of commercial broiler chickens subjected to regular pleasant and unpleasant contacts with human being. Appl. Anim. Behav. Sci. 88:77-87
  10. Tomhave, A. E. and K. C. Seeger. 1945. Floor space requirements of broilers. Delaware Agric. Exp. Sta. Bull. 255
  11. Shanawany, M. M. 1988. Broiler performance under high stocking densities. Br. Poult. Sci. 29:43-52
  12. Bolton, W., R. Thompson, R. M. Jones and W. A. Dewar. 1972. Effect of stocking density on performance of broiler chicks. Br. Poult. Sci. 13:157-162
  13. Heishman, J. O., C. O. Cunningham and T. B. Clark. 1952. Floor space requirement of broilers. Poult. Sci. 31:920
  14. Martrenchar, A., J. P. Morisse, D. Huonnic and J. P. Cotte. 1997. Influence of stocking density on some behavioural, physiological, and productivity traits of broilers. Vet. Res. 28:473-480
  15. Bilgili, S. F. and J. B. Hess. 1995. Placement density influences broiler carcass grade and meat yields. J. Appl. Poult. Res. 4:384-389
  16. Pettit-Riley, R. and I. Estevez. 2001. Effects of density on perching behavior of broiler chickens. Appl. Anim. Behav. Sci. 71:127-140
  17. Von Zglinicki, T. 2002. Oxidative stress shortens telomeres. Trends Biochem. Sci. 27:339-344
  18. Von Zglinicki, T., G. Saretzki, W. Docke and C. Lotze. 1995. Mild hyperoxia shortens telomeres and inhibits proliferation of fibroblasts: a model for senescence? Exp. Cell Res. 220:186-193
  19. Basu, N. and A. E. Todgham. 2002. Heat shock protein genes and their functional significance in fish. Gene 295(2):173-183
  20. Gornati, R., E. Papis, R. Simona, T. Genciana, S. Marco and B. Giovanni. 2004. Rearing density influences the expression of stress-related genes in sea bass (Dicentrarchus labrax, L.). Gene 341:111-118
  21. Turkyilmaz, M. K. 2006. The effect of stocking density on stress reaction in broiler chickens during summer Turk. J. Vet. Anim. Sci. (1):31-36
  22. Sanotra, G. S., L. G. Lawson and K. S. Vestergaard. 2001. Influence of stocking density on tonic immobility, lameness, and tibial dyschondroplasia in broilers. J. Appl. Anim. Welf. Sci. 4:71-87
  23. Zager, R. A. and A. Johnson. 2001. Renal cortical cholesterol accumulation is integral component of the systemic stress response. Kidney Int. 60:2299-2310
  24. Hermesz, E., A. Magdolna and J. Nemcsok. 2001. Identification of two hsp90 genes in carp. Comp. Biochem. Physiol. Part C 129: 397-407
  25. Dozier, W. A., J. P. Thaxton, S. L. Branton, G. W. Morgan, D. M. Miles, W. B. Roush, B. D. Lott and Y. Vizzier-Thaxton. 2005b. Stocking density effects on growth performance and processing yields of heavy broilers. Poult. Sci. 84:1332-1338
  26. Ekstrand, C., B. Algers and J. Svedberg. 1997. Rearing conditions and foot-pad dermatitis in Swedish broiler chickens. Prev. Vet. Med. 31:167-174
  27. Estevez, I., R. C. Newberry and L. Arias de Reyna. 1997. Broiler chickens: A tolerant social system? Etologia 5:19-29
  28. Houben, M. J., J. J. Moonen, J. van Schooten and J. Hageman. 2007. Telomere length assessment: Biomarker of chronic oxidative stress? Free Radic. Biol. Med. 44:235-246
  29. Schlesinger, J. M. 1986. Heat shock proteins. J. Cell Biol. 103:321-325

Cited by

  1. Field Study on the Impact of Indoor Air Quality on Broiler Production vol.20, pp.4, 2011,
  2. Effect of Housing Systems of Cage and Floor on the Production Performance and Stress Response in Layer vol.38, pp.4, 2011,
  3. The Effects of Dietary Supplementation of Vitamin C and E on the Growth Performance and the Stress Response in Broiler Chickens vol.40, pp.1, 2013,
  4. The Effects of Dietary Supplementation of Vitamin C or E on the Expressions of Endoplasmic Reticulum Stress, Lipid and Glucose Metabolism Associated Genes in Broiler Chickens vol.40, pp.2, 2013,
  5. Comparison of Stress Response between Korean Native Chickens and Single Comb White Leghorns subjected to a High Stocking Density vol.41, pp.2, 2014,
  6. The Effect of Stocking Density and Strain on the Performance and Physiological Adaptive Responses in Broiler Chickens vol.41, pp.3, 2014,
  7. Inheritance and Heritability of Telomere Length in Chicken vol.41, pp.3, 2014,
  8. Dynamics of telomere length in the chicken vol.70, pp.04, 2014,
  9. Response to dietary supplementation of l-glutamine and l-glutamate in broiler chickens reared at different stocking densities under hot, humid tropical conditions vol.93, pp.11, 2014,
  10. Role of the Red Ginseng in Defense against the Environmental Heat Stress in Sprague Dawley Rats vol.20, pp.11, 2015,
  11. Effect of dietary supplementation of medium-chain fatty acids on growth performance and prevalence of carcass defects in broiler chickens raised in different stocking densities vol.24, pp.1, 2015,
  12. Effects of High Stocking Density on the Expression of Metabolic Related Genes in Two Strains of Chickens vol.42, pp.1, 2015,
  13. Analysis of Stress Response of Domestic Chicken Breeds for the Development of a New Synthetic Parent Stock vol.42, pp.2, 2015,
  14. Environmental temperature and stocking density effects on acute phase proteins, heat shock protein 70, circulating corticosterone and performance in broiler chickens vol.59, pp.11, 2015,
  15. Effect of Stocking Density on the Performance and Immunity of 1- to 14-d- Old Broiler Chicks vol.18, pp.4, 2016,
  16. Comparison of Stress Response in Diallel Crossed Korean Domestic Chicken Breeds vol.43, pp.2, 2016,
  17. Effects of Stocking Density and Lipopolysaccharide on Immune Organ Weights, Blood Biochemical Profiles and the mRNA Expression of Pro-inflammatory Cytokines in Chicks vol.43, pp.3, 2016,
  18. The Relationship of the Expressions of Stress-related Markers and Their Production Performances in Korean Domestic Chicken Breed vol.43, pp.3, 2016,
  19. Seasonal variation in HSP70 expression and oxidative stress in skin of zebu (Tharparkar) and crossbred (Karan Fries) cattle under tropical climate vol.48, pp.4, 2017,
  20. Effects of fumonisin B1 and mycotoxin binders on growth performance, tibia characteristics, gut physiology, and stress indicators in broiler chickens raised in different stocking densities vol.97, pp.3, 2017,
  21. Host and Environmental Factors Affecting the Intestinal Microbiota in Chickens vol.9, pp.1664-302X, 2018,