Effect of Heat Stress on Pregnancy Outcomes in Sprague Dawley Rats


  • Nur Akmar Nadhirah Mohd Nor
  • Mohd Nizam Haron
  • . .






Heat stress, Sprague Dawley rats, pregnancy, livestock, reproduction.


Heat stressed animal may cause problem to the farmers as it will drop the production performance and reproductive efficiency such as animal’s fertility and calving interval. In Malaysia, farmers tend to establish an open housing system or let their livestock to roam for grazing. Slightly increase in degree of hyperthermia from the environment factor could induce heat stress in animals. Hence, the aim of this study is to observe the effect of heat stress on pregnancy outcome in pregnant Sprague Dawley rats. Upon determination of oestrous, the female rats were mated. Once pregnancy was confirmed, the rats were divided into two groups. The treatment groups were exposed to the heat treatment at 41°C. While in control group, the rats were maintained at 24 °C. The treatment was given until delivery. Once delivered, the rats were euthanized. The reproductive organs were dissected and weighted. Pregnancy outcomes were observed and were seen to be affected. There was reduction in the reproductive organs weight which were the uterus and ovary, lower number of pup, alteration of offspring sex and also higher percentage of resorption. Although there was no significant finding between the two groups, but there was a pattern in the parameter observed that may indicate the effect of heat stress in pregnant rats. Therefore, heat stress may give negative effect to the pregnancy outcomes and reproductive system in rats.




[1] Lee, D.H.R. (1965) Climatic stress indices for domestic ani-mals. International. Journal Biometeorology 9-29.

[2] Giblot, D.H.A., Globa, L., Pustovyy, O., Reeves, S., Robinson, L., Vodyanoy, V. & Sorokulova, I. (2016) Mitigation of heat stress-related complications by a yeast fermentate product. Journal of Thermal Biology 60, 26–32.

[3] Parkinson, T., de Dear, R. & Candido, C. (2016) Thermal pleas-ure in built environments: alliesthesia in different thermoregu-latory zones. Building Research and Information 44, 20-33.

[4] Phillips, C. (2016) The welfare risks and impacts of heat stress on sheep shipped from Australia to the Middle East. The Veterinary Journal 218, 78-85.

[5] Quinn, C.M., Carrie M., Duran, R.M., Audet, G.N., Charkoudi-an, N. & Leon, L.R., (2014) Cardiovascular and thermoregula-tory biomarkers of heat stroke severity in a 668 conscious rat model. Journal of Applied Physiology 117, 971-978.

[6] Hansen, P.J. (2017) Heat Stress and Climate Change, Editor(s): Murray, M.Y. In Comprehensive Biotechnology (Second Edi-tion), (p. 477-485). Academic Press.

[7] De Rensis, F., Garcia-Ispierto, I. & López-Gatius F. (2015) Seasonal Heat Stress: Clinical Implications and Hormone Treat-ments for the Fertility of Dairy Cows. Theriogenology 84(5), 659-666.

[8] Silanikove, N. (1992) Effects of water scarcity and hot envi-ronment on appetite and digestion in ruminants: a review. Livestock Production Science 30, 175–194.

[9] Roman-Ponce, H., Thatcher, W.W., Bufï¬ngton, D.E., Wilcox, C.J. & Van Horn, H.H. (1977) Physiological and production responses of dairy cattle to shade structure in a subtropical en-vironment. Journal Dairy Science 60, 424–430.

[10] Collier, R. J., Eley, R. M., Sharma, A. K., Pereira, R. M. & Bufï¬ngton, D. E. (1981) Shade management in subtropical environment for milk yield and composition in Holstein and Jersey cows. Journal of Dairy Science 64, 844–849.

[11] Roberts, G. (1984) Plotting a better future for lambs: a practi-cal guide to providing shade [Heat stress reduction, sheep pro-duction, Tamarix articulata, Queensland]. Queensland Agriculture Journal 110, 25–26.

[12] Legates, J.E., Farthing, B.R., Casady, R.B. & Barrada, M.S. (1991) Body temperature and respiratory rate of lactating dairy cattle under ï¬eld and chamber conditions. Journal of Dairy Science 74, 2491–2500.

[13] Stott, G.H., Wiersma, F. & Woods, J.M. (1972) Reproductive health program for cattle subjected to environmental tempera-tures. Journal America Veterinary Medicine Association 16, 1339–1344.

[14] Stephenson, R.G.A., Suter, G.R. & Le-Feuvre, A.S., (1984) Re-duction of the effects of heat stress on lamb birth weight and survival by provision of shade. In: Lindsay, D.R. & Pearce, D.T. (Eds.), Reproduction in Sheep, pp 223–225 Cambridge: University Press.

[15] Haron M.N,. Wan F,. Siti A.S. & Mahaneem M. (2014) Tualang honey ameliorates restraint stress-induced impaired preg-nancy outcomes in rats. European Journal of Integrative Medicine 6(6), 657-663

[16] Yin, F., Chen, Z., Li, Z. Wen & Tang, J. (2011) Influence of acute heat stress on the development of GABAergic neurons in HPA-axies of mouse embryos. Journal of Thermal Biology 36(8), 486–491.

[17] Roth, Z., Meidan, R., Braw-Tal R. & Wolfenson, D. (2000) Immediate and delayed effects of heat stress on follicular de-velopment and its association with plasma FSH and inhibin concentration in cows. Journal of Reproduction Fertility 120, 83–90.

[18] Myers. M., Britt, K. L., Wreford, N. G., Ebling, F. J & Kerr, J. B. (2004) Methods for quantifying follicular 96 Effect of stress hormone antagonists numbers within the mouse ovary. Reproduction 127, 569–580.

[19] Donoghue, D.J., Krueger, B.F., Hargis, B.M., Miller, A.M. & El Halawani, A.E. (1989) Thermal stress reduces serum luteiniz-ing hormone and bioassayable hypothalamic content of lutein-izing hormone-releasing hormone in hens. Biology Reproduction 41, 419–424.

[20] Ozawa, M., Tabayashi, D., Latief, T.A., Shimizu, T., Oshima, I. & Kanai, Y. (2005) Alterations in follicular dynamics and ste-roidiogenic abilities induced by heat stress during follicular recruitment in goats. Reproduction 129, 621- 630.

[21] Macfarlane, M.S., Breen, K.K., Sakurai, H., Adams, B.M. & Adams, T.E. (2000) Effect of duration of infusion of stress-like concentrations of cortisol on follicular development and the preovulatory surge of LH in sheep. Animal Reproduction Science 63, 167–175.

[22] Shimizu, T., Ohshima, I., Ozaea, M., Takahashi, S., Tajima, A., Shiota, M., Miyazaki, H. & Kanai, Y. (2005) Heat stress dimin-ishes gonadotropin receptor expression and enhances suscepti-bility to apoptosis of rat granulosa cells. Reproduction 129, 463-472.

[23] Hsueh, A.J.W., Peck, E.J. & Clark, J.H. (1976) Control of Uter-ine Estrogen Receptor Levels by Progesterone. Endocrinology 98(2), 438–444.

[24] Weitlauf, H. M. (1988) The Physiology of Reproduction, eds. Knobil, E. & Neill, J. (Raven, New York), pp 231–262.

[25] Ealy, A.D., Drost, M. & Hansen, P.J. (1993) Developmental changes in embryonic resistance to adverse effects of maternal heat stress in cows. Journal Dairy Science 76, 2899–2905.

[26] Spencer, T.H., Johnson, G.A., Bazer, F.W., Burghardt, R.C. & Palmarini, M. (2007) Pregnancy recognition and conceptus implantation in domestic ruminants: roles of progesterone, interferons and endogenous retroviruses. Reproduction Fertility Development 19, 65-78.

[27] Thatcher, W.W., Meyer, M. D. & Daret-Desoroyers, G. (1995) Maternal recognition of pregnancy. Journal Reproduction Fertility 49, 15-28.

[28] Wathes, D.C. & Lamming, G.E. (1995) The oxytocine receptor, luteolysis and the maintenance of pregnancy. Journal of Reproduction Fertility 49, 53-67.

[29] Biggers, B.G., Geisert, R.D., Wetteman, R.P. & Buchanan, D.S. (1987) Effect of heat stress on early embryonic development in the beef cow. Journal of Animal Science 64, 1512-1518.

[30] Garbayo, J.M., Serrano, B. & López-Gatius F. (2008) Identifi-cation of novel pregnancy-associated glycoproteins (PAG) ex-pressed by the peri-implantation conceptus of domestic rumi-nants. Animal Reproduction Science 103, 120-134.

[31] Arechiga, C.F. & Hansen, P.J. (1998) Response of preimplan-tation murine embryos to heat shock as modiï¬ed by develop-mental stage and glutathione status. In Vitro Cell Deviation Biology Animal 34, 655–9. 92.

[32] Ealy, A.D., Howell, J.L., Monterroso, V.H., Arechiga, C.F. & Hansen, P.J. (1995) Developmental changes in sensitivity of bovine embryos to heat shock and use of antioxidants as thermoprotectants. Journal Animal Science 73, 1401–1407.

[33] Sakatani, M., Kobayashi, S. & Takahashi, M. (2004) Effects of heat shock on in vitro development and intracellular oxidative state of bovine pre-implantation embryos. Molecular Reproductive Deviation (67), 77–82.

[34] Ozawa, M., Hirabayashi, M. & Kanai, Y. (2002) Developmental competence and oxidative state of mouse zygotes heat-stressed maternally or in vitro. Reproduction 124, 683–689.

[35] Ozawa, M., Matsuzuka, T., Hirabayashi, M. & Kanai, Y. (2004) Redox status of the oviduct and CDC2 activity in 2-cell stage embryos in heat-stressed mice. Biological Reproduction 71,291–296.

[36] Edwards, M J. (1966) Prenatal loss of foetuses and abortion in guinea pigs. Nature 210, 223- 224.

[37] Patin, V., Lordi, B., Vincent, A., Thoumas, J.L., Vaudry, H. & Caston, J. (2002) Effect of heat stress on maternal behaviour in the rat. Brain research. Developmental brain research 139(1), 1-8.

[38] Omtvedt, I.T., Nelson, R.E., Edwards, R.L., Stephens, D.F. & Turman, E.J. (1971) Influence of heat stress during early, mid and late pregnancy of gilts. Journal Animal Science 32, 312-317.

[39] Wettermann, R.P. & Bazer, F.W. (1985) Influence of environ-mental temperature on prolificacy of pigs. Journal of Reproduction Fertility 33, 199-208.

[40] Hearnshaw H. & Wodzicka-Tomaszewska M. (1973) Effect of high ambient temperature in early and late lactation on litter growth and survival in rats. Australia Journal Biology Science 26, 1171–1178.

[41] Speakman, J. R. (2008) The physiological costs of reproduction in small mammals. Philosophical transactions of the Royal Society of London. Series B, Biological sciences 363, 375–98.

[42] Brummelte, S. & Gaela, L. A. (2010) Chronic corticosterone during pregnancy and postpartum affects maternal care, cell proliferation and depressive-like behaviour in the dam. Hormones and Behaviour 58(5), 769-779.

[43] Mulder, E.J., Robles de Medina P.G., Huizink, A.C., Van Den Bergh, B.R., Buitrlaar, J.K. & Visser, G.H. (2002) Prenatal maternal stress : effects on pregnancy and the (unborn) child. Early Human Development 70(1-2), 3-14.

[44] Navara, K.J. (2010) Programming of off spring sex ratios by maternal stress in humans:assessment of physiological mecha-nisms using a comparative approach. Journal of Computer Physiological 180, 785–796.

[45] Mousseau, T.A., & Fox, C.W. (1998) Theadaptive significance of maternal effects. Trends Ecology 13, 403–407.

[46] Weinstock, M. (2005). The potential influence of maternal stress hormones on development and mental health of the off-spring. Brain Behaviour, 19,296–308.

[47] Hauser, J. (2008) Effects of prenatal dexamethasone treat-ment on physical growth, pituitary-adrenal hormones, and per-formance of motor, motivational ,and cognitive tasks in juvenile and adolescent common marmoset tmonkeys. Endocrinology 149, 6343–6355.

[48] Bock, J., Murmu, M. S., Biala, Y., Weinstock, M. & Braun, K. (2011) Prenatal stress and neonatal handling induce sex-specific changes in dendritic complexity and dendritic spine density in hippocampal subregions of prepubertal rats. Neuroscience 193, 34–43.

[49] Lane, E.A. & Hyde, T.S. (1973) Effect of maternal stress on fertility and sex ratio: a pilot study with rats. Journal of Abnormal Psychology 82, 78–80.

[50] Perez-Crespo M., Pintado, B. & Gutierrez-Adan A. (2008) Scrotal heat stress effects on sperm viability, sperm DNA integrity, and the offspring sex ratio in mice. Molecular Reproductive Deviation 75, 40–47.

[51] Kraemer, S. (2000) The fragile male. British Medical Journal 321, 1609–1612.

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How to Cite

Akmar Nadhirah Mohd Nor, N., Nizam Haron, M., & ., . (2018). Effect of Heat Stress on Pregnancy Outcomes in Sprague Dawley Rats. International Journal of Engineering & Technology, 7(4.43), 6–9. https://doi.org/10.14419/ijet.v7i4.43.25809
Received 2019-01-13
Accepted 2019-01-13
Published 2018-12-29