Effect of different levels of tryptophane on performance, carcass characteristics and blood parameters of broiler chickens under heat stress condition


Department of Animal Science, Faculty of Agriculture Urmia University, Urmia, Iran


BACKGROUND: Heat stress reduces the poultry performance through physiologic changes. OBJECTIVES: This experiment was conducted to evaluate the effects of different levels of tryptophane on performance, carcass characteristics and some blood parameters of broiler chickens under heat stress condition. METHODS: Two hundred and fifty one-day-old broiler chicks (Ross 308) were used in a completely randomized design with four treatments and five replicates (pen), 10 birds in each replicate. The chickens of experimental treatments were fed basal diet (control group) and the diets plus the different levels of 100, 120 and 130 and 140% of the Ross strain tryptophane requirements. The experimental diets were used during the finisher period (day 25 to 42 of age) and under heat stress (32±1 ºC as cyclic from 9.00 AM to 5.00 PM). RESULTS: The results showed that the weight gain was  increased linearly by increasing the tryptophane level to 110% of Ross requirements but increasing the tryptophane level to 120, 130 and 140% caused the deteriorated weight gain (p<0.05). The feed conversion ratio was linearly decreased during the finisher and whole the period by supplementation of tryptophane to 110 and 120% but the higher tryptophane levels (130 and 140%) increased the feed conversion ratio during these two periods (p<0.05). Increasing the tryptophane level to 130% of Ross requirements caused a linear increase in the amount of lactate dehydrogenase, alanine amino transferase and alkaline phosphatase (p<0.05). Dietary supplementation of tryptophane had no effect on the blood urea, protein, creatinine, albumin, glucose and cholesterol at day 42 of age but triglyceride (p>0.05). Increasing the tryptophane level to 140% caused the lower blood triglyceride content (p<0.05). CONLUSIONS: Totally, the results of recent experiment show that consumption of 110 and 120% tryptophane of Ross requirements is the best level for performance improvements in broiler chickens under heat stress.


Aebi, H. (1984) Catalase in vitro. Methods Enzymol. 105: 121-126.
Al-Azraqi, A.A. (2008) Pattern of leptin secretion and oxidative markers in heat-stressed pigeons. Int J Poult Sci. 7: 1174-1176.
Altan, O., Pabuccuoglu, A., Altan, A., Konyalioglu, S., Bayraktar, H. (2003) Effect of heat stress on oxidative stress, lipid peroxidation and some stress parameters in broiler. J Br Poult. Sci. 44: 545-550.
Borges, S.A., Fischer Da Silva A.V., Majorka A., Hooge D.M., Cummings, K.R. (2004)  Physiological responses of broiler chickens to heat stress and dietary electrolyte balance (sodium plus potassium minus chloride, miliequivalents per kilogram). Poult Sci. 83: 1551-1558.
Cooper, M.A., Washburn, K.W.(1998) The relationships of body temperature to weight gain, feed consumption, and feed utilization inbroilers under heat stress. Poult Sci. 77: 237-242.
Daneshyar, M., Kermanshahi, H., Golian, A. (2012) The effects of turmeric supplementation on antioxidant status, blood gas indices and mortality in broiler chickens with T3-induced ascites. Br Poult Sci. 53: 379-385.
Donkoh, A. (1989) Ambient temperature: a factor affecting performance and physiological response of broiler chickens. Int J Biometeorol. 33: 259-265.
Duarte, K.F., Junqueira, O.M., Filard, R.S., Siqueira, J.C., Puzotti, M.M., Garcia, E.A., Molina, A.B., Laurentiz, A.C. (2013) Digestible tryptophan requirements for broilers from 22 to 42 days old. R. Bras Zootec. 42: 728-733.
Emadi, M., Kaveh, K., Jahanshiri, F., Hair-Bejo, M., Ideris, A., Alimon, A.R. (2010) Dietary Tryptophan Effects on Growth Performance and Blood Parameters in Broiler Chicks. J. Anim Vet. Adv. 9: 700-704.
Esteva-Garcia, E., Mack, S. (2000) The effect of DL-methionine and betaine on growth performanceand carcass characteristics in broilers. Anim Feed Sci Technol. 87: 151-159.
Fathi, M., Tanha, T. (2012) Antioxidant activity status and heart failure in broilers with pulmonary hypertension syndrome (PHS). Exp Anim Biol. 1: 69-80.
Iwagami, Y. (1996) Changes in the ultrastructure of human cells related to certain biological responses under hyperthermic culture conditions. Hum Cell. 9: 353-366.
Kucuk, O., Shahin, N.,  Sahin, K. (2003) Supplemental Zinc and vitamin A can alleviate negative effects of heat stress in broiler chickens. Biol Trace Elem Res. 94: 225-235.
Moneva, P., Popova-Ralcheva, S., Gudev, D., Sredkova, V., Yanchev, I. (2008) Study on the metabolic implication of supplemental tryptophan in exposed to stress chickens. Bulg J Agric Sci. 14: 424-431.
Mujahid, A., Yoshiki, Y., Akiba, Y., Toyomizu M. (2005) Superoxide radical production in chicken skeletal muscle induced by acute heat stress. Poult Sci. 84: 307-314.
Nielsen, J.A., Chapin, D.S., Johnson, J.L., Torgersen, L.K. (1992) Sertraline, a serotonin-uptake inhibitor, reduces food intake and body weight in lean and genetically obese mice. Am J Clin Nutr. 55: 185-189
Oliveira, W. P. D., Oliveira, R. F. M. D., Donzele, J. L., Oliveira Neto, R. D., Gomes, P. C., Assis Maia, A. P. D., Campos, P. H. R. F., Gasparino, E. (2013) Dietary crude protein reduction on growth and carcass performance of 22 to 42-day-old broilers reared under different temperatures. R. Bras Zootec. 42: 599-604.
Puvadolpirod, S., Thaxton, J.P. (2000) Model of physiological stress in chickens I. Response parameters. J Poult Sci. 79: 363-369.
Ramnath, V., Rekha, P.S., Sujatha, K.S. (2008)Amelioration of Heat Stress Induced Disturbances of Antioxidant Defense System in Chicken by Brahma Rasayana. Evidence Based Complement Altern Med. 5: 77-84.
Rosa, A.P., Pesti, G.M., Edwards, H.M.,  Bakalli, R. (2001) Tryptophan requirements of different broiler genotypes. Poult Sci. 80: 1718-1722.
Tabiri, H.Y., Sato, K., Takahashi, K., Toyomizu, M., Akiba, Y. (2002) Effect of heat stress and dietary tryptophan on performance and plasma amino acids concentrations of broiler chickens. Asian-Aust. J Anim Sci. 15: 247-253.
Temim, S., Chagneau, A.M., Guillaumin, S., Michel, J., Peresson, R., Geraert, P.A.,  Tesseraud, S. (1999) Effects of chronic heat exposure and protein intake on growth performance, nitrogen retention and muscle development in broiler chickens. Reprod Nutr Dev. 39: 145-156.
Temim, S., Chagneau, A. M., Guillaumin, S., Michel, J., Peresson, R., Tesseraud, S. (2000) Does excess dietary protein improve growth performance and carcass characteristics in heat-exposed chickens? Poult Sci. 79: 312-317.
Yahav, S.A. (2000) Domestic fowl-strategies to confront environmental conditions. Avian Poult Biol Rev. 11: 81-95.