Thermoregulation responses of broiler chickens to humidity

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Thermoregulation responses of broiler chickens to humidity

  1. 1. Thermoregulation Responses of Broiler Chickens to Humidityat Different Ambient Temperatures. II. Four Weeks of AgeH. Lin,*†,1 H. F. Zhang,† R. Du,† X. H. Gu,† Z. Y. Zhang,† J. Buyse,‡ and E. Decuypere‡*Department of Animal Science, Shandong Agricultural University, Taian, Shandong 271018, PR China;†Instituteof Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100094, PR China; and ‡Lab of Physiologyand Immunology of Domestic Animal, Department of Animal Science, Kasteelpark Arenberg 30, 3001 Heverlee,BelgiumABSTRACT Two experiments were conducted to investigatethe effect of RH (35, 60, and 85%) on thermoregulationof broiler chickens at high (35°C) and mild (30°C)temperatures at the age of 4 wk. The effects of humidityon rectal temperature (RT) and plumage temperature atback (PBAT) and skin temperature at breast (SBRT) weredetermined at 1, 4, 8, 16, and 24 h after exposure. TheRT, PBAT, and SBRT were all significantly increased byhigh temperature (35°C). Humidity had a significant influenceon RT at 35°C but not at 30°C. The peripheraltemperatures (PBAT and SBRT) were significantly affectedby humidity but responded differently at high(35°C) compared with mild temperature (30°C). In conclu-(Key words: thermoregulation, broiler chicken, humidity, ambient temperature)2005 Poultry Science 84:1173–1178INTRODUCTIONThe effect of humidity on the zootechnical performanceof broiler chickens seems to be dependent onambient temperature. Yahav et al. (1995) reported thatmaximal growth rate and feed intake of broiler chickensat 35°C were observed at 60 to 65% RH between theages of 4 and 8 wk. Humidity also has an effect ongrowth performance of broiler chickens at slightly elevatedambient temperature (28 and 30°C) (Yahav, 2000).For broiler chickens, absolute growth rate increases withage and reaches maximum between 4 and 5 wk of ageand decreases thereafter (Scheuermann et al., 2003). Theintensive genetic selection for fast growth rate meansthat modern species of broiler chickens are very susceptibleto heat stress (Deeb and Cahaner, 2002). Hence,it is of interest to know the effect of humidity on thethermoregulation of broiler chickens during rapid absolutegrowth.In our previous study using broiler chickens of 1 wkof age, humidity had an effect on the thermoregulationo 2005 Poultry Science Association, Inc.Received for publication December 2, 2004.Accepted for publication May 5, 2005.1To whom correspondence should be addressed: hailin@sdau.edu.cn.1173sion, high humidity above 60% impaired the heat transmissionfrom body core to the periphery at 35°C butfacilitated it at 30°C in4-wk-old broiler chickens. The effectof humidity on nonevaporative heat loss was dependedon air temperature, as nonevaporative heat losswas suppressed by high humidity (>60% RH) at hightemperature but enhanced at the mild temperature. Theeffect of humidity on the relationship between peripheraland core temperature depends on ambient temperatureas well as on the age of the broiler chicken. The disturbanceof thermal balance could not be determined onlyby changes in RT or peripheral temperature at a singletime point but could be determined by mean body temperaturewithin a certain time frame.at high, low, and even moderate temperatures (Lin et al.,2005). The temperature requirement of broiler chickensdecreases (Lin et al., 2004b) and the susceptibility to heatincreases with age and body weight (Sandercock et al.,2001; Yalcˆin et al., 2001). Moreover, the relative growthrate of broiler chickens decreases with age (Scheuermannet al., 2003). So we hypothesized that the effectof humidity on thermoregulation at high temperaturewould change with age of broiler chickens and that olderchickens would respond differently from young chickens,
  2. 2. as they have different growth characteristics andheat susceptibility. On the other hand, in our perviousstudy, it was shown that change in humi dity could triggerthe redistribution of heat within body of 1- wk-oldbroiler chickens (Lin et al., 2005). Whether these pheno m e nacould be induce d in 4-wk-old broiler chickensneed s to be investigated further.The objectives of the present study were to evaluatethe effect of humi dity on the thermoregulatory responseof 4-wk-old broiler chickens at high temp erature and toinvestigate whether the thermoregulation response ofAbbreviation Key: NEHL = nonevaporative heat loss; PBAT = surfacetemperature of plumage at back; SBRT = skin temperature at breast;RT = rectal temperature; VP = vapor pressure.1174 LIN ET AL.broiler chickens to humidity was changed with age, aspresented elsewhere (Lin et al., 2005). In the presentstudy, 2 experiments were conducted to evaluate theeffects of humidity on the thermoregulation of 4-wk-oldbroiler chickens at high (35°C) or mild (30°C) temperature.The plumage temperature at back (PBAT) and theskin temperature at breast (SBRT) were measured todetermine the surface temperature, whereas the rectaltemperature was used to estimate the core temperature.MATERIALS AND METHODSBird and DietsArbor Acres broiler chicks were obtained from a commercialhatchery at 1 d of age and were raised in batterybrooders located in an environmentally controlled room.The temperature wasmaintained at 35°C during the first3 d and then decreased gradually to 20°C (40% RH) by28 d of age and maintained as such thereafter. The heatexposure experiment was conducted in 4 environmentalchambers equipped with computerized temperature(±0.5°C) and humidity controllers (RH ±5%) as describedby Lin et al. (1996a,b). The 4 environmental chamberswere identical in terms of size, constructing materials,climatization equipment, cages, feeders, and drinkers.During rearing or the heat exposure period, broilerchickens had free access to water and feed. The lightingschedule provided 24 h of light per day. The chicks werefed a standard commercial starter diet (3,100 kcal ofME/kg and 22.3% CP) from d 0 to 21 and a finisher diet(3,100 kcal of ME/kg and 19.4% CP) from d 22 onward.All diets were fed as mash and formulated according tothe recommendations of National Research Council(1994).TreatmentsTrial 1. Forty broiler chickens of both sexes were selectedat 28 d of age. All chickens were assigned randomlyto 4 groups of 10 chickens by sex and body weightto have equal numbers of males and females with similarmean body weight (1,050 ± 39 g) in each group. After24 h of acclimation in the climatic chambers (21°C, 60%RH), the broilers were randomly exposed to 1 of the 4thermal environments for 24 h, which were 21°C and60% RH vapor pressure [(VP), 1,484 Pa], 35°C and 35%RH (VP, 1,952 Pa), 35°C and 60% RH (VP, 3,346 Pa),and 35°C and 85% RH (VP, 4,740 Pa). The designatedtemperature and humidity values were reached within30 min.Trial 2.At 28 d of age, thirty broilers of both sexes weredivided into 3 groups of 10 broiler chickens according tosex and body weight to have equal numbers of malesand females with similar mean body weights in eachgroup (1,057 ± 40 g). The experimental chickens were2Qinghua University, Beijing, PR China.exposed to 1 of the 3 environmental treatments for 24h, which were 30°C and 35% RH (VP, 1,474 Pa), 30°Cand 60% RH (VP, 2,527 Pa), and 30°C and 85% RH (VP,3,580 Pa), respectively. The designated temperature andhumidity values were obtained within 30 min.Measurements
  3. 3. In both trials, the experim ental chicks were expose dto different thermal treatments at 0800 h, and the rectaltemp erature (RT), PBAT, and SBRT of each chicken wererecorded at 1 h (0900 h), 4 h (1200 h), 8 h (1600 h), 16 hREFERENCESBelay, T., and R. G. Teeter. 1993. Broiler water balance andthermobalance during thermoneutral and high ambienttemperature exposure. Poult. Sci. 72: 116–124.Chwalibog, A., and B. O. Eggum. 1989. Effect of temperatureon performance, heat production, evaporative heat loss andbody composition in chickens. Arch. Geflu¨ gelkd. 53:179–184.Corbit, J. T. (1973) Voluntary control of hypothalamic temperature.J. Comp. Physiol. Psychol. 83:394–411.Deeb, N., and A. Cahaner. 2002. Genotype-by-environmentinteraction with broiler genotypes differing in growth rate.3. Growth rate and water consumption of broiler progenyfrom weight-selected versus nonselected parents undernormal and high ambient temperatures. Poult. Sci.81:293–301.Frank, S. M., S. N. Raja, C. F. Bulcao, and D. S. Goldstein. 1999.Relative contribution of core and cutaneous temperaturesto thermal comfort and autonomic responses in humans. J.Appl. Physiol. 86:1588–1593.Iwase, S., J. Cui, B. G. Wallin, A. Kamiya, and T. Mano. 2002.Effects of increased ambient temperature on skin sympatheticnerve activity and core temperature in humans. Neurosci.Lett. 327:37–40.Kato, M., J. Sugenoya, T. Matsumoto, T. Nishiyama, N. Nishimuta,Y. Inukai, T. Okagawa, and H. Yonezawa. 2001. Theeffects of facial fanning on thermal comfort sensation duringhyperthermia. Pflugers Arch. 443:175–179.Lin, H., J. Buyse, R. Du, X. H. Du and Z. Y. Zhang, 2004a.Response of rectal temperature of broiler chickens to thermalenvironmental factors. Arch. Geflu¨ gelkd. 68:126–131.Lin, H., R. Du, X. H. Gu, and Z. Y. Zhang. 1996a. The effectsof thermal environment on the growth of neonatal chicks:I. The development of thermoregulation. J. Anim. Physiol.Anim. Nutr. 75:200–206.Lin, H., R. Du, X. H. Gu, and Z. Y. Zhang. 1996b. The effectsof thermal environment on the growth of neonatal chicks:II. The development of viscera organs. J. Anim. Physiol.Anim. Nutr. 75:207–213.Lin, H., R. D. Malheiros, V. M. B. Moraes, C. Careghi, E. Decuypere,and J. Buyse. 2004b. Acclimation of broiler chickensto chronic high environmental temperature. Arch.Geflu¨ gelkd. 68:39–46.Lin, H., H. F. Zhang, H. C. Jiao, T. Zhao, S. J. Sui, Z. Y. Zhang,J. Buyse, and E. Decuypere. 2005. Thermoregulation responsesof broiler chickens to humidity at different ambienttemperatures. I. OneWeek of Age. Poult. Sci. 84:1166–1172.Nichelmann, M., B. Tzschentke, andA. Burmeister. 1991. Evaporativewarmeabgabe des geflugels bei hoher relativer luftfeuchtigkeit.Arch. Geflu¨ gelkd. 55:110–115.National Research Council. 1994. Nutrient Requirements ofPoultry. 9th rev. ed. National Academy Press, Washington,DC.Sakurada, S., O. Shido, K. Fujikake, and T. Nagasaka. 1993.Relationship between body core and peripheral temperaturesat the onset of thermoregulatory responses in rats.Jpn. J. Physiol. 43:659–667.Sandercock, D. A., R. R Hunter, G. R. Nute, M. A. Mitchell,and P. M. Hocking. 2001. Acute heat stress-induced alterationsin blood acid-base status and skeletal muscle membraneintegrity in broiler chickens at two ages: Implicationsfor meat quality. Poult. Sci. 80:418–425.SAS Institute, 1986. SAS User˜s Guide: Statistics. SAS Institute,Cary, NC.Scheuermann, G. N., S. F. Bilgili, J. B. Hess, and D. R. Mulvaney.2003. Breast muscle development in commercial broilerchickens. Poult. Sci. 82: 1648–1658.Sessler,D. I., andA.Moayeri. 1990. Skin-surfacewarming: heatflux and central temperature. Anesthesiology 73:218–224.Whittow, G. C. 1986. Regulation of Body Temperature. Page221–252 in Avian Physiology. P. D. Sturkie, ed. Springer-Verlag, New York.Yahav, S. 2000. Relative humidity atmoderate ambient temperatures;its effect on male broiler chickens and turkeys. Br.Poult. Sci. 41:94–100.Yahav, S., S. Goldfeld, I. Plavnik, and S. Hurwitz. 1995. Physiologicalresponses of chickens and turkeys to relative humidityduring exposure to high ambient temperature. J. Therm.Biol. 20:245–253.Yahav, S., A. Straschnow, I. Plavnik, and S. Hurwitz. 1997.Blood system responses of chickens to changes in environmentaltemperature. Poult. Sci. 76:627–633.Yalcˆin, S., S. O¨ zkan, L. Tu¨ rkmut, and P. B. Siegel. 2001. Responsesto heat stress in commercial and local broiler stocks.1. Performance traits. Br. Poult. Sci. 42:149–152.Zhou, W. T., and S. Yamamoto. 1997. Effects of environmentaltemperature and heat production due to food intake on
  4. 4. abdo minal temperature, shank skin temperature and respirationrate of broilers. Br. Poult. Sci. 38:107– 1 1Thermoregulatory Responses of Chicks(Gallus domesticus) to Low AmbientTemperatures at an Early Age1 1. D. Shinder*,2, 2. M. Rusal*, 3. J. Tanny†, 4. S. Druyan‡ and 5. S. Yahav*+ Author Affiliations * 1. Institute of Animal Science, the Volcani Center, Bet Dagan 50250, Israel; †Institute of Soil, Water and Environmental Sciences, Agricultural Research Organization, the Volcani Center, Bet Dagan 50250, Israel; and ‡The Hebrew University of Jerusalem, Faculty of Agricultural, Food and Environmental Quality Sciences, Rehovot 76100, Israel 1. ↵2Corresponding author: dshinder@agri.huji.ac.ilNext SectionAbstractThe potential to induce improved thermotolerance in broiler chickens is of great importance.Thermal conditioning is one of the management tools used to improve thermotolerance, enablingbroilers to cope with extreme environmental conditions. This study investigated the effects ofexposing chicks to low ambient temperature (Ta) on-chick body (Tb), surface (Ts) temperaturesand total sensible heat loss (SHL) by convection and radiation from the body and from 2 mainradiative organs, the face and the legs. At 3, 4, or at both 3 and 4 d of age, chicks were exposedto 5°C for 1.5 h a day (to avoid mortality) or to 10 or 15°C for 3 h a day. In general, in alltreatments, the results during exposure to cold differed significantly from the control. A secondcold exposure (on d 4 after a first exposure on d 3) clearly enhanced the chicks’ ability tomaintain on-chick body surface temperatures during exposure to 15°C and to recover muchfaster from cold exposure. A dramatic decline in average surface temperature was observedduring the first 15 min of chicks’ exposure to the various low ambient temperatures in all ages,reaching the lowest values in the 5°C treated chicks. The face responded immediately to cold
  5. 5. exposure by significantly increasing its SHL to a level that then remained relatively steady(15°C) or declined moderately with time (10 and 5°C). In the legs, however, a significant andcontinuous decline in SHL was exhibited in all ages. The dynamics of SHL from the legsdiffered from that from the face, suggesting that the legs are a major organ for vasomotorresponses, whereas the face is a more conservative vasoregulatory organ. It is concluded thatrepetitive exposure to cold may enhance thermotolerance, and that this is partially related to thevasomotor responses. This is the first report quantifying the differentiation between the legs as aresponsive vasomotor organ and the face as a conservative vasomotor one. • body temperature • chick • cold exposure • sensible heat loss • thermotolerancePrevious SectionNext SectionINTRODUCTIONThe potential to induce improved thermotolerance in broiler chickens is of great importance,particularly in view of the effectiveness in the development of genetic selection for improvedmeat production in broilers (Havenstein et al., 2003). That has made it more difficult for broilersto cope with extreme environmental conditions (Yahav, 2000). Thermal conditioning is one ofthe management tools that partially enable broilers to cope with extreme environmentalconditions. This technique takes advantage of the immaturity of the temperature-regulationmechanism in chicks during their first week of life (Dunnington and Siegel, 1984; Modrey andNichelmann, 1992), a mechanism that involves sympathetic neural activity, integration ofthermal information in the hypothalamus (Rothwell, 1992), and buildup of the body-braintemperature difference (Arad and Itsaki-Gluklish, 1991). Thus, induction of thermotolerance canpotentially be incorporated into developing thermoregulation mechanisms. For example, heatconditioning in the first week of life has been shown to considerably improve the chick’s abilityto subsequently cope with exposure to acute heat stress by causing a significant decline in heatproduction (Yahav and Hurwitz, 1996), coupled with increased sensible heat loss (SHL) viaradiation and convection (Yahav et al., 2005).Cold conditioning applied to bantam chicks has also been shown to improve thermoregulatorycapacity in faster growth chicks (Aulie, 1977). Shinder et al. (2002) demonstrated that repeatedshort periods of cold conditioning during the first week of life improves the ability of chicks tocope with low ambient temperature (Ta). However, in the first week of life, when the bodysurface-to-volume ratio is relatively high, how broiler chicks respond thermally to coldconditioning is unknown, especially considering the effects of SHL.The main driving force for SHL is the temperature difference between body surface temperature(Ts) and Ta. One of the main impediments to quantifying SHL has been the inability to accuratelymeasure the animal’s Ts distribution and to differentiate between the contributions of differentsurface regions to heat loss. However, recently, infrared thermometry has been used successfully
  6. 6. to measure Ts in mammals (Mohler and Heath, 1988; Klir et al., 1990; Klir and Heath, 1992;Phillips and Heath, 1992) and in birds (Phillips and Sanborn, 1994; Yahav et al., 1998, 2004,2005).The present study was designed to elucidate the effects of exposing chicks at an early stage oflife to low Ta on their body temperature (Tb) and on total SHL via convection and radiation, toquantify SHL from the body and from 2 main radiative organs, the face and the legs.Previous SectionREFERENCES 1. ↵ Arad, Z. 1991. Ontogeny of brain temperature regulation in chicks (Gallus gallus domesticus). Br. Poult. Sci. 32:203–210. MedlineWeb of Science 2. ↵ Arad, Z., and S. Itsaki-Gluklish. 1991. Ontogeny of brain temperature in quail chicks (Coturnix coturnix japonica). Physiol. Zool. 64:1356–1370. 3. ↵ Aulie, A. 1977. The effect of intermittent cold exposure on the thermoregulatory capacity of bantam chicks Gallus domesticus. Comp. Biochem. Physiol. 56A:545–549. 4. ↵
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