育肥肉雞於合適溫度（22°C至26°C）可達最佳生長性能。然而，在熱帶地區正常環境條件下飼養之肉雞暴露於高溫（30°C以上）下導致熱緊迫。因此，本研究為探討調整飼糧中澱粉與脂肪比例對熱緊迫肉雞之行為、生長性能、屠體性狀及血液的影響。針對15至36日齡肉雞進行兩項試驗，包括飼養試驗及實驗室分析。在32℃ ± 2℃的高溫（區域1）及23℃ ± 2℃的適溫（區域2）條件下，餵飼肉雞不同澱粉脂肪比之飼料（處理1：低脂＝14.69及處理2：高脂＝6.24）。生長試驗採2（溫度）×2（飼糧）複因子設計，隨機分組至每區域，每處理3重複。行為試驗採隨機分組，2飼糧處理組3重複，共計6個實驗組。結果顯示，與處理1的肉雞相比，處理2中肉雞飼料採食量、平均增重和飼料轉換率（FCR）有顯著差異（P＜0.05），但屠體性狀及血液異嗜性白血球與淋巴球比值（heterophils to lymphocytes ratio, H/L ratio）無顯著差異（P＞0.05）。肉雞在高環境溫度（0.45）下喘氣比例顯著（P＜0.05）高於適溫環境溫度（0.15），而在適溫環境溫度下肉雞採食量顯著高於高環境溫度。高脂試驗雞隻飼料採食時間顯著高於低脂試驗雞隻（P＜0.05）。偏好測試中結果顯示，在熱緊迫條件下的肉雞在兩種試驗飼糧中偏好高脂飼糧。因此，在熱緊迫條件下，減少飼糧中澱粉脂肪比例能改善肉雞生長性能並提高生產力。

Finishing broilers grown under thermo-neutral temperatures (22℃ - 26℃) can perform to their optimum growth capacity. However, broilers raised under the normal environmental conditions in Tropical regions are exposed to very high temperatures (above 30℃) leading to heat stress. Therefore, the effects of different dietary starch to lipid ratios on the behaviour, performance, carcass characteristics and blood parameters of broilers under heat stress were evaluated in the present study. Two trials comprising of a feeding trial and laboratory analysis were carried out on broilers aged from 15 to 36 days. The birds were given grower-finisher diets with different starch to lipid ratio (Treatment 1: Low lipid diet = 14.69 and Treatment 2: High lipid diet = 6.24) under cyclic heat stress 32℃ ± 2℃ (block 1) and thermoneutral zone 23℃ ± 2℃ (block 2). A randomised complete block design laid down in a 2 x 2 factorial experiment with 3 replications per treatment diet within block was used for the growth experiment. The behaviour experiment was laid down in a randomised complete block design with two treatment diets, three replicates and a total of six experimental units. Results showed that, there were significant differences (p < 0.05) in the feed intake, average weight gain and FCR of broilers in treatment 2 compared to broilers in treatment 1. The carcass characteristics and heterophil to lymphocyte ratio (H:L ratio) were not significantly affected (p > 0.05) by the treatments. The proportion of birds panting was significantly higher (p < 0.05) under high ambient temperature (0.45) than under normal ambient temperature (0.15) whilst proportion of birds exhibiting feed behaviour was significantly higher under normal temperature than under high temperature A significantly higher proportion of birds were observed on feeders with the high lipid diet than those with the low lipid diet (p < 0.05). Results of preference test indicated that when broilers are offered a choice between the two diets under heat stress conditions they may be able to make their choice based on their preference for high lipid diet. A reduction in dietary starch to lipid ratio may improve broiler performance and increase productivity, under heat stress conditions.

Aftab, U., M. R. Bedford., and D. Creswell. 2018. Prospects of improving efficiency of feed utilisation in broiler. World Poultry Science. Journal. 74(3):427- 442.
Altmann, J. 1974. Observational study of behavior: sampling methods. Behavior. 49(3):227-266.
AOAC. 2005. Official Methods of Analysis of AOAC. International. 18th ed. AOAC International.
Attia, Y. and Hassan, S. 2017. Broiler tolerance to heat stress at various dietary protein/energy levels. European Poultry Science 81(10):1399
Attou, S., G. S. Attou, and K. Bouderoua. 2011. Effects of early and chronic exposure to high temperatures on growth performance, carcass parameters and fatty acids of subcutaneous lipid of broilers. African Journal of Biotechnology 10(57): 12339-12347.
Aviagen. 2018. Broiler management handbook. Available at: http://en.aviagen.com/assets/Tech_Center/Ross_PS/RossPSHandBook20 18.pdf
Baião, N. C., and L. J. C., Lara. 2005. Oil and fat in broiler nutrition. Brazilian Journal of Poultry Science 7(10): 129-141.
Baldemor, A., J. Bocala., G. Manulat., N. Salazar, and A. Angeles. 2018. Potential of In Vitro Α-Amylase And Protease Assays In Evaluating Broiler Diets Supplemented With Multi-Enzyme Product. Philippine Journal of Veterinary and Animal Sciences, 44(2):161-168.
Bokkers E. A. M. and P. Koene. 2003. Behaviour of fast- and slow growing broilers to 12 weeks of age and the physical consequences. Applied Animal Behaviour Science. 81(1): 59-72.
Branco, T., D. J. Moura, I. A. Nääs, and S. R. M. Oliveira. 2019. Detection of broiler heat stress by using the generalised sequential pattern algorithm. Biosystems Engineering. Biosystems Engineering, 199: 121-126.
Brue, R. N, and J. D. Latshaw. 1985. Energy utilization by the broiler chicken as affected by various fats and fat levels. Poultry Science, 64(11):2119-2130.
Burkhart, C. A., J. A. Cherry., H. P. Van Krey, and P. B. Siegel.1983. Genetic Selection tor Growth Rate Alters Hypothalamic Satiety Mechanisms in Chickens. Behaviour Genetics. 13: 295-300
Carré, B., M. Lessire, and H. Juin. 2014. Prediction of the net energy value of broiler diets. Animal, 8(9): 1395-1401.
Chappell, M. A., G. C. Bachman, and K. A. Hammond. 1997. The heat increment of feeding in house wren chicks: magnitude, duration, and substitution for thermostatic costs. Journal of Comparative Physiology B. 167(4):313-318.
Cheng T.K, M.L Hamre and C.N Coon. 1997. Effect of environmental temperature, dietary protein and energy levels on broiler performance. Journal of Applied Poultry Research. 6(1):1-17.
Classen, H. L. 2017. Diet energy and feed intake in chickens. Animal Feed Science Technical. 233:13-21.
Cobb. 2016. Broiler management guide. Cobb - Vantress, Inc.. Available at: http://cobb-vantress.com/docs/default source/managementguides/cobbbreeder-management-guide—english.pdf.
Cooper, M. A., and K. W. Washburn. 1998. The relationships of body temperature to weight gain, feed consumption, and feed utilization in broilers under heat stress. Poultry Science, 77(2):237-242.
Coutinho, J. J. d. O., L. M. Neira., L. C. G. de Sandre., J. I. da Costa., M. I. E. G. Martins., M. C. Portella, and D. J. Carneiro. 2018. Carbohydrate-to lipid ratio in extruded diets for Nile tilapia farmed in net cages. Aquaculture 497:520-525.
Crespo, N. and E. Esteve-Garcia. 2001. Dietary fatty acid profile modifies abdominal fat deposition in broiler chickens. Poultry Science 80:71-78.

Dale, N. M. and H. L. Fuller. 1979. Effects of diet composition on feed intake and growth of chicks under heat stress. 1. Dietary fat levels. Poultry Science 58:1529-1534.
Dale, N. M., and H. L. Fuller. 1978. Effect of ambient temperature and dietary fat on feed preference of broilers. Poultry Science 57:1635-1640.
Dale, N.M. and H.L. Fuller. 1980. Effect of diet composition on feed intake and growth of chicks under heat stress, 11. Constant vs. cycling temperature. Poultry Science, 59:1434-1441.
Danicke, S., W. Vahjen., O. Simon, and H. Jeroch. 1999. Effects of dietary fat type and xylanase supplementation to rye-based broiler diets on selected bacterial groups adhering to the intestinal epithelium. on transit time of feed, and on nutrient digestibility. Poultry Science, 78(9):1292-1299.
De Groote, G. 1974. A comparison of a new net energy system with the metabolisable energy system in broiler diet formulation, performance and profitability. British Poultry Science 15(1):75-95.
de Queiroz, J. P. J. B. de Souza, H. F. Jr. de Lima, M. K. de Oliveira Costa, L. L. de Macedo Costa, and A. M. de Arruda. 2014. Daily variations in the thermoregulatory behaviors of naked neck broilers in an equatorial semiarid environment. International Journal of Biometeorology 58:1259-1264.
Dey B., F. Kawabata, Y. Kawabata, S. Nishimura, and S. Tabata. 2017. Identification of Functional Bitter Taste Receptors and Their Antagonist in Chickens. Biochemical and Biophysical Research Communications. 482: 693-699
Dubois, M., K. A. Gilles, J. K. Hamilton, P. A. Rebers, and F. Smith. 1956. Colorimetric method for determination of sugars and related substances. Analytical Chemistry 28:350-356.
Duncan, D.D. 1955. Multiple range and multiple ‘F’ test. Biometrics 11:1-42
Dziedzic, S. Z. and M. W. Kearsley. 1995. Handbook of starch hydrolysis products and their derivatives. London: Blackie Academic & Professional. 230. ISBN 978-0-7514-0269-8.
Edgar, J. L., Nicol, C. J., Pugh, C. A., and Paul, E. S. 2013. Surface temperature changes in response to handling in domestic chickens. Physiology & behavior, 119:195-200.
Elferink, M., and F. Schierhorn. 2016. Global Demand for Food is Rising. Can we meet it. Harvard Business Review 7(04).
Emmans, G. C. 1994. Effective energy: a concept of energy utilization applied across species. Brazilian Journal of Nutrition 71(6):801-821.
Farmer’s Weekly. 2014. Broilers: SA vs Argentina
https://www.farmersweekly.co.za/animals/cattle/broilers-sa-vs-argentina/
Fascina, V. B., A. S. Carrijo, K. M. R. Souza, A. M. L. Garcia, C. Kiefer, and J. R. Sartori. 2009. Soybean oil and beef tallow in starter broiler diets. Brazilian Journal of Poultry Science 11(4):249-256.
Forbes, J. M. 1995. Voluntary Food Intake and Diet Selection in Farm Animals. CAB International, Wallingford, UK.
Fouad, A. M, and H. K. El-Senousey. 2014. Nutritional factors affecting abdominal fat deposition in poultry: a review. Asian-Australasian journal of animal sciences 27(7):1057.
Fuller, H., and M. Rendon. 1977. Energetic efficiency of different dietary fats for growth of young chicks. Poultry Science 56(2):549-557.
Fuller, H., and M. Rendon. 1979. Energetic efficiency of corn oil and poultry fat at different levels in broiler diets. Poultry Science 58(5):1234-1238.
Geraert P. A., J. C. F. Padilha, S. Guillaumin. 1996. Metabolic and endocrine changes induced by chronic heat exposure in broiler chickens: Growth performance, body composition and energy retention. British Journal of Nutrition. 75(2):195-204.
Ghazalah, A. A., M. O. Abd-Elsamee, and A. M. Ali. 2008. Influence of dietary energy and poultry fat on the response of broiler chicks to heat therm. International Journal of Poultry Science 7(4):355-359.
Golian, A., and D. V. Maurice. 1992. Dietary poultry fat and gastrointestinal transit time of feed and fat utilization in broiler chickens. Poultry science, 71(8):1357–1363.
Gusakov, A. V., E. G. Kondratyeva, and A. P. Sinitsyn. 2011. Comparison of Two Methods for Assaying Reducing Sugars in the Determination of Carbohydrase Activities. International Journal of Analytical Chemistry (3):1- 4.
Hassan, S. S., and Y. A. Attia. 2018. Effect of increasing dietary vegetable oils concentration on performance, carcass parameters and blood constituents of broiler chickens exposed to high ambient temperature. Rev. Mex. Cienc. Pecu. (9):2
He, S. P., M. A. Arowolo., R. F. Medrano., S. Li., Q. F. Yu, Q., J. Y. Chen., and J. H. He. 2018. Impact of heat stress and nutritional interventions on poultry production. World Poultry Science Journal 74(4):647-664.
Hetland, H., and B. Svihus. 2001. Effect of oat hulls on performance, gut capacity and feed passage time in broiler chickens. Brazilian Poultry Science. 42:354–361.
Hoffmann G., H. Völker., J. R. M. Arenillas. 1968. Anatomía y fisiología de las aves domésticas. Zaragoza: Acribia.
Huxley, J. S. 1932. Problems of relative growth. Lincoln Mac Veagh-The Dial Press, New York.
Huxley, J. S., and G. Teissier. 1936. Terminology of relative growth. Nature, 137780-137781
Infante-Rodríguez, F., J. Salinas-Chavira, M. Montaño-Gómez, O. Manríquez-Nuñez, V. González-Vizcarra, O. Guevara-Florentino and J.R.J.S. De León. 2016. Effect of diets with different energy concentrations on growth performance, carcass characteristics and meat chemical composition of broiler chickens in dry tropics. Poultry Science 5(1):1937.
Keeling, L. J., and J. F. Hurnik. 1996. Social facilitation acts more on the appetitive than the consummatory phase of feeding behaviour in domestic fowl. Animal Behavior. 52:11–15.
Khoddami, A., P. V. Chrystal., P. H. Selle., and S. Y. Liu. 2018. Dietary starch to lipid ratios influence growth performance, nutrient utilisation and carcass traits in broiler chickens offered diets with different energy densities. PLoS One. 13(10).
Leeson S, and J. D. Summers. 2001. Nutrition of the chicken. 4th ed. Ontario: University Books:413.
Li, D., R. Thaler., J. Nelssen., D. Harmon., G. Allee., and T. Weeden. 1990. Effect of fat sources and combinations on starter pig performance, nutrient digestibility and intestinal morphology. Journal of Animal Science. 68:3694-704.
Lin, H., H. F. Zhang, R. Du, X. H. Gu, Z. Y. Zhang, J. Buyse, and E. Decuypere. 2005. Thermoregulation responses of broiler chickens to humidity at different ambient temperatures. II. Four weeks of age. Poultry science, 84(8):1173-1178.
Linden, J. 2013. GLOBAL POULTRY TRENDS 2013: Africa's Chicken Growth Exceeds World Average. The Poultry Site. https://www.thepoultrysite.com/articles/global-poultry-trends-2013-africas-chicken-growth-exceeds-world-average
Liu SY, P. H. Selle, D. Raubenheimer, R. M. Gous, P. V. Chrystal, D. J. Cadogan, et al. 2017. Growth performance, nutrient utilisation and carcass composition respond to dietary protein concentrations in broiler chickens but responses are modified by dietary lipid levels. Brazilian Journal of Nutrition 118(4):250–262.
Lott, B. D., W. A. Dozier, J. D. Simmons and W. B. Roush. 2003. Water flow rates in commercial broiler houses. Poultry Science 82(1):102.
Mahmoud, U. T., M. A. M. Abdel-Rahman, M. H. A. Darwish, T. J. Applegate, and H. W. Cheng. 2015. Behavioral changes and feathering score in heat stressed broiler chickens fed diets containing different levels of propolis. Applied Animal Behavior Science 166:98-105.
Malheiros, R., D. V. M Moraes, A. Collin, E. Decuypere, and J. Buyse. 2003. Free diet selection by broilers as influenced by dietary macronutrient ratio and corticosterone supplementation. Diet selection, organ weights, and plasma metabolites, Poultry Science 82(1):123–131.
Malheiros, R., D. V. M Moraes, A. Collin, E. Decuypere, and J. Buyse. 2003a. Dietary macronutrients, endocrine functioning and intermediary metabolism in broiler chickens: Pair wise substitutions between protein, fat and carbohydrate. Nutrition Research. 23(4):567–578.
Marchini, C. F. P., E. A. Fernandes, M. R. B. M. Nascimento, E. G. Araújo, E. C. Guimarães, J. P . R. Bueno, N. S. Fagundes, and M. B. Café. 2018. The Effect of Cyclic Heat Stress Applied to Different Broiler Chicken Brooding Stages on Animal Performance and Carcass Yield. Brazilian Journal of Poultry Science, 20:765-772.
Marsden, W. L., P. P. Gray., G. J. Nippard and M. R. Quinlan. 2007. Evaluation of the DNS method for analysing lignocellulosic hydrolysates. Journal of Chemical Technology and Biotechnology, 32:7-12.
Masuku, M. B. 2011. An analysis of the broiler supply chain in Swaziland: A case study of the Manzini Region. Asian Journal of Agricultural Sciences, 3(6): 492-499.
Mateos, G. G., J. L. Sell, and J. A. Eastwood. 1982. Rate of food passage (transit time) as influenced by level of supplemental fat. Poultry Science, 61(1):94-100.
Maxwell, M. H. 1993. Avian blood leucocyte responses to stress. World's Poultry Science Journal, 49(1): 34-43.
Miller, G.L. 1959. Use of dinitrosalicylic acid reagent for determination of reducing sugar. Journal of Analytical Chemistry 31:426
Nääs, I. A., C. E. B., Romanini., D. P. Neves., G. R., Nascimento, and A. R. Vercellino. 2010. Broiler surface temperature distribution of 42 day old chickens. Scientia Agricola, 67(5):497-502.
National Research Council (US). 1981. Subcommittee on Environmental Stress. Effect of Environment on Nutrient Requirements of Domestic Animals. Washington (DC): National Academies Press (US); Feed Intake.
National Research Council. 1994. Nutrient Requirements of Poultry. 9th edition. National Academic Press, Washington, DC.
Nielsen, B. L. 2004. Behavioural aspects of feeding constraints: do broilers follow their gut feelings? Applied Animal Behaviour Science 86(3):251260.
Neves, D. P., T. M. Banhazi, and I. A. Nääs. 2014. Feeding behaviour of broiler chickens: a review on the biomechanical characteristics. Brazilian Journal of Poultry Science, 16(2), 01-16.
Noy, Y., and D. Sklan. 1995. Digestion and absorption in the young chick. Poultry science 74(2):366–373.
Official, A. O. A. C. 2005. Methods of analysis of AOAC International. AOAC International.18th ed.
Pelletier, N., and P. Tyedmers. 2010. Forecasting potential global environmental costs of livestock production 2000–2050. Proceedings of the National Academy of Sciences, 107(43):18371-18374.
Piao, M. Y., H. J. Lee., H. I. Yong, S. H. Beak, H. J. Kim, C. Jo, K. G. Wiryawan and Baik, M. 2019. “Comparison of reducing sugar content, sensory traits, and fatty acids and volatile compound profiles of the longissimus thorasic among Korean cattle, Holsteins, and Angus steers.” Asian-Australasian Journal of Animal Sciences 32(1):126-136. doi:10.5713/ajas.18.0065
Pousga S, H. BolY, and B. Ogle. 2005. Choice feeding of poultry: a review. Livestock Research for Rural Development. Vol. 17, Art. #45. Retrieved: July,09,2021,from http://www.lrrd.org/lrrd17/4/pous17045.htm
Ravindran, V., P. Tancharoenrat., F. Zaefarian., and G. Ravindran. 2016. Fats in poultry nutrition: Digestive physiology and factors influencing their utilisation. Animal Feed Science and Technology Journal 213:1-21.
Rosa, PS., D. E. Faria Filh., F. Dahlke., B. S.Vieira., M. Macari, and R. L. Furlan. 2007. Performance and carcass characteristics of broiler chickens with different growth potential and submitted to heat stress. Brazilian Journal of Poultry Science 9(3):181-186.
Sadeghi, G. H., and S. A. Tabiedian. 2005. Effect of different energy to protein ratio and tallow supplementation on broiler performance. International Journal of Poultry Science 4:976-981.
Sakomura, N., A. Longo., E. Oviedo-Rondón., Boa-Viagem, and A. Ferraudo. 2005. Modelling energy utilisation and growth parameter description for broiler chickens. Poultry Science Journal (17):1363 -1369.
Sanz, M., A. Flores, and C. J. Lopez-Bote. 2000. The metabolic use of energy from dietary fat in broilers is affected by fatty acid saturation. Brazilian Poultry Science Journal 41(1):61-68.
Sanz, M., A. Flores, and C. J. Lopez-Bote. 2000a. The metabolic use of energy from dietary fat in broilers is affected by fatty acid saturation. British Poultry Science 41:61-66.
Sanz, M., C. J. Lopez-Bote, D. Menoyo, and J. M. Bautista. 2000b. Abdominal fat deposition and fatty acid synthesis are lower and β-oxidation is higher in broiler chickens fed diets containing unsaturated rather than saturated fat. Journal of Nutrition. 130:3034-3037.
Savory, C. J, and J. P. Hodgkiss. 1984. Influence of vagotomy in domestic fowls on feeding activity, food passage, digestibility and satiety effects of two peptides. Physiology & behavior. 33(6):937-944.
Savory, C. J. 1981. Correlations between meals and inter-meal intervals in Japanese quail and their significance in the control of feeding. Behavioural Processes, 6(1):23-36.
Scott, M. L., M. Nesheim., and R. J. Young. 1992. Nutrition of the chicken. Fifth Ed. Scott, M. L. and Associates. New York: Ithaca.
Silva, H. G. de O., A. J. V Pires, P. A. Cunha Neto, G. G. P. de Carvalho, C. M. Veloso, and F. F. da Silva. 2007. Digestibility of nutrients in diets containing ammoniated elephant grass and cocoa meal or palm kernel cake fed to sheep. Rev. Bras. Zootec., 36 (2): 499-506
Sklan, D., and Y. Noy. 2000. Hydrolysis and absorption in the small intestines of post hatch chicks. Poultry Science, 79(9):1306-1310.
Svihus, B. 2014. Function of the digestive system. Journal of Applied Poultry Research, 23:1-9.
Svihus, B. and H. Hetland. 2001. Ileal starch digestibility in growing broiler chickens fed on a wheat-based diet is improved by mash feeding, dilution with cellulose or whole wheat inclusion. British Poultry Science, 42(5):633-637.
Syafwan, S., G. J. D. Wermink, R. P. Kwakkel, and M. W. A. Verstegen. 2012. Dietary self-selection by broilers at normal and high temperature changes feed intake behavior, nutrient intake, and performance. Poultry Science 91:537–549.
Symeon, G. K., C. Zintilas, N. Demiris, I. A. Bizelis, and S. G. Deligeorgis. 2010. Effects of Oregano essential oil dietary supplementation on the feeding and drinking behaviour as well as the activity of broilers. International Journal of Poultry Science 9:401-405.
Tolkamp, B. J., D. J. Allcroft, J. P. Barrio, T. A. Bley, J. A. Howie, T. B. Jacobsen, C. A. Morgan, D. P. Schweitzer, S. Wilkinson, M. Yeates, and I. Kyriazakis. 2011. The temporal structure of feeding behavior. American Journal of Physiology. Regulatory, Integrative and Comparative Physiology. 301:378-93. 10.1152/ajpregu.00661.2010,
Tripathi, A. D., R. Mishra, K. K. Maurya, R. B. Singh, and D. W. Wilson. 2019. Estimates for world population and global food availability for global health. In: The role of functional food security in global health:3-24. Academic Press.
Vieira, SL, Viola, ES, Berres, J, Olmos, AR, Conde, ORA, and Almeida, JG. 2006. Performance of broilers fed increased levels energy in the pre-starter diet and on subsequent feeding programs having with acidulated soybean soapstock supplementation. Brazilian Journal of Poultry Science, 8(1):55-61
Weng R. C. 2017. Dietary fat preference and effects on performance of piglets at weaning. Asian-Australasian Journal of Animal Sciences, 30(6):834–842. https://doi.org/10.5713/ajas.16.0499
Witt, F. H., S. P.de, Els, H. J. van der Merwe, A. Hugo, and M. D. Fair. 2009. Effect of dietary lipid sources on production performance of broilers. South African Journal of Animal Science, 39:45-48.
Zelenka, J., and Z. Ceresnakova. 2005. Effect of age on digestibility of starch in chickens with different growth rate. Czech Journal of Animal Science, 50:411-415.
Zulkifli, I., N. N. Htin, A. R. Alimon, T. C. Loh, and M. Hair-Bejo. 2006. Dietary selection of fat by heat-stressed broiler chickens. Asian-Australasian Journal of Animal Sciences, 20(2): 245-251.