Effect Of Acute Moderate Temperatures On Behavior,Physiology And Biochemical,avUCP MRNA Expression Of Broilers

With the continuous improvement of control technology on indoor temperature and humidity,stress induced by constant high temperature reduced.However,acute stress usually appeared which was caused by abrupt rise in temperature in moderate environment when summer is coming in China,seriously affecting health status and growth performance of broilers.Therefore,the effects of acute moderate temperature on broilers received extensive attention.The experiment was conducted to investigate the effects of acute moderate temperature on behavior,physiology,acid-base balance,glycolipids metabolism and uncoupling protein,which is expected to provide information for furnishing broilers with comfortable environment.The experiment studied that broilers was exposed to four acute moderate temperature（23,26,29,32℃）for 30 minutes or 2 hours,determining behavior,physiology,biochemistry and molecular changes,to analyze the effects of acute moderate temperature on rest,activity,core body temperature,skin temperature and mRNA of avUCP in breast muscle and liver of broilers.Ambient temperature of23 ℃,relative humidity of 35%,60%,85%,broiler by acute stress 2h,detection of the same indicators.The main results are as follows:1 Effects of different ambient temperature on behavior,physiology and biochemistry,uncoupling protein of broilers.Test conditions of 23℃ significantly increased stretching and resting of broilers（P<0.05）,while standing frequency was significantly decreased（P<0.05）.The expression of avUCP m RNA in broiler was significantly decreased（P<0.05）.Test conditions of26℃significantly increased Core body temperature,respiratory rate,and skin temperature of broilers（P<0.05）,but there was no significant difference in TC（P>0.05）.The resting frequency of broilers was significantly increased（P<0.05）,the sitting frequency of resting was decreased（P<0.05）.The expression of avUCP mRNA in broiler was significantly decreased（P<0.05）.Test conditions of 29℃significantly increased Core body temperature,respiratory rate,and skin temperature of broilers（P<0.05）,Serum GLU and TC were significantly decreased（P<0.05）.Drinking water frequency increased（P <0.05）,and the frequency of activities（feeding and standing）decreased（P<0.05）.The expression of avUCP mRNA in broiler was significantlydecreased（P <0.05）.Test conditions of 32℃significantly increased Core body temperature,respiratory rate,and skin temperature of broilers（P<0.05）,Serum TC content decreased（P<0.05）.The frequency of sitting and resting decreased（P<0.05）;The expression of avUCP mRNA in broiler was significantly decreased（P<0.05）and increased in liver（P <0.05）.Test conditions of 35℃significantly increased respiratory rate,,and skin temperature of broilers（P <0.05）,the frequency of stretching was significantly increased（P<0.05）.The frequency of sitting and resting decreased significantly（P<0.05）.This indicates that behavior regulation started from 23℃to keep homeostasis;rise in core body temperature started from 26℃ to keep homeostasis;significantly decreases in mRNA expression of avUCP in breast muscle started from23℃ to keep homeostasis.2 The effects of different humidity（35%,60%,85%）at the same temperature（23 ℃）on behavior,physiology and biochemistry.Test conditions of 23℃treatment,Compared with medium humidity（60%）,the body temperature and body temperature of broilers decreased significantly（P<0.05）,while the temperature of Leg and Earlobe did not differ significantly（P>0.05）0.05).Serum T₃,T₄ and GLU were significantly decreased（P<0.05）,TG and TC increased significantly（P<0.05）,but CORT had no significant difference（P>0.05）.Resting behaviors（sitting,stretching,prostrating）had no significant difference（P>0.05）.High temperature（85%）treatment significantly increased Comb and leg temperature in broilers（P<0.05）.serum TG and TC were significantly increased（P<0.05）;the respiratory rate was significantly increased（P<0.05）;the number of sitting times was significantly decreased（P <0.05）.This indicates that high humidity（85%）at 23℃ significantly affected broiler resting behavior,respiratory rate,and skin temperature.In conclusion,moderate temperature has effects on behavior,physiology,biochemistry and molecular indices at different levels.From the perspective of growth performance and energy efficiency,temperature of 23℃ can be used as the beginning of moderate temperature.