Effects Of Water-misting Sprays With Forced Ventilation After Transport During Summer On Meat Quality And Postmortem Muscle Energy Metabolism In Broilers

Under the condition of modern intensive production,chicken before turn in and out of the farms,group,centralized slaughtering all need to transport,transport process will inevitably occur stress,and strong stress can seriously affect the physiological and metabolic function of broilers,so that it would cause decrease the quality muscle or even cause disease,death,which cause losses for the poultry industry.In recent years,our country has become the second largest poultry producer which was only second to American;the losses caused by transport stress could not be ignored.However,the research how to ease stress caused by transport during summer and improve the meat quality is rare in country and mang broiers processing industries do not attach great importance to it.This study made a thorough inquiry of the effect of water-misting sprays with forced ventilation on chicken PSE(pale,soft,exdudative)meat by studying the effect of water-misting sprays forced ventilation on microenviroment;in addition,we had a research on the effect of water-misting sprays with forced ventilation after transport during summer on stress and postmortem muscle metabolism in broilers in order to know the essence of improve the meat quality by water-misting sprays with forced ventilation;in that way,it can provide data and reference for broiler processing industries.1.An evaluation of the effect of water-misting sprays with forced ventilation on the occurrence of PSE meat in transported broilers during summer:impact of the thermal microclimateThis study investigated the effects of water-misting sprays with forced ventilation on the occurrence of PSE meat in transported broilers during summer combined with the evaluation of the thermal microclimate.In order to evaluate the thermal microclimate within trucks,temperature(Te),ventilation(VT)and relative humidity(RH)were tracked at different locations using 18 data loggers.Three hundred broilers per load of 2,500 were monitored individually.Three transport test runs were divided into three treatment groups:1)45-min transport without rest(T),2)45-min transport with 1-h rest(TR),3)45-min transport with 15-min water-misting sprays with forced ventilation and 45-min rest(TWFR).Birds were slaughtered in a commercial facility and meat quality of the chilled carcasses was evaluated by determination of pH,color,drip loss,cook loss of the pectoralis major muscle.The temperature(Te)and enthalpy(H)of the T group at different regions in the vehicle were significantly(P<0.05)different.The temperature(Te)and enthalpy(H)of the T group at different regions in the vehicle were significantly(P<0.05)different.Compared with PM meat from the T group at different regions of the vehicle,meat from the TWFR group at different regions of the vehicle was significantly(P<0.05)different for pH,meat color lightness(L~*-value)and cook loss.Meat from the TWFR group at different regions of the vehicle was not significantly(P>0.05)different for pH,meat color lightness(L~*-value),redness(a~*-value),yellowness(b~*-value)or drip loss.The results showed that broilers located at the rear of the vehicle experienced severe conditions of Te,VT and RH,which resulted in the worst meat quality and the highest incidence of PSE meat.However,application of water-misting sprays with forced ventilation immediately after transport eliminated the effect of different microclimatic regions at different positions and created a relatively comfortable environment that may alleviate stress.Moreover,the water-misting sprays with forced ventilation after transport improved the meat quality and reduced the incidence of PSE meat.Although rest after transport also improved meat quality,the effect was not as significant as water-misting sprays with forced ventilation.2.Effects of water-misting sprays with forced ventilation after transport during summer on meat quality,stress parameters and microstructures of muscle in broilersEffects of water-misting sprays with forced ventilation after transport during summer on meat quality,stress parameters,glycolytic potential and microstructures of muscle in broilers were investigated.A total of 63 mixed-sex Arbor Acres broilers were divided into three treatment groups:1)45-min transport without rest(T),2)45-min transport with 1-h rest(TR),3)45-min transport with 15-min water-misting sprays with forced ventilation and 45-min rest(TWFR).Each treatment consisted of three replicates with seven birds each.The results showed the TWFR group significantly increased(P<0.05)initial muscle pH(pHi),ultimate pH(pHu),the expression of Hsp70 and significantly reduced(P<0.05)L~*,drip loss,cook loss,creatine kinase(CK),lactate dehydrogenase(LDH)activity,plasma glucose content,lactate and CORT when compared with other groups.Microstructure of the muscle from TWFR group broilers under light microscopy showed smaller intercellular spaces among muscle fibers and bundles compared with T group.In conclusion this study indicated water-misting sprays with forced ventilation after transport could relieve the stress caused by transport under high temperature,which was favorable for the broilers’welfare.Furthermore,water-misting sprays with forced ventilation after transport slowed down postmortem glycolysis rate and inhibited the occurrence of PSE-like meat in broilers.Although rest after transport could also improve the meat quality,the effect was not as significant as water-misting sprays with forced ventilation after transport.3.Effects of water-misting sprays with forced ventilation after transport during summer on postmortem muscle metabolism in broilersEffects of water-misting sprays with forced ventilation on postmortem glycolysis,AMP-activated protein kinase(AMPK)and meat quality of broilers after transport during summer were investigated in the present paper.A total of 63 mixed-sex Arbor Acres broilers were divided into three treatment groups:1)45 min transport without rest(T),2)45 min transport with 1 h rest(TR),3)45 min transport with 15 min water-misting sprays with forced ventilation and 45 min rest(TWFR).Each treatment consisted of three replicates with seven birds each.The results indicated that the water-misting sprays with forced ventilation could mitigate the stress caused by transport under high temperature conditions during summer,which reduced the energy depletion in postmortem pectoralis major(PM)muscle.This resulted in a higher energy status compared to the T group,which would decrease the expression of phosphorylation of AMPK(p-AMPK).Furthermore,decreased the expression of p-AMPK then slowed down the rate of glycolysis in postmortem PM muscle during the early postmortem period,which in turn lessened the negative effects caused by transport on meat quality.In conclusion,water-misting sprays with forced ventilation may be a better method to control the incidence of the PSE meat in broilers.