Effects Of Roofing Sprinkle Cooling System On Open Beef Cattle Barn In Soruthern China

In order to relieve the summer heat of Southern heat stress on production performance of beef cattle and investigate the effects of different environmental regulation forms.24 Jin jiang beet cattle were divided into 3 groups,each group was eight cattle.Environmental regulation forms of Group 1,Group 2 and was Groups 3 were interior ventilation,interior spray ventilation and roofing sprinkle ventilation.Environment temperature,humidity temperature of rectal,breathing rate,daily weight gain and other relevant indicators were measured.Environment temperature,humidity temperature of rectal,breathing rate,daily weight gain and other relevant indicators were measured.In order to study mechanism relieving heat stress with roof sprinkling ventilation and cooling system.Blood biochemical indices,immune index and inorganic ion of beef cattle were measured.The results showed that:1 Effects of interior spray ventilation and roofing sprinkle ventilation cooling on open beef cattle barn in Southern ChinaDuring running time(between10:00 to 18:00)for the roofing sprinkle ventilation,compared with Group 1,temperature of 0、1、2 and 3 m under the roof for Group 3decreased 4.79 ℃(P<0.01)、 2.13 ℃(P<0.01),1.37 ℃and 1.42 ℃,respectively.The humidity increased 9.66 %(P<0.01),6.76 %(P<0.01),2.66 %and 1.80 %;respectively.At14:00,temperature of 1.5m and 0.5m apart from ground decreased 1.2 ℃(P<0.05)and1.07 ℃.The breathing rate decreased 12 times/min(P<0.05).The rectal temperature had no significantly change.Daily weight gain increased 0.19 kg/d,the rate of improvement was 26.38 %(P<0.05).At 14:00 during the spray running time,compared with Group 1,the effective temperature before and after the spray of Group 2 decreased 0.51 ℃and1.43℃(P<0.05).The rectal temperature at 18:00 decreased 0.70 ℃and 1.60 ℃(P<0.05).The breathing rate decreased 13 times/min(P<0.01).The rectal temperature had no significantly change.Daily weight gain increased 0.08 kg/d,the rate of improvement was11.11%.2 Effect of Roof Sprinkling Ventilation and Cooling System on Blood Biochemical Indices of Beef Cattle in Heat StressCompared with these at 1 day,T3 content of Group 1 at 15 day and 30 day reduced by5.68% and 8.52%.While that of Group 3 at 15 day and 30 day increased 1.65% and 5.49%.T4 content of Group 1 was no significant difference at 15 and 31 day.While that of Group2 at 31 day improved 14.48%(P<0.05).COR content of Group 1 was not significant difference,but had a rising trend.COR content of Group 3 had a downward trend(P<0.01).IGF-I content of Group 1 at 31 day decreased 4.93%.While that of Group 3 increased 9.98%.GLU content of Group 1 at 15 day and 31 day increased 2.30% and 5.75%,respectively.Meanwhile that of Group 3 improved 6.63% and 19.83%.TP,ALB and GLO content of Group 1 declined at 15 day and 30 day.While that of Group 3 increased.Ig M content of Group 1 decreased.While Ig M content of Group 3 increased significantly.Inorganic ions content of Group 1 declined.Inorganic ions content of Group 3 had rising trend.But the difference was not significant.These results suggested that roofing sprinkle ventilation can relief the heat stress of beef cattle in some way,the metabolic disorder can be effectively improved and diseased resistance of beef cattle can rise with roof sprinkling ventilation and cooling system under high temperature and high humidity climate in summer in the south.