Clinicopathological Studies on Broiler Exposed to High Environmental Temperature

The present study was performed to investigate theclinicopathological changes associated with acute and chronic heatexposure in chickens. One hundred one day old Hubbard chickswere used for this experiment. They divided into five equal groups.The first gp. kept as negative control (non treated non heatstressed), gp. (2) were exposed to 42±l QC for 3 hrs. with RH. 45-60% at 45 days old, gp. (3) were treated with Anti heat stresslgmIliter water orally 24hrs. before heat exposure and exposed to42±1 QC for 3hrs with RH. 45-60%. at 45 days old, gp. (4) wereexposed to 39±1 QC for 6 hrs. for 3 successive days with RH. 45-60%. at 43, 44 and45 days old while gp. (5) were treated with Antiheat stressl gmlliter water orally 24hrs. before heat exposure andexposed to 39±1 QC for 6 hrs. for 3 successive days with RH. 45-60%. at 43, 44 and 45 days old.Clinical signs was observed. Blood and serum samples werecollected at the same time (0, 12 and 36 hrs. after heat exposure) forhematological and clinicobiochemical studies. Tissue specimenfrom liver, kidneys, lung and heart from all gps. were examinedmacroscopically and microscopically.Chickens exposed to acute and chronic heat exposure (gps. 2and 4) were standing with wings outstretching, off food, panting(open mouth breathing) and laying on the ground during periods ofexposure with mortality rate reached 20% in acute exposure. Gps.(3 and 5) exposed to acute and chronic heat exposure and treatedwith no-heat stress) showed some improvement in the clinical signs.