EFFECTS OF HEAT STRESS ON SOME PHYSIOLOGICAL INDICATORS TO THE BROILERS COBB

Four batches of Cobb broilers aged 14 days and average body weight of 480 g, grown in terms of age-appropriate diets were exposed to elevated ambient temperatures 38º-40ºC, varying by experimental scheme for a period of three weeks. Were determined weekly body weight, rectal temperature, hematocrit and hemoglobin and the results were compared with those obtained in the control group. Significant decreases in body weight of 7% in group 3 experimental starting in the second week. Rectal temperature increased on average by 5.5% in groups 2 and 3, but to group 4 the increase was insignificant. The largest decrease in hematocrit value was recorded in the 35 th day of the experiment and was 17.3% and 15.4% for groups 2 and 4. Also a significant decrease in hemoglobin was recorded in the 35th experimental day respectively 9.4% to 6.2% for groups 2 and 4. It has been found that the adaptation to the environment at higher temperature has been achieved by reducing the energy metabolism on the basis of the low food ingestion