Effects of Heat Stress on Some Physiological Indicators to the Broilers Cobb
Keywords:
Cobb broilers, haematocrit, haemoglobin, heat stressAbstract
Four groups 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. Weekly body weight, rectal temperature, haematocrit and haemoglobin were determined and the results compared with those obtained in the control group. Body weight recorded significant drops of 7% in group 3 starting from the first experimental week. Rectal temperature increased on average by 5.5% for groups 2 and 3 and for group 4 the increase was insignificant. In the dynamics of haematocrit there was a significant decrease of 7.2% in lot 3 in the first experimental week. Haemoglobin recorded in group 2, a significant decrease in the first two weeks averaged 5.8%, and 6.8% in group 3. It was found that the adaptation to the high temperature of the environment was achieved by the reduction of energy metabolism following low food ingestion and biochemical changes at the cellular level.
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