Changes in Plasma Thyroids Hormones, Heart Hypertrophy, Mortality and some Blood Parameters in Broilers with Pulmonary Hypertension Syndrome (PHS)

A study with 160 one-day age male broilers (Ross 308) was for six week period، conducted to investigate the some blood parameters، and plasma thyroxin (T4) and triiodothyronine (T3) of broiler chickens with cold induced pulmonary hypertension syndrome (PHS). Chicks in 2 groups of 4 replicates were studied in each group20 chicks for each replicate were used. One group set as control (healthy) group and reared under normal temperature، second group set as PHS group and reared under cold temperature. At the end of the experiment (day 42)، 2 chicks from each replicate were randomly selected bled and slaughtered. The heart was removed and the right ventricle was dissected away. The ratio of right ventricle weight to total ventricle weight (RV/TV) was calculated. The results showed that hematocrit value، mortality due to ascites، RV/TV index and differential white blood cells count were significantly higher in CT treatment chick (P<0. 05). The concentrations of plasma t4 of CT birds were significantly lower than other group birds at day 21 & 42. it is also، The concentrations of plasma t3 of CT birds were significantly higher than other group birds at day 21 (exception day 42) (P<0. 05).