Ehsan Hosseini, Javad Cheraghi, Seyyed Saeed Taheri, Kamran Taherpour, Kianush Zarrin Kaviani and Leila Rezazadeh
Heat stress is one of the most severe complications in husbandry industry especially in poultry field. Hormonal turbulence in heat stress is among the side effects of this condition that harmfully influence broiler performance. The present study was designed to investigate thyroid hormones alteration under heat stress and probably effects of probiotic and prebiotic on this alterations. One hundred cab strain one day old broilers were randomly divided in 5 groups: control group under Normal Temperature (TN), Treatment group treated with heat stress (HS), group HSBIOMOS (administered with BIOMOS prebiotic under heat stress), group BIOSAF-HS (administered with BIOSAF probiotic under heat stress) and group HS-CMB (administered with combined BIOMOS –BIOSAF probiotics under heat stress). Duration of this experiment period was 42 days. In days 21, 35 and 42 blood samples were collected via wing vein and after serum preparation, the samples was maintained in deep freez (under 18 0C ).Thyroid hormones(T3 and T4) measurement was done by Eliza Kits (Stat Fax automated apparatus). The results showed that heat stress is significantly(p≤0.05) effective in lowering the T3 and T4 hormones in comparison to control group but consumption of prebiotic and probiotic is positively and statistically (p≤0.05) effective in normalize the thyroid hormones .