Abstract

The effects of 0 (ZT), 0.2 (LT), 0.4 (MT) and 0.6% (HT) thyme extract in drinking water on the amounts of blood iron, hemoglobin (Hb), red blood cell (RBC), hematocrit (Hct) and total iron binding capacity (TIBC) on days 21 and 42 broilers were investigated. No significant differences were observed between the treatments for the amounts of blood Hb, RBC and Hct, but blood iron concentration of birds that received the thyme extract was lower as compared to that of control birds (ZT) on both ages (P<0.05). Blood iron concentration of LT and MT birds was lower than that of ZT birds and higher than that of HT birds (P<0.05) on days 21 and 42 of age. Blood TIBC of birds that received the thyme extract was higher (P<0.05) as compared to that of ZT birds on both determinations. HT birds had a higher blood TIBC amount (P<0.05) as compared to MT birds on day 42 of age. Negative and positive regression models (linear and quadratic) (P<0.0001) existed respectively between the thyme extract supplementation with the amounts of blood iron and TIBC on both ages. Inhibited iron absorption by thyme polyphenols or saponins is the possible reason.

Key words: Broiler chickens, thymus vulgaris, extract, iron, total iron binding capacity.