Thyme (Thymus vulgaris) extract consumption darkens liver, lowers blood cholesterol, proportional liver and abdominal fat weights in broiler chickens

Abstract

A study with 160-day-old broiler chickens was conducted to investigate the effects of Thymus vulgaris (Thyme) extract in drinking water on plasma cholesterol, triglyceride, high density lipoprotein (HDL-c), low density lipoprotein (LDL-c) and very low density lipoprotein (VLDL-c), proportional abdominal fat, liver weights and liver color index. The chickens were divided into four groups and received 0 (ZT), 0.2 (LT), 0.4 (MT) or 0.6% (HT) thyme extract from day one to day 42 of age. All the birds receiving the Thyme extract had lower plasma total cholesterol, LDL-c concentrations and proportional liver weights compared with the control birds (P<0.05). Liver absolute weight of MT birds and proportional fat weight of HT birds were lower than those of ZT birds (P<0.05). Liver color index of HT and MT birds was higher than that of ZT birds. In orthogonal comparisons, thyme extract supplementation diminished (P<0.05) the plasma triglyceride, total cholesterol, LDL-c and VLDL-c, decreased the proportional and absolute liver weight and proportional abdominal fat weight and increased the (P<0.05) liver colour index as compared to control. Significant negative correlation (P<0.01) was found between the thyme extract supplementation and plasma cholesterol, proportional abdominal fat weight and liver proportional weight, and a positive correlation (P<0.01) between the thyme extract supplementation and liver colour index. In conclusion, Thyme consumption in broiler chickens could improve the carcass quality to the consumers and net returns of the producers.