LAUSR

ABSTRACT The effects of consumption of β2-agonist zilpaterol hydrochloride (ZH) were evaluated on hormonal blood metabolites (insulin, cortisol and thyroids), haemoglobin, haematocrit, plasma volume, heart rate and respiratory changes in male goats in the finishing phase. For this, 16 Mahabadi castrated male goats were used in a completely random design to evaluate the effects of treatments. Goats which were fed a finishing basal diet for 60 days prior to start the experiment were subsequently supplemented during 30 days with ZH at a dosage of 0.0 or with 20 mg ZH/kg LW. Haemoglobin concentration and haematocrit levels were recorded at 10-day intervals of experiment. Plasma volume was calculated using the haematocrit value. Heart and respiratory rates were recorded at 10-day intervals of experiment. Rates were recorded at 1-h intervals between 06:00 and 18:00 h. Hormonal profiles were measured at days 1 and 30. Plasma volume, heart and respiratory rates increased (P < .001) in the ZH group. Zilpaterol supplementation increased (P < .04) plasma insulin, and thyroids hormones, but decreased (P < .01) haemoglobin, haematocrit value and cortisol hormones. It can be concluded that zilpaterol supplementation of 0.20 mg ZH/kg LW significantly influences blood metabolic hormones concentrations, plasma volume, and cardiovascular and respiration rates.