This study was carried out to investigate the effect of yeast culture combined with niacin or avoparcin on some blood parameters, supplemented to Akkaraman rams.

In the experiment, the sheep were divided into one control and two treatment groups each containing four Akkaraman male sheep. The experimental period covered 3 weeks of preliminary period and three basal feeding periods each containing of a month.

Blood total ketone, urea-N, blood serum total protein, total lipid, calcium, phosphorus, magnesium, copper, zinc, manganese values were not effected in the both groups consumed 4 g/day yeast culture (Thepax) plus 100 ppm niacin or 4 g/day yeast culture (Thepax) plus 15 ppm avoparcin in male sheep diets, however iron level increased (P<0.05) at the end of study.