Twenty-seven Saidi lambs (8W, 20.37 + 0.75; age 8 mo) were randomly assigned to three treatment groups: a control group (C) receiving no Kl supplement, and two supplemented groups (L) and (H) receiving 40 and 80 mg Kl/head/wk, respectively. All groups were fed a concent rate pelleted diet ad libitum during the 84-d experimental period. Blood samples were collected from all lambs twice a day (0900 h and 1600 h) at days 29,57 and 82 of the experiment. Treatment did not affect (P 0.10) feed intake, average daily gain (ADG) or feed efficiency of lambs. However, feed intake tended to decrease with increasing Kl level and ADG tended to be higher in L than C lambs, whereas H lambs gained the lowest over the whole experimental period. Treatment did not affect (p 0.10) erythrocyte counts, hemo globin (Hb) concentration or packed cell volume (PCV). Erythrocyte counts and PCV were higher at 0900 than 1600 h. Total number of leukocytes was lower (P 0.10) only at d 29 of the trial in H lambs than either C or L lambs. Serum total protein, albumin and globulin tended to be higher, whereas cholesterol tended to be lower in H lambs than Cor Llambs, but differences were not significant (P 0.10). Body temperture, respiratory and pulse rates did not differ among treatments.