The aim of this study was to compare the use of exogenous enzyme preparations (EZ) and/or Salix babylonica extract (SB) or their combination as feed additives on some haematological parameters in growing lambs. Twenty Suffolk lambs of 6 to 8-months-old with 24±0.3 kg body weight were used in the study. Lambs were divided into 4 groups of 5 animals each in a completely randomized design and the treatments were: 1.control: fed a basal diet of concentrate (30%) and maize silage (70%); 2. EZ: fed the basal diet plus 10 g of enzyme; 3. SB: fed the basal diet plus 30 ml of S. babylonica extract, and 4. EZSB: fed the basal diet plus 10 g enzyme and 30 ml of S. babylonica extract. Lambs were housed in individual cages and the experiment was conducted for 60 days. The SB was given orally while the EZ was mixed with a small amount of the concentrate and maize silage and was offered ad libitum. Blood samples were collected from each animal on days 0, 15, 30, 45 and 60 of experiment and analysed for haematological parameters. The treatments of EZ, SB or EZSB did not affect any of the measured blood parameters. Day of sampling modified concentrations of red blood cells (P=0.001; linear effect), haematocrit (P=0.01; quadratic effect), haemoglobin (P=0.01; linear effect), mean corpuscular volume (P=0.01; linear effect), monocytes (P=0.004; quadratic effect) and plasma protein (P=0.0002; linear effect). It could be concluded that Salix babylonica extract, exogenous enzymes and their combination as feed additives had not a negative effects on the blood parameters measured and therefore on the health of the lambs
