Twenty four crossbred lambs (0.75 Rahmani X 0.25 Romanov) averaged four months old and 13.50 kg. live body weight were divided into four similar groups, six lambs/ group to compare the effect of  two feed additives (FA) based on medicinal herbs and plants on growth performance. Lambs were fed according to allowances of N.R.C. of sheep (1985) for seven months on a control ration (CR) free from FA, consisted of 25.36% concentrate feed mixture + 20.90% wheat straw + 53.74% berseem, on DM basis. Tested rations were composed per lamb/ day of : CR + 5 g. Biotonic (Biot.) for  tested ration 1 (TR1), CR + 5 g. Digeston (Dig.) for TR2 and CR + 5 g.: Biot. + Dig.  mixture (1:1) for TR3.  Results showed that TR1 significantly (P<0.05) improved all digestibility coefficients (DC) except EE and increased nutritive values (NV) as SV, TDN and DCP than those of CR that had the lowest values among treatments. Biotonic group significantly (P<0.05) raised DC of DM, OM, EE, CF than those of Dig. group, while  insignificantly improved DC of all nutrients and NV than those of TR3. Average final body weight (FBW) of TR1 lambs significantly (P<0.05) increased than those of the CR and TR2. Average daily weight gain (ADG) of TR1 was significantly (P<0.05) higher by 21.85 and 11.92% than those of CR and TR2, respectively. Biotonic group had insignificantly higher FBW and ADG values than those of TR3. Lambs consumed all tested rations exhibiting that FA didn't have any undesirable taste. Biotonic group showed the best feed conversion (FC) as kg. TDN, SV and DCP/ kg. BWG, while CR fulfilled the lowest FC/ kg. BWG followed by Dig. group. Biotonic group increased the economic return (ER)/head  by 21.71 and 20.23 % than CR and TR2, respectively, while CR  showed the lowest ER /h among treatments. This study recommends using Biotonic as feed additive to  elevate average daily weight gain and the economic return.