Fifteen Rahmani ewes (38.9 ± 1.21 kg live body weight) belonging to the Agriculture Experimental and Research Station, Faculty of Agriculture, Cairo University were included in an experiment. The aim was to study the effect of inclusion of barley radicle (BR) as a partial substitution of the crude protein of the concentrate feed mixture at zero (control), 20 or 40 % levels on blood constituents, milk yield and composition. Changes in ewe weight and growth performance of lambs were also studied.  The experiment started 4 weeks before expected lambing date and continued through lactation till the weaning of born lambs at the 90^th day after lambing.                 Plasma urea and creatinine in mg %, total protein, albumin and globulin concentrations in g  % did not differ significantly among treatments.  Plasma GOT activity increased (P<0.01) with the 20% BR level compared to the other groups while GPT activity was almost similar for all treatments.  Heamatocrit  % did not differ significantly among treatments while hemoglobin % was decreased by 2.8 and 6.4 % relative to the control due to inclusion of 20 and 40 % BR in ewes diets.                 Daily milk yield increased by 12.3 and 21.6 % due to inclusion of BR at 20 and 40 %, respectively compared to the control ewes.  Milk total solids %, fat % and gross energy per kg milk tended to increase with the increase in BR level in ewe's diets.  Milk protein % was almost similar for the two BR groups with a tendency to be higher (7.8 %) than the control.  Milk lactose % decreased (P<0.01) with the high BR level.                  Lamb birth weight tended to increase non-significantly with the increased level of BR.  Average daily gain, weight gain till 90 days old and weaning weight of born lambs increased with the level of BR in ewe's diets but the increase was significant (P<0.05) with the high level only compared to the control.                 It could be concluded that barley radicle can be used up to 40 % of crude protein of the concentrate feed mixture in ewes rations to improve lactation performance and growth of born lambs with decreasing feed cost without any adverse effects in studied physiological functions.