This study was conducted to evaluate the effect of dietary supplementation of protected fatty acids (FA) on nutrient digestibility, rumen parameters, some blood components, milk yield and its composition and lambs growth performance during the pre-weaning period (2 months old) of Suffolk x Ossimi ewes. A total of 36 pregnant ewes, weighing on the average 64.89±1.57 kg in their 2^nd – 4^th parities and aged 2.5 – 4.5 years were divided into three similar groups according to their body weight (12 ewes each) using a complete randomized block design .The feeding trial started 60 days before lambing (late pregnancy period) and continued 60 days after lambing (suckling period). The experimental rations were offered into animals with the rate of 0, 4 and 6% calcium-soap as protected fatty acids (based on DM intake). Body weight, total gain and daily gain of the new born lambs were recorded during the preweaning period (suckling period). The basal rations composed of 60% concentrate feed mixture (CFM) and 40% roughage (berseem 30% + rice straw 10%, RS).Three digestibility trials were carried out using nine Suffolk x Ossimi crossbred rams with average 62 kg BW and aged 2-2.5 years to determine the digestibility and feeding values of the experimental rations. Data showed that significant higher digestibility at (P <0.05) of OM, CP, CF, EE and NFE for fat supplemented groups than those of control one. Rumen parameters (pH, total VFAs and ammonia-N concentration) were higher in supplemented groups than those of the control one. Values of concentrations of blood plasma total protein and its fractions, glucose, total cholesterol, triglycerides and total lipids of experimental ewes were higher in for supplemented groups than that of control one in the two stages of the whole production cycle. Supplemented fat treatments (group) led to significant increases in birth, weaning weights and total gain of lambs, and the highest values were occurred with FA₆. Milk yield was higher significantly in supplemented groups than that of control one as well as its composition (fat, total solids and protein, %) were followed the same trend of milk yield among treatments. Generally, it could be concluded that the supplementation of calcium salt of fatty acids at different levels (FA₄ or FA₆) for rations of Suffolk x Ossimi crossbred ewes improved digestibility, feeding values, increased lambs birth weight and milk yield and its composition beside better feed efficiency, with  superiority  of 6% level (FA₆).