Twelve lactating Friesian cows with an average body weight of 490-560 kg in the second to fourth lactation seasons were randomly distributed into three similar groups (four for each group). All groups were individually fed according to NRC (2001) recommendations. The three experimental rations were formulated as follows: (Control): 40 % concentrate feed mixture (CFM) + 32 % rice straw (RS) + 28 % corn silage (S), (T1): 40 %  (CFM) + 32 %  (RS) + 28 % berseem (B) and (T2): 40 % (CFM) + 32 % (RS) + 14 % (S) + 14 % (B). Three digestibility trials were conducted to determine nutrients digestibility coefficients and nutritive values of the experimental rations. Each digestibility trial consisted of 15 days preliminary period followed by 7 days collected period. Results showed that the digestibility coefficients of OM was significantly (p<0.05) higher with feeding on T2 than feeding on T1, but without significant difference with feeding control ration. The NFE digestibility was significantly (p<0.05) higher in T2 compared with the control or T1. The nutritive values expressed as TDN, ME, NE and RFV were significantly (p<0.05) higher with feeding on the control and T2 than feeding on T1. The mean value of rumen pH was decreased (p<0.05) when feeding the control ration compared with T1 (6.73 and 7.15, respectively). The same trend was observed on ruminal eNDF%. There were no significant effects among the treatments, regarding ruminal VFAs and NH3 concentrations.  There were no significant effects of treatments on microbial count of fibrolytic or amylolytic bacteria, but feeding control or T2 rations were increased the microbial count mainly  fibrolytic bacteria in the rumen than feeding on T1. Feeding on T1 ration increased amylolytic bacteria than feeding on the control or T2. There were significant effects on blood lipten, insulin, free fatty acids and triglycerides concentrations. The concentrations were higher (p<0.05) when feeding on T1 than feeding on control and T2 or when feeding on T2 than feeding on the control ration. The NEFA and urea concentrations were higher when feeding on T1 than feeding on the control ration but there were no significant effects when feeding on T1and T2 or between the control and T2. The results showed that there were no significant effects on glucose, cholesterol and total protein concentrations when animals were fed the experimental rations. So, feeding on the T2 showed appropriate similar results as that obtained with the control ration in terms of nutrient digestibility, feeding values, rumen parameters and blood parameters.