This study was conducted to evaluate the effect of daily oral administration of Friesian dairy heifers with propylene glycol (PG); calcium propionate (CP) or their combination (PG+CP) from about 15 months of age till the occurrence of conception on blood biochemistry and body weight. Heifers in the 1^st group were fed on the control ration (T1), while those in G2, G3 and G4 were fed the control ration with 300 PG, 335 CP, and a combination of 150 PG+165 CP ml/head/twice a week, respectively from the initial of experimental work to conception. Results show that, the total proteins, albumin, globulin and glucose were significantly increased (P<0.05) in T4. At puberty and conception periods T4 showed significant (P<0.05) increase in TP, AL, GL, and Glu as compared to T1. Blood total lipids and triglycerides showed significant decrease (P<0.05) in T4 at puberty and conception periods. The total cholesterol concentration was significantly decreased (P<0.05) in T2-T4 as compared to T1. Urea nitrogen concentration in T4 was the lowest value followed by T3 and T2 as compared with T1 at puberty and conception periods. Heifers in T4 and T3 showed decrease (P<0.05) in creatinine concentration at puberty and conception than those in T1 and T2. Liver enzymes (AST and ALT) were lower (P<0.05) in T4 at puberty and conception than the control group. Blood AST and ALT were moderated in T2 and T3 at puberty and conception periods. At puberty, heifers in T4 showed the heavy LBW (P<0.05) followed by T3 then T2 and T1. At conception the higher LBW (P<0.05) was recorded in T2-T4 as compared with T1. Heifers in T4 had the early time (P<0.05) to shown puberty followed by T3 and T2 compared to T1. Also, heifers in T4 were concept at early time (P<0.05) than T1. In conclusion, feeding Friesian female calves on diet supplemented with 150ml propylene glycol plus 165 ml calcium propionate /head/twice a week can improve blood biochemical at puberty and conception periods with increase heifers live body weight and it achieved early time to puberty and conception.