The object of this study was to evaluate the effect of supplementing propylene glycol (PG) and calcium propionate (Ca-pr) as energy source on performance, ruminal fermentation, and some metabolic parameters of fifteen Egyptian buffalo male calves average body weight (LBW) 212.27 ±8.684 kg divided into three similar groups (5/each) based on LBW, the
experimental animal in the 1st group control drenched at 3 liters of saline solution (Nacl 0.9%) without addition, while, the 2nd group (PG) drenched 300mL of propylene glycol dissolved in 3 liters of (Nacl 0.9%) and the 3rd group (Ca-pr) drenched with 335g of calcium propionate dissolved in 3 liters of (Nacl 0.9%). Calves administered through esophagus via esophagus feeder tube twice/weekly for 6 months experimental period. Statistical analysis revealed that the administration of Ca-pr and PG increased (P<0.05) total gain and average daily gain while, DM and TDN feed conversion decreased (P<0.05). Moreover, feed intake remained un-affected among treatments. Ruminal pH and calculated eNDF values lower (P<0.05) in Ca-pr drenched calves' than PG and control treatments. On the contrary, total VFA's, NH3-N concentrations, buffering capacity values and ruminal molar proportion of propionate and butyrate tended to be greater in Ca-pr group than animals receiving other treatments however, acetatedidn't affectbytreatments. Ca-pr and PG groups decreased (P<0.05) in NEFAplasma and ß-hydroxybutyrate levels while, plasma glucose, serum insulin concentration and glucose to insulin ratio were more significantly (P<0.05) than control group during the experimental period. In brief Ca-pr and PG additives had beneficial impact on performance and some metabolic parameters buffalo male calves so; it could be used partially as energy supply in their diets.