Under grazing conditions, daily intake can be estimated as the product of intake rate and grazing time but interactions with cow’s pre-grazing energy state may modify this relationship. A path analysis approach was used to explore relationships between ingestive behavior and cow’s pre-grazing metabolic variables affecting voluntary herbage intake of the first grazing bout in a morning session (VHI) in grazing dairy cows. Data of short-term ingestive behavior and pre-grazing metabolic variables was collected of 18 dairy cows (9 multiparous and 9 primiparous, days in milk = 73 ± 7; BW = 521 ± 32 kg BW; BCS = 2.75 ± 25; milk yield = 26 ± 3 kg) that grazed vegetative oat pasture (8 h of access to pasture from 8:30 to 16:30 h; pasture allowance = 30 kg DM/day; DM = 14%, CP = 23%, NDF = 46%, dry basis) and received supplementation after pm milking (6 kg DM/day of TMR of 70:30 forage to concentrate ratio, as-fed basis) from a short grazing experiment (20 d). Data were analyzed in SAS using the CALIS procedure. The direct and indirect relationships between bite rate (BR) and length of the first grazing bout (LFG, min), incisor arcade breadth (AB, cm) and pre-grazing serum glucose, insulin, glucagon, NEFA and BHB concentrations, with VHI (expressed as DM per 100 kg of metabolic weight) were estimated. The path analysis showed that direct effect of LFG was higher than AB (0.84 vs 0.34, P < 0.05), and BR did not correlate (0.026, P > 0.05) with VHI. In addition, pre-grazing NEFA and BHB concentrations correlates negative and positively to VHI (−0.56, P < 0.005; 0.71, P < 0.005), respectively, as indirect effects, and, pre-grazing NEFA and BHB concentrations correlates negative and positively (−0.74, P < 0.005; 0.71, P < 0.005), respectively, with LFG, as direct effects. The AB also correlates negatively to LFG but with lower standardized path correlation coefficient (−0.32, P < 0.05) than pre-grazing NEFA and BHB concentrations. Results predicted that the duration of the first grazing bout and pre-grazing NEFA and BHB concentrations are the main explanatory variables that affect the short-term herbage intake of dairy cows under temperate pastures.