Feed efficiency is an economically important trait in the dairy industry as feed costs account for a large proportion of cost of production. Unfortunately, technologies to measure feed intake are cost prohibitive for use on commercial dairies. Thus, identification of portable technologies that collect measurements as indicators of feed intake or efficiency could be of great value to the industry. The objective of the current study was to explore the use of automated rumen sensor data as possible indicators of feed intake in lactating dairy cattle between 40 and 80 DIM. Wireless ruminal monitors (smaXtec Animal Care. Wastiangasse, Austria) were used to collect pH and temperature every 10 min on 17 cows. pH probes were delivered by mouth on the first day of lactation and began automated data collection at that point. Daily feed intake and weekly body weights were also recorded. Data were filtered in an attempt to remove faulty readings based on constant decline in pH readings overtime (drift), resulting in a total of 14 cows remaining in the data set. Hourly mean pH and temperature values were calculated for 40 to 80 DIM on each cow. Data were analyzed using PROC MIXED in SAS where feed intake was modeled including fixed effects for rumen pH or temperature, and metabolic body weight (MBW) as well as random effects of animal and time. The MBW was calculated as body weight taken to the 0.75 power (BW^0.75). Rumen temperature was significantly associated with feed intake (P < 0.016), while there was a slight tendency for an association of rumen pH (P < 0.13). In both models, MBW was significantly associated with feed intake (P < 0.0001). Further analyses are warranted to determine the relationship of these rumen traits to milk production and composition, and other measures of efficiency. Additional studies are merited to validate these findings to determine if either of these novel traits could be a suitable indicators of feed efficiency.