Rumen lipopolysaccharide activity is suppressed by bovine lactoferrin feeding in dairy cows during dry and lactation periods

We investigated the effect of bovine lactoferrin (LF) feeding on reticulum pH, rumen lipopolysaccharide (LPS) activity, nutritional metabolism, and milking performance in Holstein cows during dry and lactation periods. We randomly assigned 24 Holstein cows to two groups : the LF (10g/day) feeding group (n＝12) and the no additive (control) group (n＝12). During dry periods, cows received 120% of their total digestible nutrient requirement. During lactation periods, cows received a completely total mixed ration with 33% neutral detergent fiber comprising timothy hay (30%) and a commercial concentrate (70%). Seventeen cows (10 in the LF feeding group and seven in in the control group) were selected for reticulum pH measurement using a radio transmission pH sensing system developed for research, which collected pH data at 10-min intervals during the testing period. The number of hours during which reticulum pH was below 6.1 increased in all cows, regardless of LF feeding, after parturition. In addition, eight cows in the LF feeding group and four cows in the control group were found to have subacute ruminal acidosis (SARA). However, there was no significant difference in the SARA incidence rate between groups, and LF feeding was considered to not affect SARA occurrence. Rumen LPS activity was lower (P