Supplementing in the diet of lactating Holstein cows may naturally produce coenzyme Q10-enriched milk.

Objective: To examine the effects of () supplementation as a direct-fed microbial (DFM) on rumen fermentation in dairy cows and on coenzyme Q10 (CoQ10) transition into milk, an rumen simulation batch culture and an dairy cow experiment were conducted.

Methods: The characteristics of ruminal fermentation were investigated using rumen fluids from six cannulated Holstein dairy cows at 2 h post-afternoon feeding. A control treatment was included in the experiments based on a typified total mixed ration (TMR) for lactating dairy cows, which was identical to the one used in the study, plus at 0.1%, 0.3%, and 0.5% TMR dry matter. The study employed six ruminally cannulated lactating Holstein cows randomly allotted to either the control TMR (C-TMR) treatment or to a diet supplemented with a 0.5% culture (S-TMR, dry matter basis) . The presence of was verified using denaturing gradient gel electrophoresis (DGGE) applied to the bacterial samples obtained from the study. The concentration of CoQ10 in milk and in the supernatant from the study was determined using high performance liquid chromatography.

Results: The results of the batch culture and DGGE showed that the concentration of CoQ10 significantly increased after 2 h of supplementation above 0.1%. When supplemented to the diet of lactating cows at the level of 0.5%, did not present any adverse effect on dry matter intake and milk yield. However, the concentration of CoQ10 in milk dramatically increased, with treated cows producing 70.9% more CoQ10 than control cows.

Conclusion: The CoQ10 concentration in milk increased via the use of a novel DFM, and might be used for producing value-added milk and dairy products in the future.