Effects of Yeast Culture on Peripartum Intake and Milk Production of Primiparous and Multiparous Holstein Cows1

Multiparous (n = 40) and primiparous (n = 26) Holstein cows were fed a common TMR with top-dressed treatments of yeast culture supplementation at either 57 g/d (XP-2), 227 g/d (XP-8), or 0 g/d (control) from approximately 21 d prepartum to 21 d postpartum. Dry matter intake, lactation performance, metabolism, and feeding behavior were monitored. Prepartum DMI of XP-2 cows was greater by more than 1.4 kg/d compared with XP-8 cows (P < 0.01). Postpartum DMI and pre- and postpartum BW were similar for all groups. Milk yield was greater (P < 0.01) and 3.5% FCM (P = 0.09), energy-corrected milk (P = 0.10), and milk fat yield (P = 0.09) tended to be 10% greater for cows that were supplemented with yeast culture compared with nonsupplemented cows, and were not different for cows fed XP-2 compared with XP-8. Milk protein yield, milk protein percentage, milk fat percentage, and linear somatic cell score were not influenced by treatment. There were no significant effects of yeast culture supplementation on plasma BHBA, glucose, or nonesterified fatty acid concentrations pre- or postpartum. Yeast culture supplementation tended to increase the average number of prepartum meals per cow per day (P = 0.07), and XP-8 increased average daily meal duration (P = 0.05) and feeding time (P < 0.01) postpartum compared with XP-2. Yeast culture supplementation improved prepartum DMI and postpartum performance and improved the ability of cows to transition during the periparturient period. Primiparous and multiparous cows responded similarly when supplemented with yeast culture.