Bioengineering of Cow Metabolic Rhythms Through Feeding Timing

The objective was to determine effects of feed presentation time and dietary forage to concentrate ratio on circadian and postprandial patterns of feed intake in lactating cows. Four multiparous and four primiparous Holstein cows were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. A higher or a lower concentrate Total Mixed Ration (TMR) was delivered at either 2100 h or 0900 h. The study consisted of four 21-d periods, each with 14-d of adaptation. A metabolic acquisition system was used to monitor continuous feed intake electronically. Feed presentation at 2100 h vs. 0900 h increased the amount of feed consumed within 3-h post-feeding from 26 to 37% of total daily intake. Dry Matter Intake (DMI) over the 24-h remained similar. Provision of TMR at 2100 h vs. 0900 h increased DMI in primiparous cows but not in multiparous cows. Results demonstrated that evening vs. morning feeding increased eating rate and feed intake shortly post-feeding. Timing of feeding, thus, could be a bioengineer and synchronizer of periprandial metabolic rhythms in lactating dairy cows.