Effects of prepartum dry matter intake and forage percentage on postpartumperformance of lactating dairy cows

The objective of this research was to determine whether different dry matte r intakes (DMI) or forage percentages prepartum would have an impact on pos tpartum performance. Multiparous Holstein cows (n = 41) received either hig h (H) or low (L) forage rations that were fed free choice (F) or restricted (R), i.e., HF, HR, LF, and LR. The L rations were higher in net energy of lactation and lower in neutral detergent fiber concentrations. After calvin g, all cows were fed the same ration ad libitum. Prepartum DMI were 8.0 for R versus 12.4 kg/d for F with LF greater than HF (14.1 vs. 10.7 kg/d). Pre partum treatments did not affect postpartum means for DMI, milk yield, milk protein percentage, body weight, body condition score, or plasma glucose c oncentrations (overall means 1 to 40 DIM were, respectively, 21.1 kg/d, 34. 0 kg/d, 3.03%, 624 kg, 3.2, and 66 mg/dl). However, curves from 1 to 40 DIM showed that DMI and milk yield were slightly higher in early lactation in cows whose DMI had been restricted prepartum. but mean milk fat percentage was lower (3.10 vs. 3.42%). Plasma NEFA were higher and insulin lower in H versus L before and after calving. High DMI prepartum, at best, showed no a dvantage over restricted feeding.