The effect of rearing strategy on the dry matter intake of pasture-based dairy heifers

Although dry matter intake (DMI) is important in terms of achieving heifer weight-for-age targets and the utilization of pasture, the DMI of pasture-based heifers has not been widely researched. In order to quantify pasture-based heifer DMI and to determine the effect of different rearing strategies on DMI, data were collected from Holstein-Friesian (HF; n = 124), and Jersey (JE; n = 56) heifers weaned at either eight or 12 weeks and subsequently offered either a low or high post-weaning feeding regime. The n-alkane technique was used to measure the DMI of the heifers on nine occasions throughout the rearing period. Nutrition and management in the post-weaning period had a greater effect on DMI than that of weaning age. Although HF heifers had a higher total DMI than JE, JE heifers had a higher DMI when expressed as a percentage of BW. The results from this study indicate that rearing strategy may be used to manipulate DMI, and thus optimize the attainment of weight-for-age targets in pasture-based heifers.