Effect of parity number on the dry matter intake of dairy cows during the first week after calving.

We investigated the effect of parity number on the dry matter intake (DMI) of cows during the first week after calving. Eighty-three cows were evaluated from 14 days before to 7 days after calving. DMI and milk yield were measured for 7 days after calving, and the calving score was measured. Blood samples were collected throughout the experiment. The average DMI during the first week after calving was reduced in the first-lactation heifers and high-parity number cows. A quadratic relationship between the parity number and the DMI was observed. The first-lactation heifers had lower prepartum serum total protein (TP) concentration and milk yield, higher prepartum serum nonesterified fatty acid (NEFA) concentration and calving score than the multiparous cows. The recovery rate of serum calcium (Ca) after calving was slow in the cows in the parity 6. The DMI was positively affected by the serum Ca concentration after calving, milk yield, and prepartum serum TP concentration and was negatively affected by the calving score and prepartum serum NEFA concentration. We conclude that the DMI immediately after calving tends to be lower in first-lactation heifers and high-parity number cows, but factors that reduce the DMI differ according to parity number.