The objective of this study was to evaluate if the concentration or the amount of Ca excreted in colostrum harvested at first and second milking was associated with postpartum serum Ca concentration on multiparous Jersey cows. Colostrum samples and weights were collected at first (n = 134) and second (n = 68) milking at 9 h 36 min (±3 h 36 min) and 21 h 21 min (±3 h 14 min) relative to calving, respectively. Colostrum samples from first and second milkings were analyzed for Ca concentration (CCa_c). Blood samples for serum Ca concentration analyses were collected from coccygeal vessels within 6 h after calving before first milking (SCa₁), and 43 min (±28min) after second milking (SCa₂). Total Ca excreted in colostrum (CCa_g) was calculated as CCa_c × colostrum weight. The CORR procedure of SAS was used to evaluate the association among SCa₁, SCa_2, CCa_c and CCa_g. To study explanatory variables of SCa₂ a linear regression model with repeated measurements was fitted using the MIXED procedure of SAS including CCa_c, milking time, and colostrum weight. There was not an association between SCa₁ and SCa₂ (r = 0.23; P = 0.06), CCa_c1 (r = 0.09; P = 0.45), or CCa_g1 (r = −0.05; P = 0.53); nevertheless, SCa₂ was associated with CCa_c2 (r = −0.32; P = 0.007), but not with CCa_g2 (r = 0.02; P = 0.85). At second milking, we observed a decrease in SCa_c2 as CCa_c increased. No effect of colostrum weight was detected on SCa₂. Our results indicate that postpartum calcemic status might be affected by concentration of Ca in colostrum.