The CFSI was associated with herd size, season at calving, and parity (P < 0.05). Cows that calved in the spring (mean ± SEM: 82.5 ± 0.49 days) and winter (82.7 ± 0.59 days) had longer CFSI than those that calved in the summer (76.6 ± 0.40 days) and autumn (78.2 ± 0.51 days; P < 0.05). In addition, the interaction between herd size and parity was associated with CFSI (P < 0.05; Table 2). For cows at parity 9 or higher, there was no difference in CFSI between herd size groups, whereas at parity 6 to 8, cows on large farms had shorter CFSI than cows on small farms (P < 0.05). On large farms, the mean CFSI in first-parity cows was shorter than that in parity 10 or higher (P < 0.05), but this difference in CFSI was not found on small farms.