PSV-3 - Changes in Sow Farrowing Performance with Parity

Abstract: Sow culling decisions are based, in part, on changes in productivity with increasing age. However, there is limited published information from detailed evaluation of changes in performance with parity in contemporary commercial sows. The objective of this study was to re-evaluate relationships between sow parity and productivity measures. Data (1005 sows/litters, 12857 piglets) were from 5 controlled studies conducted on the same commercial farrowing facility using the same management. Sow parity (average 5.0 ± 2.79) ranged from 1 (gilts) to 14. Measurements included farrowing duration (sub-sample of 289 litters), number of piglets born alive, average and within-litter CV of piglet birth weight (BW), and sow rectal temperature at the start and end of farrowing. Data were analyzed using PROC MIXED of SAS. Models accounted for the random effect of study and the fixed effect of sow parity category (1, 2, 3 to 4, 5 to 7, and ≥ 8). Farrowing duration was similar (P > 0.05) across parity categories (Table 1). Litter size was greater (P ≤ 0.05) for parities 5 to 7 compared to parities 1 and 3 to 4, with parities 2 and ≥ 8 being intermediate and similar (P > 0.05) to all other categories. Average piglet BW was lowest (P ≤ 0.05) for parity 1 and greatest (P ≤ 0.05) for parity 2 and 3 to 4 sows. The CV of piglet BW generally increased (P ≤ 0.05) with parity. Rectal temperatures at the start and end of farrowing were generally greater (P ≤ 0.05) for parity 1 and 2 sows compared to the other parity categories, which were similar (P > 0.05). In conclusion, these results suggest that changes in performance with parity were relatively limited and that sows with parities that are typically considered high have relatively similar performance to those of lower parity.