Dam parity of origin is associated with lifetime productivity in first parity sows

Sow lifetime productivity is a key driver of productivity and sustainability in pig production systems. While primiparous sow progeny differs from those born to multiparous sows during early growth, less is known about whether dam parity (DP) of origin influences lifetime productivity once females enter the breeding herd. The objective of this study was to evaluate associations between DP and lifetime growth, reproductive performance, and longevity in replacement gilts born from different parity groups. Production records from 7,662 purebred Large White females entering 11 European multiplier herds during a 5-year were analyzed. Data included females' DP (i.e. DP1, DP2 and DP3+), litter of origin total born (TB) and born alive (BA) piglets, lifetime daily weight gain (LDWG) until end of the testing period, age at first service, age at first successful service, age at first farrowing, TB, BA, and wean-to-service interval (WSI) from parity 1 to 6, parity at removal, removal type (i.e. dead vs culled) and removal reasons. Sows were matched in a 1:1:1 ratio, with one female per dam parity group, based on litter of origin characteristics. Differences in early-life indicators and reproductive traits across parities were evaluated using mixed models. Longevity was assessed using survival and competing risks models, partitioning removals into mortality and culling and further by cause. DP1 sows exhibited lower LDWG and reached key reproductive milestones later, being on average 6 days older at first mating, first successful mating, and first farrowing compared with females born to DP2 and DP3+ sows (P < 0.001). During early parities, DP1 females produced fewer TB and BA piglets, translating into 0.3 to 0.5 fewer piglets per litter, respectively during their lifetime compared with females born to DP2 and DP3+ sows. Overall removal risk was greater for DP1 sows (P < 0.001). Differences in removal were driven primarily by greater culling for reproductive failure (DP1 vs DP2: Sub-distribution hazard ratio (SHR)=0.84; P = 0.007; DP1 vs DP3+: SHR=0.72; P < 0.001) and unknown causes (DP1 vs DP2: SHR=0.82; P < 0.001; DP1 vs DP3+: SHR=0.57; P < 0.001). In conclusion, dam parity of origin is associated with differences in early-life performance, reproductive output, and reasons for removal across the productive life. These differences were incremental and accumulated over parities, indicating that dam parity acts as a risk modifier rather than a deterministic factor for sow longevity.