Estimation of lifetime productivity of female swine

Objective-To develop estimates of lifetime productivity for breeding female swine calculated longitudinally during time in the breeding herd, and to c ompare estimates of lifetime productivity for female swine removed from the herd at different parities. Design-Retrospective cohort study. Animals-9,416 breeding female swine from 29 herds. Procedure-A frequency distribution for parity at the time of removal was ge nerated. Estimates of lifetime productivity (lifetime nonproductive days [N PD], lifetime NPD as a proportion of herd life, total number of pigs born p er litter weaned, number of pigs born alive per litter weaned, number of pi gs weaned per litter weaned, number of NPD per year in the herd, number of litters weaned per year in the herd, and number of pigs weaned per year in the herd) were calculated for females with parity greater than or equal to 1 at the lime of removal. Results-For 58% of all females, parity at the time of removal was less than or equal to 3. On average, 20.7% of herd life was spent in nonproductive a ctivities, but the proportion of herd life that was nonproductive decreased significantly as parity at the time of removal increased. Number of NPD pe r year in the herd decreased and number of litters weaned per year in the h erd and number of pigs weaned per year in the herd increased significantly as parity at the time of removal increased. Clinical implications-Higher parity at the lime of removal from the herd is associated with improved lifetime productivity for female swine. Parity at time of removal is commonly used as an approximation for lifetime producti vity, but it does not take into account the impact of NPD, especially NPD d uring early reproductive cycles.