Previous studies1–6 have identified reproductive problems as the most frequently cited reasons for removal of sows from commercial swine herds. Lucia et al,2 for example, reported that 33.6% of 7,973 sows removed from various herds had been removed because of reproductive disorders. In contrast, Koketsu et al7 reported that only 10% of the total sow inventory on the farms they examined had been removed for reproductive reasons, and Friendship et al4 reported that reproductive problems were the most commonly cited reasons for removal of sows during the summer, but that other seasonal patterns were also observed. Other commonly reported reasons for sow removal include low litter productivity, which has been reported to account for 8% to 17% of sow removals, and old age, which has been reported to account for 9% to 24% of sow removals.1,4–6,8,9
Productivity-associated sow removal and replacement can be considered a successful management strategy only if reproductive performance of the replacement animals (eg, number of PBA/MF/Y) is greater than reproductive performance that could have been expected had the removed animals been allowed to remain in the herd. To our knowledge, however, there are no published studies comparing reproductive performance of replacement animals with anticipated reproductive performance of sows removed from commercial swine herds for defined reasons. The purpose of the study reported here, therefore, was to evaluate the success of removal and replacement decisions for sows removed from 3 commercial swine herds because of reproductive problems, low litter productivity, or old age.
Pigs born alive per mated female per year
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Lucia T Jr, Dial GD, Marsh WE. Lifetime reproductive performance in female pigs having distinct reasons for removal. Livest Prod Sci 2000;63:213–222.
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Koketsu Y, Dial GD. Factors influencing the post-weaning reproductive performance of sows on commercial farms. Theriogenology 1997;47:1445–1461.
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