By Jenelle Dunkelberger and Torunn Aasmundstad
Topigs Norsvin has selected for enhanced sow longevity for over a decade. Much of the data used to facilitate genetic improvement in our lines is collected at nucleus farms. Sow longevity, however, is not one of the traits measured at these locations.
Given the need to continuously evaluate the latest generation of animals, the replacement rate at nucleus farms is artificially high, which means the genetic potential for longevity cannot be evaluated. As a workaround, Topigs Norsvin partners with a large commercial farm in the US, where detailed removal and genetic information are captured on each individual. These data are linked to other animals in Topigs Norsvin’s database and used to facilitate selection for enhanced overall sow longevity.
The top three reasons for sow death loss are unknown/sudden death, feet/leg structure, and vaginal/uterine prolapse. Genetic improvement in unknown/sudden death is addressed by selecting for enhanced longevity in general, as described above. Explicit selection for improved feet/leg structure and reduced susceptibility to vaginal/uterine prolapse is also part of Topigs Norsvin’s breeding program. For instance, selection against osteochondrosis, the main cause of leg weakness, has been underway since 1990 and selection against susceptibility to vaginal/uterine prolapse has been underway since 2021.
