Ansätze zur züchterischen Verbesserung der Nutzungsdauer von Sauen.

Sow longevity is an important trait for both economic as well as ethical reasons. Data from all sows under recording in Bavaria indicated that over the last ten years important figures related to sow longevity were almost constant. This study included approximately 60.000 sows from commercial farms raised in multiplier herdbook farms. Longevity was defined as the ability of a sow to have a second litter after a first litter was recorded (stayability), and it was coded as a binary trait. For single-trait analyses of stayability, binomial models fitting a logit-link function as well as linear models were applied. Estimates of heritability were very low for both models (0,04 and 0,02, respectively). Estimates of genetic correlation between stayability and performance test and station test traits were moderate to considerable and unfavourable. Estimates of genetic correlation between stayability and fertility traits were slightly negative. For certain traits it can be very helpful to combine data from herdbook farms and data from commercial farms for breeding purposes. Because of different selection strategies, data for longevity traits like stayability from commercial farms may be more informative than data from herd-book farms. [ABSTRACT FROM AUTHOR]