For the dataset used in this analysis, the mean LSY was 2.43.
This value is approaching the greatest average LSY that can be
achieved with weaning at 28 days, but there is still room for
improvement.
It is possible to achieve 2.47 LSY with a gestation
length of 115 days, and a 5 day wean to estrus interval.
This assumes
each sow is successfully mated at the first service. The
average LSY is calculated as 365/(115+5+28).
The denominator
is the farrowing interval for a sow that is successfully
mated as soon as she comes into estrus after weaning.
A herd
LSY of 2.43 may suggest that the calculation for LSY is biased
upwards since this is achieved only with a near perfect record
for each sow in the breeding herd.
Gilts were entered into the
breeding herd after being mated, hence non-productive day accumulation
does not occur until after the sows have weaned
their first litter.