Non Productive Days (NPD) is the sum of non-productive days, when sow or sows were open or non producing during the analyzed period.
For NPD calculation, NPD will not count after the fallout of the female.
It is considered that the productive life of the sow on the farm goes until her culling.
1- If there was no farrowing on the farm during the period, just make a simple sum of non-productive days of the sow according to examples described below.
2-For reproductive losses from automatic matings generated in the purchase of the pregnant sow, consider the period since mating, even when the female enters the farm after mating.
EXAMPLE 01-SOW CARD
Current Date = 03/20/2017
EXAMPLE 02-SOW CARD
As there was no farrow, add the non productive days:
22 + 3 = 25