Non productive sow days per batch (NPD)


These are days when the sow or gilt is not being productive - when she is not pregnant or lactating.

There is often too much made of NPD.

With batch farrowing, there is no impact of NPD on pigs finished.

However, NPD can be used as a means of helping investigate the reproductive efficiency on the farm.

The spreadsheet below provides a guide to calculate NPD on your farm and provides a basic what if concept which allows you to play with various options.

The original excel spreadsheet is linked here.

The programme will restore to default each time it is opened.

The default state are two farms with a 3% change in farrowing rate and 0.3 change in pig sold per farrowing place on a 10 sow a week farm

The default days are based on experience - you may need to review this with your own veterinarian and records.


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Analysis of returns

Summer infertility

Pig Flow models


Cost of feeding a sow or loosing production