Growth rate - effect on days to slaughter
The spreadsheet is a guide to the effect of a change of growth rate on the days to slaughter
Calculate your days to slaughter
Note with different batching systems this might not make any difference to your building requirements.
If you already have, say 20 wean to finish buildings, (4 week weaning) increasing the growth rate to 23 weeks will not impact output - unless you can divide the "spare" building into 19 air spaces to maintain your all-in/all-out or increase slaughter weight.
However, it might allow for a tighter group provide better cleaning options
Days to slaughter