Calculating the age and weight of the finishing pig

This spreadsheet below provides a guide to the expected target weight of a pig at different ages.

This calculation is based on the formulae:

Age days = (-0.0744*POWER(((bwt/10)+1),2)+2.7618*((bwt/10)+1)-0.2818)

bwt = live body weight in kg

This works well, up to 120 kg but as the pig matures to final weight the correlation between the formula and reality become more unreliable.  But within its limitations the formulae provides some interesting results.

Eventually at heavy weight the pig gains weight and looses age - if only reality was so kind!