For once, I have a complete set of figures which might help anyone trying to work out size and weights.
Two OSB boars, brothers, slaughtered at exactly 28 weeks old, feed regime 1.9 kgs/day each from 20 weeks onwards, graduated before that.
Pig A: measurements day before slaughter girth 1.025 m, length 1.31 m. Using G x G x L x 69.3 formula
comes to 95.38 kgs live weight. Slaughter weight 68.8 kgs (fat 15). 68.8 / 95.38 = 0.721 live weight.
Butchery: Cuts & joints 45.29 kgs (66.75%), bones from joints for spare ribs 3.634 kgs (5.36%), flare fat & kidneys 0.642 kgs (0.95%), sausage meat 4.148 kgs (6.11%), head 6.398 kgs (9.43%), waste 7.732 kgs (11.4%). These totals come to 67.842 kgs, which is 0.9861 of the pay weight of 68.8 kgs.
Pig B: measurements days before slaughter girth 1.02 m, length 1.28 m = live weight 92.29 kgs.
Slaughter weight 64.5 kgs (fat 16). 64.5 / 92.29 = 0.698 live weight.
Butchery: Cuts & joints 42.702 kgs (68.1%), bones from joints for spare ribs 0.866 kgs (1.38%), flare fat & kidneys 0.950 kgs (1.52%), sausage meat 4.232 kgs (6.75%), head 5.862 kgs (9.35%), waste 8.806 kgs (12.9%). These totals come to 62.698 kgs, which is 0.972 of the pay weight of 64.5 kgs.
With both pigs, some of the meat on the head was later used to add to the sausage meat, approx. 1 kg per head, so sausage meat weights and head weights would be that much more and less respectively. Also goes to show that two pigs, same gender, from the same litter, fed exactly the same all their lives, do not always end up the same weight at the end.