One thing I've learned from watching pigs is that the trusting pigs typically get slaughtered first. That's bothered me, because it seems so unfair - but it is how the world works, so there's an important lesson there.
I've got less concern about the following observation: it never pays to be the fastest growing pig that bullies the others and eats their feed. Such pigs generally get killed first.
I was reminded of that today because a feeder pig customer (John Besh's La Provence) said they were going to kill their biggest pig. They need some meat for an event on short notice, so rather than ordering in Mangalitsa, they'll just kill the biggest pig and take what they need.
Their plan was to grow their pigs out to full size - but circumstances intervened. The slower-growing pigs are likely to live the longest.
I don't know if they killed their biggest pig - but as a rule, when it is time to kill N pigs, you sort them and grab the N biggest pigs. Obviously the pigs that really stand out as big are most likely to go to slaughter.