Even with commercial herds we always have feed charts with the number and type of pigs in each paddock, so an accurate count is done every day at feeding. I have charts for the smaller rare breeds and wild boar here as well.
The only thefts I have had to date have been batteries for the fencing units, with so many visitors to the farm, and several well used paths, there is ample opportunity for the dishonest community to plan minor raids.