slapmarking should be done the day the pigs go to slaughter or the day before it is meant to identify a pig after it has went through the killing process if it has been done right it is visible even after skinning
metal tags survive the killing as well as does plastic but some slaughter houses prefer slapmarks or metal tags
it has to be done quite hard to penetrate the skin it can be done on each rear ham or on all the four shoulders
That is simply not true Robert - Slapmarking can be done at any time from 10 Weeks old, that is why there are 10mm characters available so you can slap a weaner and the tattoo grows with the animal to slaughter weight. It is a matter of personal preferance when to slapmark, you cannot dictate that it is done the same day or the day before - There is no right and no wrong time to slapmark. I have to hand reports of the trails carried out on the ink we provide and the results are the same if the animals are slapped way in advance of slaughter or on the same day.
Some would argue that it is best not done on the day, as this can add to the stress levels of the animal leading to an increase of adrenilin and so a tougher carcass.
On the subject of plastic tags, I personally would refuse to sell a plastic slaughter tag for pigs, for pedigree markings then yes, but for Slaughter the regulations are quite clear (in England) that it needs to be a metal tag that will withstand the slaughter process, or a slapmark on each shoulder.
My personal view is that a slapmark is far superior to a tag for the following reasons:
1) There is 100% certainty that you are getting your own animal back as the tattoo can not be removed by the slaughter process - and despite what you may think tags do sometimes get pulled out.
2) Shoulder slapping is less stressful to the pig than being restrained while a tag is inserted
3) That 100% of large commercial producers use slapmarks rather than tags.
Rant over thanks :-)