We got a letter from the abattoire saying that the GOS we sent for slaughter last week weren't slapmarked well enough so really I'm wanting any advice on how to improve the clarity of the mark. We have a slapmarker that has lots of pins with our letters and numbers and Tattoo ink. My husband did the actual marking and hit the pigs pretty hard - on one of them he said he sort of felt the slapmarker stick in the skin, but not on the other attempts.
What can we do to improve our technique with the next lot of pigs we have please?