What's in a Bale of hay does not stay in the Bale

When a chunk of metal this size (12 X18 inches) shows up in the feed bunker you have got to know there is a story and a lot of questions to be answered.  This is the arm of my hay Tedder.  I was not aware that it was broken so I went down to check it out and everything was intact.  That meant that this tedder arm was from two years ago.  That means that this hunk of steel evaded the baler two years ago and evaded being seen at that time or during fertilizing and that this year it probably went through the mower, and the tedder, and the baler and its slicer in order to appear inside a bale of hay.  My next move in the process is to check the slicers on my baler.  They either have to be broken or very dull!