Could be the chain off of a set of cow shackles, which we called 'kickers'. These were attached to the rear legs to keep a cow from kicking the bucket while it was being milked. Haven't used a set since we quit milking in 1967.
There is a large ring centered in the chain with an even number of links to both sides. perhaps it was a center point for lifting ? hay, log or ice tongs come to mind.