An Alley Scraper is a "V" shaped mechanical blade that is dragged over an Alley by chain or cable to pull Manure to collection channel at the end of the Alley (or possibly the center of the barn).

The blade then collapses and is drawn back to the opposite end of the alley.

Other /More definition:
An Alley Scraper is a "V" shaped mechanical blade that is dragged over an alley by chain or cable to pull manure to collection channel at the end of the alley (or possibly the center of the barn). The blade then collapses and is drawn back to the opposite end of the alley.