What is the origin of the idiom "neck and crop" and when to use it?

The idiom "neck and crop" is a somewhat dated expression with origins in agricultural and equestrian contexts. It is derived from the practice of killing animals or harvesting crops entirely, without leaving anything behind. In this context, "neck" refers to the head and upper part of the animal, and "crop" refers to the harvest. Over time, this idiomatic expression has been used more broadly to indicate complete and thorough actions or consumption.