That farting deer has caused a lot of problems. The song has always been famous and important, so dealing with that line when modernising it for school use has exercised minds considerably.I noticed in an earlier posting it was quoted as "browseth".This comes presumably from a specious explanation that "verteth" (so spelled in the original MS) was a word meaning "eating green shoots" (from French vert=green). Chappell in "Popular Music of the Olden Time" goes even more fanciful, saying that "verteth" means "frequents the green fern". I imagine he knew perfectly well what it meant, but was also aware what you could and couldnt publish in 1850.
Probably not a problem nowadays: I doubt if boring old songs(or farts) are part of the New National Relevant Curriculum.