the fertilizer thing is new too ... maybe based on cows behavior to gathering in the top/north of the field. same as clay and metal worker.
https://www.file-upload.net/download-12660694/neu.txt.html
does that work?
turned the game of for lunch, after lunch i saw the dung disappearing. 2nd time the savegame was loaded.
the cow problem on the north-earth field seems to be fixed. placed the cows on the bottom of the field and they'll "normally" moving to the top of the field. in 6.2 they getting stuck under the grass-free strip.