Earlier quoted context omitted.
86% of feed is grown on land [1], which is not suitable for growing human food crops. [1]: https://www.agfoundation.org/common-questions/view/could-mor...
You're quoting a literal farming foundation, so here is a neutral source: https://ourworldindata.org/land-use#half-of-the-world-s-habi... "If we combine pastures used for grazing with land used to grow crops for animal feed, livestock accounts for 77% of global farming land. Of all the land we use for agriculture, 77% of it is used for livestock." These 77% are only responsible for 18% of the produced calories and 37…
I doubt that 86% of that 77% is truly unsuitable for farming human food, but I wouldn't be surprised if 30-50% of it was.