The figure was almost by the middle of the page, search for the string "AT THE FEEDLOT, CATTLE ARE FED A DIET OF 80% GRAIN AND 20% FORAGES. (SILAGE AND HAY)", on the section "Start weight, finish weight".

As for the others:
Here's the USDA source: https://www.ers.usda.gov/topics/crops/corn-and-other-feed-grains/feed-grains-sector-at-a-glance/:

Corn is a major component of livestock feed. Feed use, a derived demand, is closely related to the number of animals (cattle, hogs, and poultry) that are fed corn and typically accounts for about 40 percent of total domestic corn use. The amount of corn used for feed also depends on the crop's supply and price, the amount of supplemental ingredients used in feed rations, and the supplies and prices of competing ingredients.

And regarding soy, here's from the WWF: https://wwf.panda.org/discover/our_focus/food_practice/sustainable_production/soy/

We may not eat large quantities of soy directly, but the animals we eat, or from which we consume eggs or milk, do. In fact, almost 80% of the world’s soybean crop is fed to livestock, especially for beef, chicken, egg and dairy production (milk, cheeses, butter, yogurt, etc).

You obviously know way more than me about the subject but you gotta excuse me for taking anything from a website called "sacredcow" talking about the "plant-based industry" at the top of the page with a grain of salt, everything else I've seen online points to animal farming being incredible inefficient and a huge contributor to global warming and water waste.