Feeding the steers

So in the often mentioned Omnivore's Dilemma, Pollan buys a male calf and follows it through the farm system.
While he's on the "fatten them up fast" farm (i.e. where they exist before being sent to the slaughterhouse) - and incidentally, with the steroids and fat diet they give these creatures, they have them reaching kill weight in about 14 months these days, compared to 4 to 5 YEARS in the first half of the 20th century -

where was I... oh yeah, so Pollan is on the farm and visits the feed mill. They dump the corn in from one side (and cows are naturally grass eaters, and developed their famous four stomachs in order to do so. To get them eating the more quickly fattening corn diet, they have to drug them up so that their bodies can handle the corn) and the drugs etc from the other:

Around to the other side of the building, tanker trucks back up to silo-shaped tanks into which they pump thousands of gallons of liquefied fat and protein supplements. In a shed attached to the mill sit vats of liquid vitamins and synthetic estrogen beside pallets stacked with fifty-pound sacks of antibiotics - Rumensis and Tylosin. Along with alfafa hay and silage (for roughage), all these ingredients will be automatically blended and then piped into the parade of dump trucks that three times a day fan out from here to keep Poky's eight and a half miles of trough filled.

.... [corn kernels were] the only feed ingredient I sampled, and it wasn't half bad; not as crisp as a Kellog's flake, but with a cornier flavor. I passed on the other ingredients: the liquefied fat (which on today's menu is beef tallow, trucked in from one of the nearby slaughter-houses), and the protein supplement, a sticky brown goop consisting of molasses and urea. The urea is a form of synthetic nitrogen made from natural gas, similar to the fertilizer spread on a farmer's fields].

How'd you like to have all that crap in your body? And hey, the liquefied fat is beef tallow from a slaughter-house? Isn't feeding cows back to cows how mad-cow disease got started?

And I won't type much more, but Pollan goes on to explain how corn-fed beef is "demonstratably less healthy for us, since it contains more saturated fat and less omega-3 fatty acids than the meat of animals fed grass."