Just watching Food Unwrapped on Channel 4. The presenter is in America on a beef cattle farm. (85% are kept in corrals like this) They have just explained that they feed their cattle corn, and because the cattle have come from grass pastures to these fattening yards and they are being just fed purely on corn, they go through a transition period where they need antibiotics administered and they also have a growth hormone implant in their ear.

Though, as my OH has pointed out maybe this is why most american males are so large) This has been banned in the EU. They are now showing a lovely herd of grass fed beef. They look fab. Only killed at 24 months.
Make sure you dont eat American meat. (something to do with the growth hormones.
It just shows how our food is being prepared and why we are getting to a stage where antibiotics are stopping working.
Now we are being shown how they make thick gravy in shop bought pies. Wood cellulose is being used as a thickener in shop bought pies to stop the gravy bursting out. !!!