地平线系列：绿色畜牧

     Dr Michael Mosley seeks to establish the truth about meat       Every year, humans raise and eat 65 billion animals - nine animals for every person on the globe       In this eye-opening documentary, Michael examines the impact that this is having on the planet and finds out what meat eco-friendly carnivores should be buying       Is it better to buy free-range organic or factory-farmed meat?