Question: what is the difference between barn lime and ag lime?
Answer: When it comes to cutting down the ammonia in your horse's stall, lime just doesn't cut it anymore. That's so old school. ... Barn Lime (also referred to by some as, Ag Lime or Dairy Lime) has essentially zero, zilch, nada, ability to remove ammonia and odors. Barn lime is simply crushed up limestone, or Calcium Carbonate.