BSE is Bovine Spongiform Encephalopathy, also known as mad cow disease. BSE eventually cause cattle to lose control of their bodies. It is caused by an abnormal protein in the brain and it can also be spread through feeds.
You may be aware of BSE or Bovine Spongiform Encephalopathy by another name, "Mad Cow" disease. Basically this is a disease that attacks the brain and is fatal.
