None.
the skull including the brain and eyes, the tonsils and the spinal cord of bovine animals aged over 12 months, and the intestines from the duodenum to the rectum of bovine animals of all ages;
the skull including the brain and eyes, the tonsils and the spinal cord of ovine and caprine animals aged over 12 months or which have a permanent incisor erupted through the gum, and the spleen of ovine and caprine animals of all ages.
the entire head (excluding the tongue), including the brain, eyes, trigeminal ganglia and tonsils; the thymus; the spleen and the spinal cord of bovine animals aged over six months, and the intestines from the duodenum to the rectum of animals of all ages;
the vertebral column, including dorsal root ganglia, of bovine animals aged over 30 months;
the skull including the brain and eyes, the tonsils, the spinal cord of ovine and caprine animals aged over 12 months or which have a permanent incisor erupted through the gum, and the spleen of ovine and caprine animals of all ages.