It is that animal matter, especially brains, spinal cords and other nerve tissue, that is believed to carry the BSE contagion to healthy cattle.
(It; is; that animal matter) (other nerve tissue; is believed; to carry the BSE contagion to healthy cattle) (other nerve tissue; to carry; the BSE contagion; to healthy cattle)
It other nerve tissue other nerve tissue
is is believed to carry
that animal matter
to carry the BSE contagion to healthy cattle
the BSE contagion to healthy cattle