Specified risk material (SRM) is the general term designated for tissues of ruminant

Ruminant

A ruminant is a mammal of the order Artiodactyla that digests plant-based food by initially softening it within the animal's first compartment of the stomach, principally through bacterial actions, then regurgitating the semi-digested mass, now known as cud, and chewing it again...

 animals that cannot be inspected and passed for human food because scientists have determined that BSE

Bovine spongiform encephalopathy

Bovine spongiform encephalopathy , commonly known as mad-cow disease, is a fatal neurodegenerative disease in cattle that causes a spongy degeneration in the brain and spinal cord. BSE has a long incubation period, about 30 months to 8 years, usually affecting adult cattle at a peak age onset of...

-causing prions concentrate there. The term was referred to in the United Kingdom's Specified Risk Material Order 1997 (S.I. 1997/2964), and in the United States Department of Agriculture

United States Department of Agriculture

The United States Department of Agriculture is the United States federal executive department responsible for developing and executing U.S. federal government policy on farming, agriculture, and food...

’s regulatory response to the first confirmed U.S. BSE case in December 2003.

These can include brains, eyes, spinal cord, and other organs; the exact definition varies by jurisdiction. Under the new regulations (69 FR 1862, January 12, 2004), SRMs are: the brain, skull, eyes, trigeminal ganglia

Trigeminal ganglion

The trigeminal ganglion is a sensory ganglion of the trigeminal nerve that occupies a cavity in the dura mater, covering the trigeminal impression near the apex of the petrous part of the temporal bone.-Relations:It is somewhat crescentic in shape, with its convexity...

, spinal cord, vertebral column (with some exclusions), dorsal root ganglia

Dorsal root ganglion

In anatomy and neuroscience, a dorsal root ganglion is a nodule on a dorsal root that contains cell bodies of neurons in afferent spinal nerves.-Unique unipolar structure:...

 (DRG) of cattle 30 months of age and older, and the tonsils and distal ileum

Ileum

The ileum is the final section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms posterior intestine or distal intestine may be used instead of ileum.The ileum follows the duodenum...

 of the small intestine of all cattle.

BSE

The BSE infective agent has been found to concentrate in specific tissues of BSE-infected cattle and these tissues are all part of the central nervous system

Central nervous system

The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...

, as BSE has not been shown to infect muscle.

BSE SRMs

In both the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 (U.S.) and Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, considered low risk countries, SRMs are defined as: skull

Skull

The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...

, brain

Brain

The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

, trigeminal ganglia (nerves attached to brain and close to the skull exterior), eye

Eye

Eyes are organs that detect light and convert it into electro-chemical impulses in neurons. The simplest photoreceptors in conscious vision connect light to movement...

s, spinal cord

Spinal cord

The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...

, distal ileum (a part of the small intestine

Small intestine

The small intestine is the part of the gastrointestinal tract following the stomach and followed by the large intestine, and is where much of the digestion and absorption of food takes place. In invertebrates such as worms, the terms "gastrointestinal tract" and "large intestine" are often used to...

), and the dorsal root ganglia (nerves attached to the spinal cord and close to the vertebral column

Vertebral column

In human anatomy, the vertebral column is a column usually consisting of 24 articulating vertebrae, and 9 fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs...

) of cattle aged 30 months or older. On January 12, 2004, the Food Safety and Inspection Service (FSIS) of the USDA published new rules banning such materials from the human food supply.

In the United Kingdom

United Kingdom

The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, and other countries classified as moderate to high risk, the OIE code recommends SRM removal as follows: tonsils and intestines in cattle at all ages; brains, eyes, spinal cord, skull and vertebral column from animals over twelve months of age.

In the European Union

European Union

The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...

 (E.U.), SRMs are excluded by law from the human and animal food chain.

Removal of BSE SRMs

The World Organization for Animal Health (OIE) has established recommendations and guidelines for SRM removal based on the level of risk. In the U.S., tonsils are removed from cattle of all ages. SRMs must be removed at slaughter and disposed as inedible material. The dorsal root ganglia must be removed during the deboning process and in animals older than 30 months, the vertebral column (excluding the vertebrae of the tail, the transverse processes of the lumbar

Lumbar

In tetrapod anatomy, lumbar is an adjective that means of or pertaining to the abdominal segment of the torso, between the diaphragm and the sacrum ...

 and thoracic vertebrae

Thoracic vertebrae

In human anatomy, twelve thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. They are intermediate in size between those of the cervical and lumbar regions; they increase in size as one proceeds down the spine, the upper...

, and the wings of the sacrum

Sacrum

In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...

) is removed to be certain the dorsal root ganglia is extracted in its entirety.