Which of the following are considered specified risk materials (SRM) in cattle of all ages?

Specified risk materials (SRM) in cattle are specific tissues that are considered to pose a higher risk for transmitting Bovine Spongiform Encephalopathy (BSE), also known as Mad Cow Disease. The identification of these materials is critical for public health and food safety.

The correct answer highlights tonsils and the distal ileum as SRM in cattle of all ages. The tonsils are a significant risk site because they can harbor infectious agents. Similarly, the distal ileum of the small intestine is notable as it is where certain pathogens may be present and can be absorbed into the body.

The other options refer to other anatomical parts; however, they do not qualify as SRM for all ages of cattle. Understanding SRMs is crucial for ensuring proper inspection and handling of cattle products to mitigate the risk of BSE transmission.