11.   European officials insisted they would not be bullied into ending the ban imposed eight weeks ago because of fears about the mad cow disease infecting British cattle.

12.   Health inspectors are trying to piece together the family tree to determine whether other related cattle have been infected.

13.   Many scientists believe the cattle became infected with bovine spongiform encephalopathy, the formal name for mad cow disease, by eating parts of sheep with a similar ailment.

14.   Scientists believe that cattle became infected from eating feed enriched with ground up organs and nerve tissue from sheep.

15.   Scientists say the practice of supplementing cattle feed with sheep offal contaminated with the brain-wasting disease called scrapie infected British cattle.

16.   The ban was imposed last year because of mad cow disease infecting British cattle.

17.   The wildebeest themselves present a danger, carrying diseases that infect the cattle beloved of Maasai herders who live on both sides of the Tanzania-Kenya border.

18.   According to one popular theory, scrapie leapt the species barrier to cows, infecting cattle that ate the ground-up remains of sheep.

19.   It can also infect cattle, sheep, cats, dogs and rats, but is most dangerous for piglets aged less than seven days.