“I don’t know what happened to the 40 sheep, pigs and Brahman bull,” Deach said.

Any time a virus jumps from one species to another, it runs the risk of mutating to become more primed for human-to-human transmission, which is why it's so concerning when the virus jumped to pigs for the first time on record last year.

Budget supermarket Lidl said it had the most successful Christmas in its history, boosted by people buying festive food such as pigs in blankets and turkey.

Revenue rose almost 7% to more than £1bn over the four weeks to Christmas Eve as customers bought 16 million pigs in blankets and a turkey every second.

"You can do pigs in blankets; they will take about 10 minutes at 190C," she said.