In order to make sure all interaction with the animals is as realistic as possible, Callum explained the cast had a crash course in handling animals.
He told Radio Times: “At the start of his career, Andy Barrett, our on-set vet, actually worked under the real Siegfried, a man named Donald Sinclair.
“He has all these amazing stories. He took us round the farms and introduced us to calves, cows, horses and pigs, telling us how to approach the animals and exactly how to hold our instruments. He adds such authenticity to the show.”
All Creatures Great and Small airs Thursday on Channel 5 at 9pm.