Ewes rarely produce twins, and the breed is primarily used for wool production.

Whitetail deer, one of the few species to produce twins and triplets, can replenish their numbers by 40 percent a year, he said.

They are the only primate group that regularly produce twins, which constitute over 80% of births in species that have been studied.

We've found a way to make cows produce twins about eighty percent of the time.

The gestation period is six to seven months and they usually bear one offspring at a time but sometimes produce twins.

She produced twins: a boy and a girl.

Typically only one young is born, but in captivity they could rarely produce twins.

The marmoset mother produces twins or occasionally, in the laboratory, triplets.

Such techniques often produce twins, triplets or quadruplets, who are far more likely than single babies to be born prematurely, and tiny.

In some cases, those embryos might be split to produce identical twins, which would be implanted into different cows.