An immature female sheep is called a "ewe lamb." Ewe lambs are young female sheep that have not yet reached maturity or had their first offspring. Once they mature and give birth, they are referred to simply as ewes.
A ewe lamb
An immature female duck is called a duckling. Once the female duck matures it is called a hen or duck.
An immature female sheep is called a ewe lamb. An immature male sheep is called a ram lamb.
An immature sow
An 'Abby"
Kid. Other opinion: They can be known as bucklings. If it has been castrated then it would be called a wether.
An immature female chicken is called a pullet. This term is typically used to refer to a young female chicken that has not started laying eggs yet.
It is known as a yearling or a Filly. Yearling applies for any gender that is roughly a year old and is still immature. An adult female horse is known as a mare.
An immature female cat is called a "kitten." This term is used to refer to young cats until they reach adulthood, typically around one year of age.
A female horse is called a mare. A female horse that is 4 or under is called a filly.
A male donkey is called a Jack and a female donkey is called a Jennet.
A pig is either male or female. A male intact pig is called a boar, a male castrated pig is called a barrow, a mature female is called a sow and an immature female is called a gilt.