1. Well it is the same principle with an adult and a baby. When a baby is born, it is basically helpless and simply cannot survive on its own. It needs its mother’s protection, love and nutriment to grow and become a strong adult. This is same for a chicken. When a chicken egg is hatched, the baby chick is hungry and helpless and needs its mothers help for food and protection until that baby chick is able to fend for itself. So you see, the chicken must have come before the egg.
2. If you look at it also from a Biblical perspective. God created animals, lion, tiger, deer, monkeys, fishes, etc. It never said God created eggs, tadpoles, cubs etc.
3. The Egg Needed a Rooster and a Hen To Create It. The chicken egg on its own could not have populated the world with so many chickens. The egg is created when the male chicken called a rooster copulates with a female chicken called a hen. So even if two eggs came first, there is no guarantee that those two eggs would have hatched a rooster and a hen which are needed to make other chickens.