Difference between sows & boars

Question
Newley acquired 1 sow & 1 boar and now have 4 beautiful babies.  How do I tell the difference between male & female and what is the earliest age I can do this.

Answer
You can tell the sex of the babies as early as when they are first born, it takes a little more skill at knowing what you are looking for, and sometimes you can get a baby that you really can't tell very well, usually ones with black skin, but for the most part you can be very accurate. What you have to do is get close to a lamp or light so you can see well, then turn the baby vertical with it's belly towards you, put one hand behind the front legs and other under it's bottom, then look at the bottom area, if it is a female you will see a small Y shape with a tiny slit in the middle, also if you push on the top of the Y you can see 2 small dots, most are white in color on either side of the stem of the Y shape. For males you hold them the same way, you will see a Y shape with a round dot in the middle, if you press up top the round area might extend depending on the age of the baby, you will not see the white dots on either side of the Y's stem. Usually with this technique you will always be right, but always re-check the babies at about 2 weeks, I have even had little babies fool me when trying to sex them from the first day, I have also notice that some guinea pigs have babies that are easier to sex than others, a lot depends on the size of the baby. Let me know if you have any more questions. Good luck with your new babies!
Brittany