Generally by 5 weeks you will really notice slight differences in comb size, length of the legs, size of the feet and presence of saddle feathers.
Day one if you are VERY EXPERIENCED. Most hatcheries have people on staff (usually Japanese based on the need for sexing in a country with limited space) that sex day old chicks. They squeeze the chick to release fecal material then flip it over, open the vent and look for a small lump to determine male or female.
Silkies are hard chickens to find out their gender. Either you can vent sex them, which should only be done by a professional because you can hurt or even kill your chick. Or you can just wait until the chicks are old enough to lay eggs or if it crows.
Shell color is determined SOLELY by breed. Some lay white, some lay brown and some (Aracaunas and Americaunas) lay green. What they eat, the color of the feathers, have NOTHING to do with it. Also, there is absolutely NO difference in the nutritional value between them (assuming they've been fed the same diet). Some people INSIST that there is a difference in taste between brown and white eggs. Embarrassingly to them, though, taste tests have consistently proven they they CAN'T tell the difference!
The striped one always has
Look at the related answers.
A flock chickens, a brood of hens, and a clutch or peep of chicks.
A Black Star rooster has a white dot on its head, where the females do not. Black Stars as sex-link chickens meaning you can tell their sex by their color once hatched.
They belong to white
Not if the birds are young. The older birds have grown using muscles heavily and will be less tender but the flavor will be the same.
I am not sure if you are talking about a hen foot or a rooster foot as in math, because I have not heard of that, but if you are talking about the bird chicken, an adult rooster usually has a spur (hard, naturally pointed growth) just above his foot, while a hen usually has just a small bump in the same spot.
Silkies are hard chickens to find out their gender. Either you can vent sex them, which should only be done by a professional because you can hurt or even kill your chick. Or you can just wait until the chicks are old enough to lay eggs or if it crows.
By verbal communication, and even by sight. To a human all chicks peep the same, but to a mother hen, she can tell which chicks are hers and which are not.
http://www.youtube.com/watch?v=ircubXfYfdU&feature=related http://www.youtube.com/watch?v=QBFwVa0qW74&feature=related
If they have a comb
how can you tell the difference between a tortoise and a turtle by shell in picture
Can you tell the difference between Vyvanse and Concerta in a drug test
Let Me Tell Ya 'bout Black Chicks was created in 1985.
Vending machines have laser scanners that can tell the difference between the bills.