In the Red Sex Link, the gene responsible for feather color is the sex-linked barring gene. The male chick receives a copy of the gene from the Rhode Island Red or New Hampshire rooster, while the female chick receives a copy from the White Leghorn hen. The interaction between these genes creates the distinct feather colors that make it easy to identify the sex of the chicks.
In the Black Sex Link, the gene responsible for feather color is the sex-linked silver gene. The male chick receives a copy of the gene from the Barred Plymouth Rock or Dominique rooster, while the female chick receives a copy from the Rhode Island White or Delaware hen. The interaction between these genes creates the distinct feather colors that make it easy to identify the sex of the chicks.
It's important to note that these sex link traits are specific to these particular breeds and crossbreeds. Other breeds may use different genes to create sex link offspring with distinct feather colors.