Bovans Red, Bovans Brown, and Hyline Brown are all labels under which some hatcheries market their Red Sex Links, which are produced by crossing a red gene rooster (RIR, HN, or Production Red) with a silver gene hen (RIW, WPR, SLW, LS, Delaware, etc.). Not only can the resulting offspring be sexed by color at hatching (male chicks are whitish, female chicks are reddish), but they are egg laying machines, outlaying either parent breed. It's one of the interesting quirks of hybridization. Other labels under which Red Sex Links are marketed include Red Star, Brown Sex Link, Gold Star, Gold Sex Link, Golden Buff, Golden Comet, Hubbard Golden Comet, Isa Brown, Shaver Brown, Babcock Brown, Warrens, Gold Lines, Lohmans, Lohmans Brown, Brown Shaver, Red Shaver, Bovans Goldline, etc. I've had lots of Red Sex Links over the years which I've purchased under these different labels and with different silver gene hens used to produce them, and quite frankly, I can't tell any real difference in their lay rates. All Red Sex Links are egg laying machines, consistently churning out more than 300 eggs per hen per year. In addition to the Red Sex Links, there is also a Black Sex Link, which is produced by crossing a red gene rooster with a barred hen (usually a Barred Rock). Like RSLs, they are also egg laying machines, outlaying either parent breed. According to Murray McMurray, there is no difference in the lay rate of Black Sex Links and Red Sex Links (
https://www.mcmurrayhatchery.com/faqwhichbreedlaysbetterredstar.html), but in my own personal experience, I have found that my Black Sex Links have been slightly better layers in really cold winter weather than even my Red Sex Links have been. Black Sex Links are sometimes marketed by hatcheries under the labels, Black Star, Bovans Nera, or Rock Red.