Belted Galloway is a product of single trait selection (BLACK color & white belt) since Hector was a pup, hence the breed is as near to as ideal inbred as one can get. Genetics 101 taught me that the expression of heterosis ought to great when crossing Beltys with pretty much any other breed. So I did that using a Belty cross bull & got 70 calves over 5 years. I believe there was a greater expression of heterosis in the areas of health, udder soundness, reproductive efficiency, time to stand, time to nurse, and possibly feed conversion. Notice I said nothing about rate of gain. Belt is small frame breed, so when you cross a Belty - the offspring are still small.
It takes at least 3 generation to get rid of the belt using black Angus as a cross. The belt is gone in 2 generations using Red Angus as a cross. My hypothisis for this is there is a little Holstein blood floating around in the Angus breed (or maybe Chianina) which gives the belt trait a place to shine. If crossing a belt with some black Angus families it is gone in 2 generations, with other families like Fairfield High Guy - the belt actually gets bigger. EXT Angus bloodlines are prone to have big / hard to get rid of belts.
Breeding a clubby to a belty will get you a hairy dink. I am getting ready to try Charolais Belty cross to add frame & lose some hair - Bet they come out black too.
Consider the source when obtaining belties. Most herds are small & micro managed where things like rib eye area, yield, quality grade, rate of gain are rarely considered. Calving as 3 year olds & grass fed are often the focus...
Gelbviegh might be interesting - go for it