It would seem that the whole business of certified Angus is a marketing strategy, to put a brand identification on what otherwise would be just another piece of meat. And it escalates -- today in the supermarket I saw "Certified Hereford Beef." This is what one industry source says about Angus -- it sounds like a focus on the bottom line:
"Angus beef hardly needs an introduction; it is renowned for its fine marbling texture and superlative eating qualities. The Angus given a minimal amount of days on feed will manage to repeatedly turn out Prime and Choice grade meats. The Certified Angus Beef program was the first of its class. It provides Angus beef producers an increase in the marketability of their stock directly leading to higher premiums. For the consumer, it provides a consistent eating experience and the assurance of knowing what one is purchasing. In order to qualify under the phenotype requirements of the CAB programs, the cattle must exhibit at least 51% black coloration as well as the absence of non-angus traits (Brahman humps, dairy cattle conformation). The surge in the CAB program has led to a wide-reaching escalation of breeding black into cattle stock, most often using Angus bulls." http://www.cattle.com/BreedsofCattle/angus.aspx
And getting certified as Angus beef does not mean a single breed (there are several as well as crossbreeds) or even that close to purebred:
"Cattle eligible for Angus influence beef programs based on genotype must have positive identification (ear tags, tattoos, brands, etc.) and be traceable back to provable (e.g.; registration papers) Angus parentage. Qualifying cattle must be traceable to one registered parent or two registered grandparents. Programs which claim a specified percentage of Angus heritage must use this method.
Cattle eligible for certification in Angus influence beef programs based on phenotype (appearance) must be predominately (51 percent) solid black. Blue roan, gray, etc., are not considered to be black or a percentage of black. Such variations can qualify only when it occupies 49 percent, or less, of the body area with the remaining 51 percent, or greater, being solid black. Angus influence cattle may be either horned or polled. Carcasses of certified live animals which display certain non-Angus characteristics (e.g.; dairy conformation, Brahman humps) shall be excluded as specified in the carcass specifications for approved programs." http://www.ams.usda.gov/lsg/certprog/Schedules/sched-GLA.htm