Their are a few left in Alberta and Manitoba. The breed is a Holstein Hereford Brown Swiss synthetic in make up and were designed to produce commercial cows out of Angus cows and maintain a black hide. They basically were/are a North American Simmental. The problem for the breed is that just as they were taking off the European imports came in and stole their thunder. Also the breeders were lousy promoters. The biggest production weakness for the breed can be bad bags on the cows. Not bad all around cattle but the Hays family controlled the breed and limited their population growth potential by wanting to maintain control.
Always had an interest in them - found the breed combo behind them to be interesting - but never saw any, or knew anyone here in the US who produced any.
Similarly, the RX3 cattle (composite developed by the Pioneer seedstock division, that was essentially 1/2 Red Angus, 1/4 Hereford, 1/4 Red Holstein) looked like they'd be pretty doggone good. There were still a fee RX3 breeders around the Midwest 15-20 years ago, but I've not seen anything about them in a long time.
I guess both ended up taking a backseat to the Simmentals, Gelbvieh, Chi, etc. - but it sure seemed like they brought something to the table; maybe it just wasn't enough...
There are still a few people raising Hays Converters in Western Canada, but their numbers are falling every year, not because they are poor cattle, but because of the poor promotion that has been mentioned in a previous post. We always had a pen of Hays Converter bulls at the Saskatchewan Livestock Center when it was operating at Regina and there were always some impressive bulls in the pen every year. They reminded me of the Friesan breed that were imported from the UK.
When we went to Beef Genetics Research Inc, at Mankato, KS to see the first Irish Shorthorns they had brought to North America, we also saw many Friesan cattle they had imported. They were by far the best cattle we saw there, including the Shorthorns and large herd of Simmentals as well. They were black with white faces. They were thick and very well muscled. The few females in production we saw had beautiful udders. I remembered being impressed with how feminine and fertile the females looked and the bulls were masculine and meat machines. I also remember Dick Judy saying that the biggest problem the Friesan cattle would have in the US would be their color pattern. I think he was right. Cattlemen do not consider BWF cattle as being purebreds.
The Hays Converters were very similar to these cattle. They were produced by Senator Harry Hays on his Alberta ranch and after many years of selection, they were able to obtain pure breed status from Agriculture Canada. Harry Hays designed this breed as he wanted to develop a breed that could work well in ranch conditions that had a bit more size and yet retained their ability to adapt to dry years and still come in each fall with a big calf and were safe in calf again. Had the influx of the European breeds been delayed for a few more years, I think this breed would have had a bigger acceptance in Canada.
Hays Converters were incorporated under the Live Stock Pedigree Act in 1975 but the development of the breed started in 1959. As with many of the smaller breeds they have had trouble expanding their base. I don't beleive they have had a lot of promotion. I saw a herd eight years ago and they were similar to the photos in the attached link.
The simm hereford cross only looks like a hays converter if blavk simmentals are involved. Right now Fleckvieh hereford bulls are being marketed with traditional hereeford markings: http://canadasbulls.com/bulls/h-2-horned-hereford-x-simmental-hybrid-bulls/
By the way the Hays Converter had another problem to over come: The large dairy influence. People used to hoke about any hereford holstien cross as a Hays Converter...
There are about 8 active members with Hays cattle still in Canada. Of them 120 purebred cows in Manitoba, and the original Hays Converter herd has been donated to the university of Alberta - about 80 purebred cows. commercially in 2021 there will be about 400 cows bred to Hays bulls.
All the comments are correct on promotion (lack there of).
The modern Hays cows still have a ways to go but they make great halfblood cows when crossed up with angus or other British based herds.