It's true that the heterozygous carriers have more muscle but a breeder either commercial or purebred really needs to know what they have. The homozygous double carriers definitely have issues from calving through thriftiness and require much more attention and can with the higher incidence of dystocia increase vet costs, as well as calf or even cow losses. If one knows they have carrier cows it would in most cases be best to use bulls that are free of disruptive myostatin variants. For example a carrier cow that produces calves averaging in the low 90 lb range can present a calf that is a 130 to 140 lbs if it carries two myostatin variants.Willow Springs said:The e266x variant seems to be the most prominent in the Canadian population with some very popular and heavily used lines being carriers. And that is no surprise as it appears in the heterozygous state it gives the animals more muscle expression which is generally a positive in our industry.
Yes we test all our herd bulls and any of the bulls we sell. Since we started testing we have been selling only bulls that are free of the variants. We have been doing this for several years now and last year we had only one carrier bull calf but that might have been a bit of luck. We have only had experience with the E226 variant found most commonly in Shorthorns and Maine Anjou and it is a disruptive variant. The E226 variant can cause some significant calving issues when a calf gets a copy of the variant myostatin from each parent. We want to continue to develop our commercial bull market so if the bulls we sell are free our customers do not have to worry. We have started testing some of our females but have not got them all done as of yet. If you have the right environment, facilities and time you may find that you can deal with the issues to get the extra yield but typically a homozygous carrier is less thrifty and may have difficulty covering the ground to graze. If your cows are free and you use a carrier bull you should get increased yield on the calves but you will need to manage what the heifers are bred to. Typically the expense of testing cows for genetic defects is not easily borne by a commercial producer or a purebred herd for that matter. Knowledge of what you have is power though so testing at very least ones herd bulls should be worthwhile.beebe said:Okotoks, is the Myostatin gene something that you test for and try to avoid?
Unfortunately we have used some E226 carrier bulls. I think the extra muscling is obviously attractive to breeders just as TH was and I bit both times :-\. As with any recessive defect it takes a few years to show up up and we had the misfortune of using a couple of light birth weight carrier bulls on our yearling heifers some of which were carriers. When the calves were homozygous it was bad at calving. We started testing then and have tested all our herd sires and sale bulls since. Carriers with one variant only can have quite a range of muscle expression and we found several surprises both ways with results. If they had two copies it was more than obvious. I could give you a rather long list of known tested carriers and suspected carriers (not tested but sires of affected calves). I would suggest using the DNA tab on digital beef to check if a potential herd sire has been tested.Worthwhile if you do or do not want carrier animals) You will find some of the best bulls in the breed are carriers so in that case one might want to select and mate around it. Two bulls with a strong influence in our herd which we still value are Diamond Captain Mark 27C and Northern Legend 3N and will be tested to confirm that they are carriers but both have confirmed offspring. Although a somewhat different muscle pattern but still appealing are bulls like Diamond Belvedere 29B and Hatfield Bingo 2F. They are free but have good muscle expression, Belvedere's genomically enhanced EPD for REA is in the top 10% of the breed!Willow Springs said:Dan have you seen any double carriers of e266x? I have a three potentials (ET calves), but I think 2 of 3 are likely single carriers as they are normal looking, but just show more muscle and bone - also very large BW versus the third calf who looks like the other non carrier calves I have. I did see one this spring at another farm that was likely a double carrier of e266x and he was small, finer boned and heavier muscled.
Do you have a recommendation as to where to test?Okotoks said:Unfortunately we have used some E226 carrier bulls. I think the extra muscling is obviously attractive to breeders just as TH was and I bit both times :-\. As with any recessive defect it takes a few years to show up up and we had the misfortune of using a couple of light birth weight carrier bulls on our yearling heifers some of which were carriers. When the calves were homozygous it was bad at calving. We started testing then and have tested all our herd sires and sale bulls since. Carriers with one variant only can have quite a range of muscle expression and we found several surprises both ways with results. If they had two copies it was more than obvious. I could give you a rather long list of known tested carriers and suspected carriers (not tested but sires of affected calves). I would suggest using the DNA tab on digital beef to check if a potential herd sire has been tested.Worthwhile if you do or do not want carrier animals) You will find some of the best bulls in the breed are carriers so in that case one might want to select and mate around it. Two bulls with a strong influence in our herd which we still value are Diamond Captain Mark 27C and Northern Legend 3N and will be tested to confirm that they are carriers but both have confirmed offspring. Although a somewhat different muscle pattern but still appealing are bulls like Diamond Belvedere 29B and Hatfield Bingo 2F. They are free but have good muscle expression, Belvedere's genomically enhanced EPD for REA is in the top 10% of the breed!Willow Springs said:Dan have you seen any double carriers of e266x? I have a three potentials (ET calves), but I think 2 of 3 are likely single carriers as they are normal looking, but just show more muscle and bone - also very large BW versus the third calf who looks like the other non carrier calves I have. I did see one this spring at another farm that was likely a double carrier of e266x and he was small, finer boned and heavier muscled.
Neogen does the Canadian Shorthorn Association's DNA testing. We usually do the mysostatin on our bulls now bundled with the 50K and get a savings on the myo test and the 50K gives us parentage testing and genomically enhanced EPD's. Since bulls in Canada have to have a DNA parentage test before you can register calves it's an added value to our customers as well.beebe said:Do you have a recommendation as to where to test?Okotoks said:Unfortunately we have used some E226 carrier bulls. I think the extra muscling is obviously attractive to breeders just as TH was and I bit both times :-\. As with any recessive defect it takes a few years to show up up and we had the misfortune of using a couple of light birth weight carrier bulls on our yearling heifers some of which were carriers. When the calves were homozygous it was bad at calving. We started testing then and have tested all our herd sires and sale bulls since. Carriers with one variant only can have quite a range of muscle expression and we found several surprises both ways with results. If they had two copies it was more than obvious. I could give you a rather long list of known tested carriers and suspected carriers (not tested but sires of affected calves). I would suggest using the DNA tab on digital beef to check if a potential herd sire has been tested.Worthwhile if you do or do not want carrier animals) You will find some of the best bulls in the breed are carriers so in that case one might want to select and mate around it. Two bulls with a strong influence in our herd which we still value are Diamond Captain Mark 27C and Northern Legend 3N and will be tested to confirm that they are carriers but both have confirmed offspring. Although a somewhat different muscle pattern but still appealing are bulls like Diamond Belvedere 29B and Hatfield Bingo 2F. They are free but have good muscle expression, Belvedere's genomically enhanced EPD for REA is in the top 10% of the breed!Willow Springs said:Dan have you seen any double carriers of e266x? I have a three potentials (ET calves), but I think 2 of 3 are likely single carriers as they are normal looking, but just show more muscle and bone - also very large BW versus the third calf who looks like the other non carrier calves I have. I did see one this spring at another farm that was likely a double carrier of e266x and he was small, finer boned and heavier muscled.
Myostatin is real and it needs management! It takes a carrier bull to follow a carrier bulls daughters to find that out. (Typically it just drifts along in a herd until you bring in that second bull. A neighbor of ours bought a small herd with some very good cows in it. The last year the young cows had been bred back to their half brother(their sire was a purchased bull and was a great bull with great all round EPD's, actual weights and eye appealing moderate offspring) Long story short three difficult vet assisted deliveries, one dead calf. He bought a myostatin free bull and this year the problem was solved. At our annual Alberta meeting this year a breeder stood up and said he had believed exactly what Xbar states above but after this calf crop using a carrier on carriers he said the myostatin test was cheap and the issue real! It's all about getting the information and managing it. You can use carriers but in my experience using them back on carrier cows is an expensive mistake. It's not just a Shorthorn problem, it exists in several breeds.mark tenenbaum said:What about your cows? Do you think there may be comparable traits? Myostaten doesnt appear to have been on the radar (in terms of testing- sale annonucements) very long. The only reason I brought this up in your case is it seemed like a freak deal of sorts-You always seemed to go for functional cattle with non-off the wall traits-maybe there"s something in the woodpile that nobody would have been aware of a few years ago But in my ever so humble opinion: THERE IS NO REASON to dismiss or to dispose of good cattle Or" who struck John?" knowingly or not. Some of the Canadian cattle per example are way good-Just breed em clean if they work for you O0