S H O P O U R S T O R E
Genetic defects: Ask, check pedigree or test
If you raise cattle, you may have heard of the many genetic defects that have become evident in recent times. The two that have gotten the most attention, probably because they came from one of the most popular genetic families in the Angus breed, are commonly known as Curly Calf and Waterhead. They both have long, hard-to-pronounce scientific names, but if you refer to the common names or the abbreviations of the scientific names, which are AM and NH respectively, anyone involved in the seedstock business will likely know what you are talking about. Curly Calf or AM, is a simple lethal recessive found in some offspring of the Angus bull 9J9, the best known of which is Precision 1680.
A simple lethal recessive is a genetic trait that is controlled by just one gene. If the lethal form of the gene is inherited from both parents, the calf is born dead, or dies shortly after birth. The problem is that carriers, or animals which inherit the gene from only one parent, look entirely normal to the eye of even the best animal evaluator, but if a carrier is mated to another carrier, 25% of their offspring will be born dead, with 50% carriers and 25% normal non-carriers. So how do you control the problem in your herd? For commercial cow-calf producers, it’s remarkably easy. Just make sure that when you purchase bulls, your seedstock provider has either tested the bulls to confirm that they are free of known genetic defects or that they come from clean pedigrees. If you already own bulls that you want to continue to use, but they come from suspect pedigrees, a $25 test utilizing a few hairs pulled from the tail switch can answer any questions you might have.
- Waterhead or NH, is also a simple lethal recessive, which also comes from the Precision 1680 family of Angus cattle and it can be controlled by the very same means, purchase and use only clean pedigrees or bulls that have been tested free of the recessive form of the gene. Commercial herds don’t need to worry if their cows are carriers of the “bad” form of the genes as long as only clean bulls are used. And don’t forget that Angus genetics are found in more than just Angus cattle. If you use black-hided Continental bulls or composites of those breeds and Angus you must be aware of the Angus component of that bull and insist on either a clean pedigree back to when Angus was introduced into the mix or on testing those animals that are potential carriers.
- Other genetic problems found in today’s seedstock are marble-bone in Red Angus, TH and PHA in Maine-Anjou and related breeds and several others that are relatively uncommon but should be monitored. The best advice is to work with your seedstock supplier to identify potential problems and then get any suspect bulls tested.
If you AI, it’s unlikely that you will be able to buy semen for known carriers of lethal recessives. Most of the reputable suppliers of semen, including Select Sires, have removed known carriers from their catalogs and tested or otherwise proved clean the bulls that are listed. The “clubby” bulls might be the exception, where you might find some carriers of TH or PHA. That is one advantage of using AI on your herd. All bulls from the Select Sires catalog have not only been tested for the known genetic defects, but have also been parentally verified by DNA analysis, so you know the pedigree that is represented in the catalog is the true pedigree and that a mistake has not been made when reporting the sire and dam of the bull in question.
Give us a call at WW Feed & Supply if you have more questions about genetic defects and how they might affect your cowherd or if you just want to explore the advantages of using AI in your herd.