The Van Trump Report

How One Bull Passed On A Deadly Gene to 14% of U.S. Dairy Cows

I found this story somewhat interesting and wanted to pass it along. In 1962, the Arlinda farm in Northern California purchased a milk cow from Nebraska named “Beauty.” The manager bought the cow because she produced a lot of milk, but she was also pregnant. Her calf, they named “Chief” and he was quite special. 

The young bull had an enormous appetite, fierce strength, a broad chest, a large muzzle and a thick body, all sought-after traits. The farm used Chief to breed, and that’s when they noticed something magical: His daughters — who had wide rumps and udders — produced huge quantities of milk. Chief’s daughters also began producing milk at a very young age and in such large amounts that many believed it wouldn’t last. 

The farm then started leasing out Chief for breeding and his daughters began to appear around the country. It’s said that Chief’s daughter “Beecher Arlinda Ellen” produced 55,600 pounds of milk in her life, a world record that stood for more than a decade. His sons were strong and virile; many ranked among the world’s top studs. Over the course of his life, Chief produced enough sperm to yield more than 16,000 daughters, and he has more than 500,000 granddaughters and 2 million great-granddaughters. In all, 14% of American dairy cattle can trace their lineage back to Chief. 

However, the story doesn’t stop there. Decades after Chief passed, breeders noticed that the miracle bull wasn’t perfect. When two animals in his line bred with one another, some cows would spontaneously abort fetuses at elevated rates. A team of USDA researchers eventually tracked this abortive variant back to Chief (study was published in the current issue of the Journal of Dairy Science). The mutation would prove responsible for more than half a million spontaneous abortions in dairy cattle worldwide, which cost the industry an estimated $420 million. That’s a large figure, but you could say it pales in comparison to the estimated $30 billion in income Chief’s genes have churned for dairy farmers around the world over the past 50 years.

Through advances in genetics, the USDA and scientists at the University of California, Davis were able to identify the exact source of the mutation. They were then able to develop a test that identified cattle that might be carriers. Already, the frequency of cattle carrying this trait has been reduced to 2%. But with the new test, that percentage could one day reach zero. Problematic traits can be removed by not letting carriers breed. 

This story illustrates just how the dairy industry is one of the most advanced areas of agriculture, in terms of incorporating genetics. All bull semen is tested for a variety of genetic defects, so problematic traits can be isolated and good ones can be recognized even before a bull has offspring. But sometimes, as in Chief’s case, it takes years to unravel the good from the bad. (Source: The Atlantic)

1 thought on “How One Bull Passed On A Deadly Gene to 14% of U.S. Dairy Cows”

  1. The bull created amazing calves and other stud bulls. after awhile they found out that his offspring were having higher abortion rates. His calves created amazing milk production which helped farmers make more money.

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