Iowa State vet college received a grant to study calf diseases (in hopes of developing DNA tests to enable gene therapies, replacing antibiotics being banned from food animals). After 11,000 DNA samplings on sick calves and their healthy herdmates, they found a marker gene appearing to prevent debilitating scours from Salmonella and E-Coli infections. Of interest was this gene is linked to the recessive Red hair color gene… thus suggesting that the feeder market fixation with Black cattle (hoping to ride on the success of “certified Angus beef”) may begin to change. Iowa State has licensed this discovery to a company that will test your cattle for the marker.
The big debate that is arising from all the use of DNA testing in both Beef and Dairy cattle, is does DNA testing replace Genetic selection, which is based on trait measurement and behavior observation? Advocates of DNA tests claim animals can be culled after birth just on genotype characteristics, and faster breeding progress made from a reduced gene pool of animals with an “ideal” genotype. Critics of DNA selection point out that focusing only on a single genotype is a sure path for accumulating “inbreeding depression”. They further note that we do not make our livings from the genotype, but from the phenotype (the living result that grows up and has adapted to our individual environment).
The latest area of genetic exploration is “epigenetics” which documents how any sustained change in the environment alters the functions of genes. And the environment will always be changing— starting with nutritional choices, and genetic changes in the feed themselves.
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