Cattle losing adaptations to environment
Researchers pave the way for genetic tests of cattle that can look for
the presence of specific adaptations, such as heat resistance

Date:
July 22, 2021
Source:
University of Missouri-Columbia
Summary:
Researchers have uncovered evidence showing that cattle
are losing important environmental adaptations, losses the
researchers attribute to a lack of genetic information available
to farmers. After examining genetic material stretching back to
the 1960s, they identified specific DNA variations associated
with adaptations that could one day be used to create DNA tests
for cattle -- tests that could tell farmers whether their cattle
are suited for one environment or another.



FULL STORY ==========================================================================
As a fourth-generation cattle farmer, Jared Decker knows that cattle
suffer from health and productivity issues when they are taken from
one environment - - which the herd has spent generations adapting to
-- to a place with a different climate, a different elevation or even
different grass. But as a researcher at the University of Missouri,
Decker also sees an opportunity to use science to solve this problem,
both to improve the welfare of cattle and to plug a leak in a nearly
$50 billion industry in the U.S.


========================================================================== "When I joined MU in 2013, I moved cattle from a family farm in New
Mexico to my farm here in Missouri," said Decker, an associate professor
and Wurdack Chair in Animal Genetics at the College of Agriculture,
Food and Natural Resources. "New Mexico is hot and dry, and Missouri is
also hot but has much more humidity. The cattle certainly didn't do as
well as they did in New Mexico, and that spurred me to think about how
we could give farmers more information about what their animals need
to thrive." In a new study published today in PLOS Genetics, Decker
and his team have uncovered evidence showing that cattle are losing
important environmental adaptations, losses the researchers attribute
to a lack of genetic information available to farmers. After examining
genetic material stretching back to the 1960s, they identified specific
DNA variations associated with adaptations that could one day be used
to create DNA tests for cattle -- tests that could tell farmers whether
their cattle are suited for one environment or another.

"We can see that, for example, historically cows in Colorado are likely to
have adaptations that ease the stress on their hearts at high altitudes," Decker said. "But if you bring in bulls or semen from a different
environment, the frequency of those beneficial adaptations is going
to decrease. Over generations, that cow herd will lose advantages that
would have been very useful to a farmer in Colorado." Decker's team,
including then-doctoral student Troy Rowan, analyzed six decades worth
of bovine DNA data from tests of cryo-preserved semen produced by cattle
breed associations. They found that over time, while genes associated
with higher productivity and fertility improved due to careful selection
by farmers, many genes connected to environmental adaptations have faded.

Decker noted this is not the fault of farmers, given that there is
currently no cost-effective genetic test they can use to determine
whether their cattle are suitable for a particular environment. In
other words, the study demonstrates a need for user-friendly cattle
DNA tests that can look for the specific adaptations identified in the
study. These adaptations include resistance to vasoconstriction -- a
narrowing of the blood vessels that occurs at high elevations and puts
undue stress on the heart -- resistance to a toxin in grass that can
also cause vasoconstriction, and tolerance for high heat or humidity,
all of which tend to recede over generations when cattle are removed
from the associated environments.

"Sometimes, natural and artificial selection are moving in the same
direction, and other times there is a tug of war between them," Decker
said. "Efficiency and productivity have vastly improved in the last 60
years, but environmental stressors are never going to go away. Farmers
need to know more about the genetic makeup of their herd, not only for
the short-term success of their farm, but for the success of future generations." The first broadly adopted genetic test for cattle was
invented at the University of Missouri in 2007, and Decker and Rowan hope
to tell the next chapter of that story. Both grew up on farms and share
a passion for using research to help farmers balance America's farming traditions with the need for environmentally friendly business practices.

"As a society, we must produce food more sustainably and be good
environmental stewards," Decker said. "Making sure a cow's genetics
match their environment makes life better for cattle and helps
farmers run efficient and productive operations. It's a win-win." ========================================================================== Story Source: Materials provided by University_of_Missouri-Columbia. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Troy N. Rowan, Harly J. Durbin, Christopher M. Seabury, Robert D.

Schnabel, Jared E. Decker. Powerful detection of polygenic selection
and evidence of environmental adaptation in US beef cattle. PLOS
Genetics, 2021; 17 (7): e1009652 DOI: 10.1371/journal.pgen.1009652 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/07/210722162957.htm

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