Beef Improvement Federation
Identifying the Hill Climber and Bottom Dwellers
By Megan Silveira
“Cattle are not like lawnmowers.”
While Derek Bailey’s opening statement
during his presentation, “Development
of Grazing Distribution Phenotypes,”
during the Beef Improvement
Federation Research Symposium and
Convention in Loveland, Colo., might
have drawn a few chuckles, cattlemen
cannot deny the truth in his statement.
The lives of cattlemen would
undoubtedly be made easier if cattle
were like lawnmowers, consuming
everything in an area in an even,
consistent manner. Unfortunately,
this is not reality, he said.
Bailey said in the western region of the
United States, where cattle are raised
on rangeland, grazing distribution
has recently become a hot topic.
Cattle are selective grazers, choosing
to graze areas with higher biomass
and greater nutrients while avoiding
areas with toxins, steep slopes and
areas at greater distance from water.
By avoiding certain areas, Bailey
explained, livestock miss potential
nutrients available from the
land. Approximately one-third of
many rangelands have grazeable
areas that are not used.
“Grazing distribution has value,”
Bailey said. “If you can get cattle
20 | AUGUST 2018
to travel from water, you have
more grazing opportunities.”
Bailey has been studying cattle in order
to see where cows graze and why. He
said grazing distribution is a “difficult
and expensive trait to measure.” Data on
the topic is difficult to condense, as it
is so vast. He has narrowed the focus of
his studies to terrain instead of diet to
better understand grazing distribution.
He said terrain use is multi-dimensional.
For his studies, Bailey integrated
terrain attributes, normalizing slope,
elevation and distance to water in
the data he collected so the value for
the average cow would equal 100.
Bailey created two indices, a rough
index including slope and elevation
and a rolling index including slope,
elevation and distance to water.
Bailey found cattle often fall into
one of two categories in regard to
grazing distribution. Cows will either
be “bottom dwellers” that choose to
eat grass available on flat ground or
“hill climbers” willing to explore the
rolling hills to find their next meal.
Bailey said he could find no
phenotypical relationship between
performance and terrain use in these
females. He was, however, interested
in the fact that even when these
two groups of cattle were separated
— eliminating the possibility that
dominant cattle pushed others out
of their desired area — they kept
their particular grazing habit.
“I think there’s a heritable component
to it,” Bailey said. While the age-old
question of “nature or nurture” has not
yet been solved in regard to grazing
distribution, Bailey said this will be a
focus for their upcoming studies.
With all this new data available about
grazing distribution, Bailey is eager
to provide ranchers with a way to use
this information to their advantage.
“Even though it’s a complex trait, I think
there’s still some potential,” Bailey said.
“Instead of trying to mess with all the
hassle, if we could create a genomic
EPD, that could change everything.”
Bailey’s surveys have led him to believe
ranchers are willing to pay for tests
tracking animals’ grazing movements to
use this data to their advantage. While
the knowledge ranchers and researchers
possess about grazing distribution
is constantly growing, Bailey said he
believes this trait has the ability to
revolutionize the cattle industry. I
This article is reprinted with permission
from www.BIFconference.com, Angus
Media’s online coverage site of the 2018
Beef Improvement Federation Research
Symposium and Annual Meeting.