The document summarizes genetic improvement efforts over 60 years at the One Bar Eleven Ranch in Wyoming. Key traits under selection include growth (birth weight, weaning weight, yearling weight), calving ease, maternal ability, and pulmonary arterial pressure (PAP) as a measure of tolerance to high altitudes. Genetic trends show increases in growth, maternal traits like milk production, and decreases in PAP and improvements in calving ease and longevity. Current research uses genomic technology to identify genes associated with complex traits like PAP to further improve selection accuracy and generate DNA-enhanced breeding values.

1. Genetic Improvement at Beef Improvement Center/One Bar Eleven Ranch
A. O. Fritts, R. R. Cockrum, S.E. Speidel, R. M. Enns, M. G. Thomas
Colorado State University Beef Improvement Center, Department of Animal Sciences, Fort Collins, CO
Introduction
The objective of this study was to determine the genetic progress of the One Bar Eleven
Ranch over the past 60 years. Trends analyzed focused on growth characteristics, birth
weight, weaning weight, yearling weight, and milk, (BW, WW, YW, and Milk, respectively),
calving ease direct, calving ease total maternal, and stayability (CED, CETM, and STAY,
respectively), and tolerance to high altitude as measured through pulmonary arterial
pressure (PAP). Elevated PAP measurements have been selected against to reduce the
incidence of animals developing High-Altitude Disease or Brisket Disease. Trends in relation
to growth and stayability have been selected to enhance the progeny performance in feed
efficiency and female longevity . Calving ease has focused on decreasing death losses
associated with dystocia and delayed rebreeding of the cow.
HISTORY
In 1986, John E. Rouse, a long-time cattleman and oil company executive, donated his Angus
ranch located in Saratoga, Wyoming to Colorado State University (CSU) Department of Animal
Sciences to improve agricultural education and conduct beef cattle breeding research. In
2009, the Rouse family purchased the ranch back from CSU. An endowment fund was then
established at CSU with the proceeds of the endowment to supplement ranch operations,
fund continued research and establish the John E. Rouse faculty chair in the Department of
Animal Sciences. Current research at One Bar Eleven has focused on 1) improving growth and
carcass characteristics, stayability (cow longevity) and adaptability, and 2) incorporating
genomic technology to study and select cattle tolerant to high elevations.
Herd Management
RESULTS
Sire selection
• Traits desired
- Growth (birth weight, weaning weight, yearling weight)
- Calving ease (Direct and Maternal)
- Maternal ability (Milk and Stayability)
- Pulmonary arterial pressure (PAP):
- Calves tested as yearlings
- Sire selection typically < 40 mmHg and no bull with PAP > 55 mmHg sold
- Average bulls in sale = PAP ± 46.3 mmHg
• ~60 bulls with desired traits (e.g., growth, stayability, and PAP) are placed on test
• Remaining bulls are castrated and sent to a “Carcass and Feed Efficiency” program at CSU’s
Agriculture, Research and Development Center (ADREC) located in Fort Collins, Co and
ultimately finished at the CSU Eastern Colorado Research Center, Akron, CO
• > 85% of One Bar Eleven steers grade choice in the last 3 years with last year’s steers
grading > 90% choice
Undesired
Traits
Desired Traits
Maternal
Traits
Growth &
Carcass
Low PAP
High-Altitude
Disease
Decrease in
Growth
Dystocia
Figure 1: Milk, yearling weight (YW) and
weaning weight (WW) have shown steady
increases in genetic progress, while birth weight
(BW) has remained low.
-40
0
40
80
AverageEPD(lbs)
Birth Year
American Angus Association
Genetic Trend for Growth Traits
YW CW MW Milk
Glossary Terms and Abbreviations Conclusions and Future Research
• Birth Weight, Weaning Weight and Yearling Weight EPD: Expressed in pounds, it is a predictor of
difference in sires’ progeny due to differences in breeding value for the trait of interest.
• Calving Ease EPD (CE): Expressed as a probability of an unassisted birth, it is a predictor of a sire’s ability
to produce calves born unassisted. Higher values represent easier calving, CE Total Maternal represents
the ability of a sire’s daughters to calve easily.
• Milk EPD: Expressed in pounds of calf weaned it is the difference in performance expected from
daughters of the bull in question due to differences in genetics for milk production.
• PAP: (Pulmonary Arterial Pressure) Obtained by a procedure called “right heart catheterization”, this test
is the best indicator to date for identifying animals predisposed to Brisket Disease. The test is not 100
percent accurate and should be used with that knowledge. Generally, cattle with PAP values greater than
50 are considered high risk and cattlemen should be cautious of using them at high elevations.
• Stayability EPD (STAY): The probability that a sire’s daughters will remain in the herd to age six assuming
they produced their first calf at 2 years of age. This trait represents longevity of a sire’s daughters.
(Higher values result in a greater probability that a sire’s daughters will remain in the herd to 6 years of
age.).
Figure 2: The American Angus Association have
shown similar genetic trends as Rouse Angus in
yearling weight (YW), carcass weight (CW),
mature weight (MW) and Milk breeding values.
Figure 3: Stayability has increased while calving
ease (CED and CETM) show a decline suggests
cows are staying within the herd longer while
needing less assistance when calving.
Although genetic trends have suggested improvements in growth, maternal traits, and
average PAP in the One Bar Eleven herd, there is still enormous room for genetic
improvements. Introduction of the bovine genome sequence in 2004 has enhanced the
industries base understanding of the relationship between environmental factors and gene
interaction. The Breeding and Genetics team at Colorado State University are currently using
whole-genome technology to identify the underlying mechanisms associated with complex
traits like PAP. To date, ~1750 cattle in the One Bar Eleven herd have been genotyped.
Additionally, this summer ~20 steers from the herd will have their whole genome sequenced
to determine gene expression patterns. Collaborations with One Bar Eleven Ranch, CSU, and
the University of Colorado Anschutz Medical School are using cutting edge technology to
further understand difficult traits that will be used to improve the accuracy of selection. To
translate these scientific findings, the long-term goal is to generate a genome (i.e., DNA)-
enhanced EPD. Please follow our research briefs to stay updated.
1960 1970 1980 1990 2000 2010
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Birth Year
Probability
One Bar Eleven Ranch Calving Ease Direct,
Calving Ease Total Maternal, and Stayability EPD Genetic Trend
Calving Ease Direct EPD
Calving Ease Total Maternal EPD
Stayability
1960 1970 1980 1990 2000 2010
010203040
Birth Year
AverageEPD(lbs)
One Bar Eleven Ranch Birth, Weaning,
and Yearling Weight and Milk EPD Genetic Trends
Milk EPD
Birth Weight EPD
Weaning Weight EPD
Yearling Weight EPD
Figure 4: Pulmonary Arterial Pressure (PAP)
continues to trend downward given cattle with
PAP > 55 mmHg are selected against.
October 1
Calves weaned,
vaccinated, genotyped,
and measured for PAP
April 10
Determine AI
Sires and
mating
May 6
Synchronize yearling
heifers
May 15
AI yearling
heifers
June 6
Synchronize
Cows
June 17
AI cows
June 30
Clean up
bulls go out
July 30
Ultrasound cows
and heifers
February 15
Beginning of calving
season
May 1
End of calving
October 1
Bull calves with PAP > 55 mmHg
castrated and placed in “Carcass
and Feed Efficiency” program
March 15
PAP test bulls for
Rouse bull sale
April 8
Rouse Bull Sale
2011 2012 2013
1960 1970 1980 1990 2000 2010
-1.0-0.50.00.51.0
Birth Year
AverageEPD(mmHg)
One Bar Eleven Ranch PAP EPD Genetic Trend
PAP EPD