This document summarizes a research study on beef cattle selection and management for drought adaptation. The study involves monitoring the feed and water intake of 840 beef cattle over 70 days to establish baseline consumption. It then restricts water intake over 35 days to simulate drought while continuing to monitor intake, weight gain, behavior, and health. The goal is to identify cattle that are more efficient with limited water and develop selection and management tools for drought adaptation. Results will help beef producers maintain the long-term sustainability and viability of their operations in the face of climate change challenges.

1. Beef Cattle Selection and
Management for Adaptation to
Drought
Megan Rolf
State Beef Extension Specialist
Oklahoma State University

2. Available precipitation (difference between monthly precipitation and potential
evapotranspiration [PET], sum of months with nonzero values) for the
conterminous United States. (Source: USGS Circular 1323; Ne.water.usgs.com)

3. Figures from Agcensus.usda.gov and Ne.water.usgs.com

4. Beef Cattle Water Intake
 Consume 760 Billion L per year (Beckett and Oltjen,
1993)
 Influenced by physiological and environmental
parameters
 Size/weight (i.e. Brody et al. 1954; Ittner et al.
1951,1954)
 DMI (Ritzman and Bendict 1924; Leitch and Thompson,
1944)
 Ambient temperature and solar radiation (Mader and
Davis 2004; Amundson et al. 2006; Mader et al. 2006)
 Sexson et al. 2012 estimated individual WI from
environmental data utilizing 8,000 pen records
 R2=0.32
 Significant individual animal variation

5. Water
 Consumptive water use in the beef industry
 Not as important on a LCA scale
 Irrigation of pre-harvest water and feed ~95%
 Underscores importance of feed efficiency
 Critical for an individual farmer

6.  Decreased water availability
 Amplified by increased evaporation if hot
 Decreased water quality from increase in
adulterants
 May affect taste and odor, palatability (Lardner
et al. 2005)
 Decreased performance likely due to reduced
water and feed intakes (Lardner et al. 2005)
 Increased water temperature
 Typically increase water demand
 Particularly apparent in taurine cattle (Ittner et
al. 1951)
 Need to consume more water, when we have
less available and they are less likely to want
to drink it
 Water restriction
 Increases the spread of maximum and minimum
body temperatures (interferes with body
temperature regulation; Finch 1985)
What to Expect During Drought
J. Anim. Sci Vol. 62 No. 2, p. 531-542
Australian Journal of Agricultural Research. 56: 97–104

7. Project Overview
 5 year integrated USDA project
 Climate change and mitigation RFA
 Adaptability to abiotic stresses
 Water availability and quality, temperature-related
stresses
 Includes research and extension components
 Goal: Develop beef cattle selection and
management tools that address
conservation of water resources and
adaptation to climate variability (drought)

8. Insentec System
 21 Day acclimation period
 Commence test protocol

9. Study Design
 70 day baseline feed and water intake test
 Individual animal (n=840, n=120 each round)
 Water intake
 Feed intake
 Periodic weights (ADG)
 Behavioral data (temperament, posture, social interactions,
shade use, motion index, etc.)
 Health status (blood cell counts, treatment data for health
interventions, electrolyte balance, hematocrit, etc.)
 Heat stress measures (respiration rates, subset with rumen
boluses)
 Cold stress measures (behavioral data)
 Rumen and fecal samples
 Pedometers on a subset of animals in each pen

10. Study Design
 70 day adaptation test
 Every animal serves as its own control
 35 day step-down phase
 Water intake restricted by 10% each week until reach 50%
of baseline
 35 day extended water restriction period
 Maintained at 50% of normal intake for 5 weeks
 Feed intake
 Periodic weights (ADG)
 Behavioral data (temperament, posture, social interactions, shade
use, motion index, etc.)
 Health status (blood cell counts, treatment data for health
interventions, electrolyte balance, hematocrit, etc.)
 Heat stress measures (respiration rates, subset with rumen
boluses)
 Cold stress measures (behavioral data)
 Rumen and fecal samples
 Pedometers on a subset of animals

11. Study Design
 Feed samples (high roughage)
 Analyzed for dry matter weekly
 Stored for future nutrient analysis
 Water Samples (TCFA)
 Water quality monitored once/month throughout the
study
 Tested in on-campus water lab
 Calves maintained in the feedlot through finishing
phase
 Impacts on carcass performance
 140 control steers (20 in each group)
 Collection of tissues at harvest (where possible)

12. Summary Statistics

13. Summary Statistics (Cont.)
Number of
Animals
Mean Restriction
Level*
Feed Intake
Reduction
Average Daily
Gain Reduction
Low Water Intake
Group
39 53%ac 22%c 30%d
Medium Water
Intake Group
39 55%ab 19%c 22%de
High Water Intake
Group
39 52%ac 17%c 19%e

14. Results
y = 1.5076x + 0.0729
R² = 0.0756
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.005 0.01 0.015 0.02 0.025 0.03
WaterIntake(as%ofmid-testbodyweight)
Feed Intake (as % of mid-test body weight)
Ad-libitum feed intake and water intake
Figure 1: Graph of ad-libitum water and feed intake expressed as a percentage of mid-test body
weight (to correct for bias due to body size) for steers in group 1 (n=117) over a 70 day feed and water
intake test.

15. y = -0.0004x + 0.102
R² = 7E-05
0.00
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.0 0.5 1.0 1.5 2.0 2.5
WaterIntake(as%ofmid-testbodyweight)
Mean Average Daily Gain (kg)
Ad-libitum Water Intake and Average Daily Gain
Results

16. More Still to Come!
 6 more rounds of calves (Group 2 will move to finishing April 1 2015)
 70K genotyping data (GGP-HD)
 Water intake and efficiency
 Feed efficiency
 Adaptability to abiotic stresses
 Heritability estimates and GWAS for these traits
 WI highly heritable in laboratory animals (~70%)
 Other traits with data collected
 Metagenomic sequencing
 How is the rumen affected by water quality and availability?
 >60% of protein requirement generated by microbes (Church 1993)
 10 high and 10 low water intakes
 10 most and 10 least adaptable
 Rumen and fecal samples before and during water restriction
 GHG emissions predictions through modeling
 Tissue collections and GHG emissions data (head boxes)?

17. Extension Outcomes
Long-term business viability, stewardship of natural resources,
and responsibility to community, family, and animals
Economic
Environment Social
Focus on
Sustainability

18. Extension Outcomes
 Evaluation of consumer perceptions on
beef production sustainability and natural
resource usage
 Provide consumer education to fill knowledge
gaps and misconceptions
 Online educational modules

19. Tools for Producers
 Cattle water demand tool
 Expansion of the cattle comfort advisor

20. Extension Outcomes
Long-term business viability, stewardship of natural resources,
and responsibility to community, family, and animals
Economic
Environment Social
Focus on
Sustainability
Cattle comfort advisor:
Reduce economic losses due
to not planning for heat stress
Water Demand
Tool:
Manage on-farm
natural resources
Surveys:
Assess consumer
attitudes towards
sustainability and
natural resource usage
Cattle comfort advisor:
Animal well-being

21. Project Team
Oklahoma State University
Megan Rolf
Michelle Calvo-Lorenzo
Sara Place
Chris Richards
Clint Krehbiel
Udaya DeSilva
University of Florida
Raluca Mateescu
Collaborators
DL Step-OSU Center for Veterinary
Health Sciences
Al Sutherland-Oklahoma
Mesonet
This project was supported by Agriculture and Food
Research Initiative Competitive Grant no. 2014-
67004-21624 from the USDA National Institute of
Food and Agriculture.

22. Graduate Students
 Rolf Lab
 Cashley Ahlberg
 Kristi Allwardt
 Ashley Broocks
 Justin Buchanan
 Kimberly Branham
 Others
 Catherine Haviland
 Jake Reed
 Justin Lyles
 Emily Andreini
 Andrew Grimes

23. Thank you!
http://www.ansi.okstate.edu/research/labs/genetics/rolf/home