1. Teat and Udder Score EPDs
Heather Bradford
University of Georgia

2. Acknowledgments Kansas State University Shane Bedwell, AHA
Ryan Boldt, CSU
Larry Keenan, RAAA

3. Importance for the Cow Longevity Mastitis 2.7 % of cull cows
Especially older cows
Mastitis
Weak suspension
Decreases WW by up to 50 lbs
Dueñas et al., 2001; DeGroot et al., 2002; Lents et al., 2002; Rupp and Boichard, 2003; USDA, 2010

4. Importance for the Calf
Labor
Assisting calves to suckle
Pendulous suspension, extreme teat sizes
Mortality
Later colostrum consumption
Long or large diameter teats
Growth
Smaller teats and udders
Wythe, 1970; Edwards, 1982; Frisch, 1982; Ventorp and Michanek, 1992; Goonewardene et al., 2003

5. Measurement Subjective scores 1 to 9 24 hours after calving
Poorest quality quarter
Evaluated by same person within a herd
Ranking of cows more important than actual score
BIF Guidelines, 2010

6. Measurement at AHA Historically 1 trait recorded (overall score)
BIF recommends recording 2 traits in July 2008
Change to 2 traits in August 2008
Udder suspension (UDDR)
Teat size (TEAT)

7. Overall Score 9 8 7 6 5 4 3 2 1
Denton, 2007

8. BIF Guidelines, 2010

9. Research History American Gelbvieh Association, 2001
Sapp et al., 2004 (doi: / x)
American Hereford Association, 2012
Bradford et al., 2015 (doi: /jas )
Red Angus Association of America, 2017
Boldt et al., in progress

10. Descriptive Statistics
Trait
Mean SD N
Hereford
Suspension
7.16
1.42
266,283
Teat size
6.98
1.48
266,393
Overall score
7.23
1.50
303,112
Red Angus
6.05
1.68
48,730
6.10
1.66
48,704

11. Distribution of Scores
Pendulous suspension
Large teats
Tight suspension
Small teats

12. Model Overall Score Udder Suspension Teat Size Genetic Evaluation
Udder Suspension EPDs
Teat Size EPDs

13. Model Multiple-trait animal model Random effects Fixed effects
Additive genetic
Permanent environment
Fixed effects
Contemporary group (herd-year-season)
Age

14. MacNeil and Mott, 2006; Boldt et al., unpublished
Repeatability
L1 Hereford repeatability = 0.34
Red Angus repeatability ~ 0.30
Trait
Repeatability
Overall Score
0.49 (0.004)
Udder Suspension
0.49 (0.010)
Teat Size
0.47 (0.005)
MacNeil and Mott, 2006; Boldt et al., unpublished

15. Records per Cow

16. Boldt et al., unpublished
Heritability
Red Angus
Suspension h2 = 0.32
Teat size h2 = 0.28
Trait h2
Overall score
0.32 (0.01)
Suspension
0.31 (0.01)
Teat size
0.28 (0.01)
Boldt et al., unpublished

17. Sapp et al., 2004; Boldt et al., unpublished
Genetic Correlations
Udder suspension and teat size
Gelbvieh r = 0.95
Red Angus r = 0.80
Overall score
Suspension
0.70 (0.02)
Teat size
0.72 (0.02)
0.83 (0.01)
Sapp et al., 2004; Boldt et al., unpublished

18. Implementation 2013 research EPDs on proven bulls Spring 2015 US
Fall 2017 US and Canada
Coming soon GE-EPDs

19. EPDs
Udder Suspension Teat Size
Larger EPD
Smaller EPD

20. Udder Suspension (UDDR)
EPDs
Bull
Udder Suspension (UDDR)
Teat Size (TEAT) A
1.50
0.75 B
0.50
1.25
Avg
1.16
1.17
Expect Bull A’s daughters to be 1 score tighter for suspension
Expect Bull B’s daughters to be 0.5 score smaller for teat size

21. Increased Reporting
Research
EPD
AHA, 2017

22. Genetic Trends Tight suspension Small teats Loose suspension
Large teats
AHA, 2017

23. Correlations with Other Traits
Udder and Milk moderately negative
More milk = more udder problems
Udder and WW negative to positive
More growth = ?
Reproductive and longevity traits?
Sapp et al., 2004; MacNeil and Mott, 2006

24. Challenges Contemporary groups with no variation
AHA
RAAA ~ 50% (Boldt et al.)
Same score for both traits
Multiple-trait selection

25. Conclusions Moderately heritable Selection for intermediate optimum
More records per cow, greater accuracy
Improved education on scoring system