1. Reproductive Tract Scoring
Brendan Kraus, DVM

2. Heifer Selection Most Cattleman Select Visually
Use Size and Appearance
Cannot evaluate reproductive traits externally

3. Age at Puberty Defined as the age of first behavioral estrus (heat)
Age of puberty is highly associated with
Pregnancy Percentage
Percent calving in first 25 days
Milk production
Heavier progeny weaning weights

4. Early Conception is the Name of the Game
Early calving heifers have higher annual lifetime calf production
Are more likely to conceive and calve as 3 year olds
Wean a bigger calf
Can’t afford to have heifers and 2nd calf heifers drop out of the program

5. Reproductive Tract Scoring
RTS system estimates pubertal status via rectal palpation of the uterine horns and ovaries
RTS 1: Infantile tracts
RTS 2: Small uterine horns and ovaries
RTS 3: Slight uterine tone
RTS 4: Good uterine tone, functional ovaries
RTS 5: RTS 4 + palpable corpus luteum

6. Bovine Reproductive Tract

7. Bovine Repro Tract

8. Bovine Ovaries

9. When to Perform RTS?
The distribution of RTS for a group of heifers depends on when they are examined
If before 12 months of age, most heifers will not be cycling
If taken too late, most will receive a 4 or 5
The time of exam depends on the desired use of the system and the particular group of heifers

10. For Instance, Last minute culling tool
Scoring should occur a month or less before breeding. Immature heifers are culled
Selection pressure for age at puberty
Evaluate when ½ of heifers are cycling based on age, weight, and estrus observation
Heifer development check-up
30 to 60 days prior to breeding. Nutritional ration can be adjusted according to findings

11. RTS 3 vs 4
Heifers scoring 3 at 30 days prior to breeding have up to 20% more opens than heifers scoring 4 or 5
There is considerable expense developing heifers from weaning to pregnancy exam. It is very costly to have them turn up open at this stage

12. Effects on RTS Age of Heifer Sire genetics Weight/Condition Score
Scrotal size
Weight/Condition Score
Inbreeding

13. Other Strategies Breed heifers one month before the cow herd
Minimally develop heifers and use RTS as a tool to select for inherent fertility and lower maintenance cows

14. Prepare for Breeding MLV vaccine for IBR/BVD Vibrio/Lepto
7-Way Clostridial
Deworm
Brand/Ear Tag
Pelvic Measure

15. Pelvic Measure
Used as a tool to eliminate small pelvis or those with abnormal shape
Used in conjunction with RTS
Is not used to select for largest pelvic
Utilizes a formula which considers age, weight, and size of calf to deliver
Has been shown to allow heifers to deliver 80% unassisted

16. Questions?
* “The Use of Reproductive Tract Scoring in Beef Heifers” Anderson et al CSU Dept of Animal Sciences. Agri-Practice 1991