Transcript Reproductive Tract Scoring

Reproductive Tract
Scoring
Brendan Kraus, DVM
Heifer Selection
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Most Cattleman Select Visually
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Use Size and Appearance
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Cannot evaluate reproductive traits externally
Age at Puberty
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Defined as the age of first behavioral estrus
(heat)
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Age of puberty is highly associated with
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Pregnancy Percentage
Percent calving in first 25 days
Milk production
Heavier progeny weaning weights
Early Conception is the Name of the
Game
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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
Reproductive Tract Scoring
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RTS system estimates pubertal status via rectal
palpation of the uterine horns and ovaries
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RTS 1:
RTS 2:
RTS 3:
RTS 4:
RTS 5:
Infantile tracts
Small uterine horns and ovaries
Slight uterine tone
Good uterine tone, functional ovaries
RTS 4 + palpable corpus luteum
Bovine Reproductive Tract
Bovine Repro Tract
Bovine Ovaries
When to Perform RTS?
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The distribution of RTS for a group of heifers
depends on when they are examined
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If before 12 months of age, most heifers will not
be cycling
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If taken too late, most will receive a 4 or 5
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The time of exam depends on the desired use of
the system and the particular group of heifers
For Instance,
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Last minute culling tool
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Selection pressure for age at puberty
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Scoring should occur a month or less before
breeding. Immature heifers are culled
Evaluate when ½ of heifers are cycling based on
age, weight, and estrus observation
Heifer development check-up
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30 to 60 days prior to breeding. Nutritional ration
can be adjusted according to findings
RTS 3 vs 4
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Heifers scoring 3 at 30 days prior to breeding
have up to 20% more opens than heifers
scoring 4 or 5
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There is considerable expense developing heifers
from weaning to pregnancy exam. It is very costly
to have them turn up open at this stage
Effects on RTS
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Age of Heifer
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Sire genetics
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Scrotal size
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Weight/Condition Score
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Inbreeding
Other Strategies
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Breed heifers one month before the cow herd
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Minimally develop heifers and use RTS as a
tool to select for inherent fertility and lower
maintenance cows
Prepare for Breeding
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MLV vaccine for IBR/BVD
Vibrio/Lepto
7-Way Clostridial
Deworm
Brand/Ear Tag
Pelvic Measure
Pelvic Measure
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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
Questions?
* “The Use of Reproductive Tract Scoring in Beef Heifers”
Anderson et al CSU Dept of Animal Sciences. Agri-Practice
1991