For genetic evaluation and contemporary group ratios, weaning weights are standardized to a calf age of 205 days and a
mature dam equivalent. Breed-specific nonlinear equations are used to adjust calf weights to a common age.
This allows fair,
age-equivalent comparisons among calves weaned between 120-280 days. The lower minimum acceptable weaning age of 120 days provides
flexibility to breeders in weaning dates, along with allowing younger calves to remain in their respective contemporary groups for
National Cattle Evaluation.
Weaning Age of Dam Adjustment Chart
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If Age-of-dam (at 205) is
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Add Lbs. to Age Adjusted Weaning Weight
|
|
MALE
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FEMALE
|
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thru 2 yrs. 243 days
|
68
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57
|
|
2 yrs. 244 days thru 3 yrs. 91 days
|
67
|
55
|
|
3 yrs. 92 days thru 3 yrs. 273 days
|
37
|
32
|
|
3 yrs. 274 days thru 4 yrs. 91 days
|
29
|
21
|
|
4 yrs. 92 days thru 5 yrs. 91 days
|
15
|
13
|
|
5 yrs. 92 days thru 10 yrs. 91 days
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0
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0
|
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10 yrs. 92 days and older
|
22
|
19
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= (actual yearling wt - actual weaning wt) x 160 + 205-day adj. weaning wt
No. of days between measure ages
Example
Actual yearling weight 1085 lb yearling measure age
363 days
Actual weaning weight 660 lb weaning measure
age 209 days
205-adjusted weaning weight 731 lb
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Adjusted 365-d Yearling Weight =
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(1085 - 660)
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x 160
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+ 731
|
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(363-209)
|
|
|
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=1173 lb
|
|
|
Considerations
Adjusted 365-day weights are computed to adjust an actual yearling weight taken
by the breeder to a standard animal age (365-day, typically) and age of dam (this
adjustment takes place through the use of the 205-d weaning weight). Acceptable
calf ages for yearling measures are 320-440 days of age.
The suggested period between weaning and yearling weight is 160 days. A common mistake
is that the two weights are taken too closely together. Although the window of acceptable
weaning weight ages is 120 to 280, and yearling wt age 320 to 440 days of age, you
need to try to allow for more postweaning gain growth time to better characterize
the trait.
Weight per Day of Age (WDA)
Many times, weight per day of age (WDA) calculations provide a source of confusion.
In contrast to the 365-day yearling weight, the WDA is calculated as follows:
WDA = Actual weight/days of age
In the above example using weaning weight as the actual weight taken, WDA= 660/209
= 3.16 lb per day of age
Docility Scores
The scores provided are designed to evaluate disposition differences when processing animals through the chute.
Scores should be an observation of how animals enter, exit and react while being handled in the chute.
Docility may be reported on:
1. Cows when they wean their calves
2. Calves when yearling data is reported
3. Calves when weaning data is reported
1 Docile
Acceptable, mild disposition, most favorable temperament.
2 Restless
Restless during processing.
3 Nervous
Nervous and impatient.
4 Flighty (Wild)
Jumpy and out of control, quivers and struggles violently.
5 Aggressive
Added aggressive behavior, extreme agitation.
6 Very Aggressive
Extremely aggressive temperament.
Foot Scoring
Proper foot structure is essential to an animal’s longevity, and Angus is leading the U.S cattle industry in assessing an issue pertinent to
all breeds – structural soundness. The American Angus Association accepts foot scores from its member through a simple recording system using
two categories, foot scores and claw set on a 1 – 9 scale where a score of 5 would be ideal. Foot scores on bulls and females
should be collected during yearling data collection. Older females can be scored using those same guidelines when collecting mature cow weights. Large
group data on 18-month or 2-year-old bulls can also be submitted. For more information on the individual 1-9 scores
.
Ultrasound
These ultrasound images are collected by a UGC certified field technician between 320 and 440 days of age for bulls and 320 and 460 days for heifers.
Weaning weights submitted prior to the scanning date are required to process ultrasound data. The ultrasound field technician sends the images to
one of the American Angus Association's authorized ultrasound processing labs for interpretation by a UGC certified lab technician, along with the
barnsheet generated when weaning weights are submitted. If you do not have a barnsheet, contact the Performance Programs department. The interpreted
records from the scans are then sent to the Association for adjustments, EPD calculations and summaries that are provided to the breeders.
As a reminder for weaning time, cow weights with a body condition score need to
be taken +/- 45 days of the calf's weaning measure date. Cow hip heights may be
captured at this time, also. It is important to collect this information after the
cow has weaned her first calf, and then again in subsequent years.
A body condition score must be included with the cow weight in order
for data to be utilized to calculate mature size EPDs in the National Cattle Evaluation.
Any cow weights submitted without a body condition score will not be used.
Cow Body Condition Scores:
- Severely emaciated. All ribs and bone structure easily visible. Very little visible muscle tissue, physically weak.
- Emaciated. Similar to score one, but not weakened. Little visible muscle tissue.
- Very thin. No fat on ribs or brisket. More apparent muscling than on condition score two. Backbone easily visible.
- Thin or with ribs easily visible, but shoulders and hindquarters show fair muscling. Backbone visible.
- Moderate to thin. Last two or three ribs can be seen. Little evidence of fat on brisket, over ribs, or around tail head.
- Good condition. Smooth appearance throughout. Slight fat deposition on brisket and over tail head. Ribs covered, and backs appear slightly rounded.
- Very good condition. Brisket full. Tail head shows pockets of fat. Back appears well rounded due to fat. Ribs very smooth.
- Obese. Back square due to fat. Brisket distended. Heavy fat pockets around tail head. Neck thick.
- Rarely seen. Very obese. Similar to condition score eight, except more extreme. Heavy deposition of udder fat.
For more information on body condition score, click on the link below.
www.cowbcs.info
The American Angus Association generates mature size EPDs that utilize cow weights
and heights on breeding females, as well as their yearling measures (submitted on
the AHIR yearling report form). The Mature Weight EPDs and the Mature Height EPDs
are also used in the $Value index calculations for Maternal Weaned Calf Value ($M), Weaned Calf Value ($W) and Cow
Energy Value ($EN).
For more information about how to body condition score and a scoring table click here
