  BeefTalk:
Evaluate Sire Selection Birth Weights Using Data
By Kris Ringwall, Extension Beef Specialist,
NDSU Extension Service
Calving is in full swing, or shifting to high gear. So now is the time to find
out the answer to the question: How did last year’s bull selection influence
calf birth weight? A careful evaluation of the facts is always the best
approach, especially after having assisted with the difficult birth of a calf.
Over the years of working with producers, birth weight has always been a
lively topic on which most cattle producers freely comment. But many of those
comments are not based on actual data. Don’t speculate. If you want to know
what a calf weighs, weigh it.
Estimated weights or fancy tapes are not true birth weights. Birth weights
are not easy to get, but a sample is better than nothing. Since birth weight is
not required on all calves, even a sample of calves will give a producer an
estimate of the current birth weight. For producers who don’t weigh every
calf, I recommend selecting one day a week or some preselected dates and only
weigh the calves born on those days. If there is a college student home on break
or the basketball season has come to an end, take advantage of that extra help
and get a true recording of the birth weight of your calves.
Currently, several sires are producing calves in the North Dakota State
University Dickinson Research Extension Center herd. Despite the cold weather,
calving has gone reasonably well. My goal is to reduce calf death loss. However,
based on the start of the season, I don’t believe that will happen.
To date, seven of the 76 heifers calved lost their calves. Two heifers needed
assistance with mal-positioned calves, one had a set of twins (both died), and
the other four calves were all small. In fact, the average birth weight for the
eight calves from the seven heifers was only 61 pounds.
The two Angus artificial insemination sires used on the heifers were 1458 and
1550. The average birth weight on 37 calves sired by 1458 (birth weight EPD:
-0.3) is 74 pounds and on 36 calves sired by 1550 (birth weight EPD: +0.9) is
72.8 pounds. In all reality, some of the calves are simply too small.
Although subsequent growth may be good, small calves do not withstand the
rigors of winter very well. First-calf heifers may not be aggressive enough to
stimulate the calf and small calves will experience hypothermia quicker than
heavier calves.
The mature cows are doing slightly better. We have lost six calves from 130
cows. This is the first year the Center has opted to calve 192 cows in the new
DREC out-wintering facility, away from the protection of the ranch headquarters.
What a nice winter it was until the cows started to calve. The cows at the
out-wintering facility are only checked in the evening and again the following
morning. No night checks are done, since the cows are three miles away. To say I
was nervous would be an understatement. Despite wind chills greater than -25 F,
only four calves have been lost to date.
Of the cows close to headquarters, only two calves died--one was deformed,
the other eaten by coyotes. The latter calf’s mother died from a heart
rupture. Although it’s speculation, I can not help but wonder if the cow died
in defense of her calf or her death resulted in a defenseless calf. The Angus
artificial insemination sires used on the mature cows were 127, 207, and 196.
Their average birth weight was 91.3, 88.6 and 76.5, respectively. Birth weight
EPDs for these three bulls were +2 for 127, +1 for 207 and +0.4 for 196.
In conclusion, the bulls worked and hopefully as the weather warms, calf
death loss will abate. In the meantime, now is the time to make adjustments in
next year’s bull line up and finalize the turn out date. As for the
out-wintering facility, I plan to delay bull turn out by two weeks.
May you find all your ear tags.
Your comments are always welcome at www.BeefTalk.com.
For more information, contact the North Dakota Beef Cattle Improvement
Association, 1133 State Avenue, Dickinson, ND 58601 or go to www.CHAPS2000.COM
on the Internet. In correspondence about this column, refer to BT0083.
###
Source: Kris Ringwall, (701) 483-2427, kringwal@ndsuext.nodak.edu
Editor: Tom Jirik, (701) 231-9629, tjirik@ndsuext.nodak.edu
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March 18 Calving Update
DEATH LOSS
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Cows at Cows at
Out-Wintering Ranch
Calves Heifers Facility Headquarters
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Number Dead 8 4 2
Number Born 76 68 62
Death Loss Percentage 10.5 5.9 3.2
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AVERAGE BIRTH WEIGHT FOR SELECTED AI SIRES
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Birth Weight
Birth Actual Adjusted to
Sire Cow Age Weight EPD Birth Weight Mature Cow
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127 Mature 2.0 91.3 94.5
207 Mature 1.0 88.6 91.1
1550 Heifers 0.9 72.8 80.8
196 Mature 0.4 76.5 79.8
1458 Heifers -0.3 74.0 82.0
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NDSU Dickinson Research Extension Center
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