  BeefTalk:
Records Can Provide Opportunities for Maximum Heterosis
By Kris Ringwall, Extension Beef Specialist,
NDSU Extension Service
Uniformity within the cow herd is a goal of most beef producers. Once
achieved, uniformity needs to be retained.
One of the privileges of working in a university environment is the
opportunity to teach and interact with those exploring a career in agriculture.
Recently, I asked a question regarding production records. If I might paraphrase
one response: "Why would anyone keep records on a commercial cow?"
This is a common question, so after taking a deep breath and brief pause, I
noted we would be starting from the basics. Seldom, in any group of students,
will the concepts of performance recordkeeping in a commercial operation be
well-ingrained. Generally, the students accept the concept within the bull
buying segment of the industry by assuming the purebred producer is keeping some
level of records.
So, starting from the basics, I present a principle accepted even in the
commercial business: cows should not be mated back to their own sire. This is
the principle of inbreeding, and inbred lines of cattle have, for all practical
purposes, proven nonfunctional for many reasons. In general, reproduction, calf
viability and general thriftiness suffer. Some type of identification system is
needed to avoid these three problems, even within a commercial herd.
Inbreeding is not only a function of a sire daughter mating but also
relationships on both sides of a pedigree. Anytime a bull or cow is on both
sides of a pedigree, these relationships generate a percentage of inbreeding in
the offspring. A common, and wrong, assumption is that the larger breeds do not
have to worry about inbreeding relationships.
The North Dakota State University Dickinson Research Extension Center has
used a pool of 21 Angus sires in an artificial insemination program. A critical
look reveals the pool is not as large genetically as you might think.
A simple way to check is to do a quick review of the bull pedigrees which can
be printed very easily from www.angus.org.
These pedigrees go back three generation and seven male ancestors are listed for
each bull. One way to look at how related individuals are, without going back to
calculate the actual inbreeding coefficient, would be to simply count how many
times a particular bull shows up on the various pedigrees.
If none of the bulls are related, reviewing 21 pedigrees should produce 21
times 7 different bulls listed as ancestors, or 147 bulls. The quick pedigree
review indicates several names repeated. Tehama Bando 155 shows up on nine of
the pedigrees 10 times. The bull QAS Traveler 23 4 also shows up on 10
pedigrees. Other bulls that show up more than once are PS Power Play and N Bar
Emulation Ext.
Purebred breeders search pedigrees often but back to the original question,
"Why should commercial breeders keep records?" I could expound on several
reasons, however in this case I will only pick on one, the negative effects of
inbreeding do not belong in a commercial herd.
For the Dickinson Research Extension Center, what appears as a very large
genetic pool from 21 Angus bulls does not actually exist. All these bulls have
or will have daughters in the herd. In order to avoid inbreeding, related
individuals should not be mated to each other. Of the 21 bulls, 10 bulls are
related to Tehma Bando within three generations and nine are related to QAS
Traveler 23 4 within three generations. Just out of curiosity, I checked these
two bulls’ pedigrees on the web site, and guess what, both bulls are sons of
Band 234 of Ideal 3163. So in retrospect, 15 of the 21 bulls have Band 234 of
Ideal 3163 as a common ancestor.
As a result, I better know which females I should mate to which bulls.
Commercial cattle need the benefit of heterosis, not the negative effects of
inbreeding depression.
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 BT0134.
###
Source: Kris Ringwall, (701) 483-2427, kringwal@ndsuext.nodak.edu
Editor: Tom Jirik, (701) 231-9629, tjirik@ndsuext.nodak.edu
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Graphic --
Common Ancestors Within Three
Generations of 21 Angus Bulls
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Percentage of
Bull Name Similar Pedigrees
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Tehama Bando 155 43
QAS Traveler 23-4 48
PS Power Play 24
N Bar Emulation Ext 24
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Within Four Generations
Band 234 of Ideal 3163 71
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