Dr. John Hough, Chief Science Officer, EPD International, Inc.

Cattle can be directly compared genetically only if they have been raised
together and have been given the same opportunity to perform. In other words,
an animal must have contemporaries in order to make the performance data
meaningful. When submitting performance data to the Senepol Cattle Breeders
Association, it is critical to identify and manage contemporary groups correctly.
If problems arise because of incorrect grouping, it is possible that all of your
performance data may not be used by the University of Georgia in the National
Cattle Evaluation (NCE) to calculate EPDs. Unfortunately, some breeders do
not completely understand the results of incorrect groupings for performance
information. There are a few simple rules to follow to insure performance
records are useful and can be utilized in the genetic evaluation procedures.

Birth Contemporary Groups

Calves born within the same birth contemporary group can be directly compared
to each other. Birth contemporary groups are determined by calf crop number,
sex, birth type, year and season. Initially, a birth contemporary group is
performance information from a group of calves sent at one time to SCBA by a
breeder. These calves need not all be owned by the same breeder. For
example, junior member's calves can be in the same contemporary group as
their parent's cattle. A birth contemporary group contains calves born within 90
days of one another. Calves of the same sex are grouped together. Note that
sex is male versus female rather than bull, steer or heifer since steer calves are
always born as bulls. Calves of the same birth type are compared to each other.
For example, single birth calves are not compared to multiple birth such as
twins and triplets nor are they compared to embryo calves. Only single birth
calves are used in the NCE. Performance measurements from embryo transfer
and multiple birth calves are not utilized.

Weaning Contemporary Groups

Weaning contemporary groups are defined by the calf crop number, weaning
sex, birth type, weaning management code, weaning management group,
weaning age group and weaning weigh date. First, a weaning contemporary
group is performance data from a group of calves sent at one time to SCBA by
a breeder. Calves of different sexes are in different weaning contemporary
groups. Note that birth sex and weaning sex need not be the same, because
male at birth could be either bull or steer at weaning. Breeders should be careful
to designate sex correctly, because calves castrated at weaning are actually
bulls rather than steers for weaning evaluation purposes. Calves of different
birth types are placed in different weaning groups. In addition, multiple birth and
embryo transfer calves' weaning information is not utilized in the NCE. Weaning
management code and group also distinguish weaning contemporary groups.
These two codes allow the breeder to tell SCBA that calves have been
managed differently. Weaning management codes of '1' and '2' are used in the
NCE analysis. Weaning age groups are categorized as early (less than 160
days of age), standard (160-250 days of age) and late (over 250 days of age).
Performance data from calves within only the standard age group are utilized for
the NCE analysis. Finally, calves weighed on different days are placed in
different contemporary groups for the NCE analysis. This is done since most
calves weighed on different days have probably been raised in different
environments or have had different types of management.

Yearling Contemporary Groups

Yearling contemporary groups are defined by the weaning contemporary group,
yearling sex, yearling management code, yearling management group, yearling
age group, yearling stage code and yearling weight date. Initially, a yearling
contemporary group is performance figures from a group of cattle sent at one
time to SCBA by a breeder. Yearling sex can again be redefined since calves
can be castrated at or after weaning. Breeders can describe specific
management differences with yearling management code and yearling
management group. Cattle with different codes and groups are placed in
different contemporary groups. Yearling age groups are categorized as early
(less than 330 days of age), standard (330-450 days of age) and late (over 450
days of age). Performance data from cattle within only the standard age group
are utilized for the NCE analysis. Finally, calves weighed on different days are
placed in different contemporary groups for the NCE analysis. Again, this
guideline is used because most cattle weighed on different days have probably
been raised in different environments or types of management. Adjusted 452-
day (stage 4, 15 months of age) and 550-day (stage 5, 18 months of age) can
be calculated. Only stage 3 (12 months of age) weights are used for the NCE
analysis. In addition, for the NCE analysis, yearling performance can not be
utilized if weaning performance was not used.

Incorrect contemporary designations are probably the greatest cause of
inaccuracy in the National Cattle Evaluation when calculating EPDs. One of the
most important items is the correct grouping animals. Breeders are completely
responsible for indicating the proper management codes and groups. The
second column of the code should be used to denote different environmental or
management conditions. For example, calves nursing cows in different pastures
should be grouped separately for fair comparisons. Show cattle receiving
special treatment should also receive a different management code.
Management codes are explained on the reverse side of your Guide Lines
forms.

Performance information is most useful if breeders concentrate on a few details.
Calves should be managed in groups as large as practical. Calves should be
managed alike and all weighed on the same date. Contemporary groups should
include calves sired by at least two bulls. This is not mandatory but will increase
the overall accuracy of genetic evaluation and will spread your genetic risk
across more than one bull. Accurate and factual record keeping is essential.
Also, actual weights and measurement must be collected. Estimates of an
animal's weight are not acceptable means to record birth, weaning or yearling
weights. Visual appraisal does not compare to a set of balanced scales. It is
extremely important that all calves be recorded, not just the better ones.
Records for the registered calves as well as those not registered should be sent
to SCBA. All calves, registered or unregistered, must be from registered
parents. Especially important are birth weights and calving ease scores for dead
calves. These are the calves that need most to be identified. Recording dead
calves also assures that cows are given credit for calving even though the calf
may have died. Fair comparisons are difficult to make using pre-selected
records. If you only send in the better portion of your calves, they will not fare
nearly as well compared to recording the entire calf crop.

If you follow these few guidelines in recording performance information, the
accuracy of genetic evaluation will be dramatically increased for your own use
as well as for the entire breed If you have any questions or comments please
contact SCBA.