Fall Data Gathering
As calves are being weaned and weighed this fall, data will be entered into the CSA system and incorporated into each animal's IGS evaluation. It is extremely important to report weights on all the calves that are weaned (including the duds) and to identify any management group differences between animals.
The reasons for complete reporting are many, but 2 keys are evaluation of maternal ability and the elimination of reporting bias. Sustained cow life could be described as "successfully weaned a calf for X years". Failing to report a weaning record on a calf, unfairly biases the dam's performance record downward. Secondly, only reporting the top calves in a group means that they are artificially downgraded when calculating their performance relative to the group. A simple example is shown below.
|
Calf
|
Birthdate
|
Sex
|
WWT
|
Mgt Grpt
|
Sire
|
Dev
|
Dev 2
|
|
A
|
Jan 1
|
M
|
850
|
1
|
Z
|
+100
|
+50
|
|
B
|
Jan 15
|
M
|
750
|
1
|
Y
|
0
|
-50
|
|
C
|
Jan 15
|
M
|
650
|
1
|
Z
|
-100
|
|
If the breeder reports all the calves, the heaviest calf (A) is 100 pounds heavier than the group average (Dev). If the breeder decides Calf C is not worth registering so does not report his weight, Calf A now has a deviation (Dev 2) of only 50 pounds above group average, and Calf B that was average is now at -50. This can adversely affect the evaluation of all the cattle.
Management group numbers are used to identify calves that are managed in the same way between calving and weaning. Simply identify those calves that had the same opportunity with the same management group number. Management groups are further divided into Contemporary Groups which are key to genetic evaluation. Fair evaluation is difficult if calves that are given a preferential environment are compared directly with calves that have not had the same opportunity.
Complete Data and DNA
High density DNA tests are increasingly popular with CSA members. The tests have the ability to provide parentage information and feedback on specific traits (example: Homo Black), but also to contribute to increased accuracy of genetic evaluation for a variety of traits. It is more important than ever given this technology to ensure that we do a good job of collecting complete phenotypes (performance data) on full contemporary groups of cattle. Currently as you are weaning, preg-testing and completing the THE enrolment forms that are either online or headed out in the mail fairly shortly, please be sure to complete information on all calves where possible and complete breeding information, even on those that may have been preg-tested open.
This not only helps the current evaluation but allows us to continue to improve the power of DNA technology. In the genetic evaluation, DNA works by associating specific pieces (SNPs) of DNA with a trait response. For example, if an animal has SNP ABC at position 1 then it will have more growth than if it has version ABB. Over time, as breeders select a trait (in any direction) the prevalence of specific SNPs will increase and they will thus become less informative. By continuing to collect complete phenotypic data, we can continue to re-examine how much information various SNPs provide and continue to maintain and advance the power of the SNP panel results.
Remember, when you are completing your THE, weaning and other performance information this fall, you are also doing your part to improve the power of DNA.
