Jacque Francois Els writes about the importance of following the correct procedures in animal recording.
The late Prof Jan Bonsma coined the phrase; “ To measure is to know”. If something is not measured, how can statements be made and conclusions drawn? Does that mean that data can be randomly collected and will have any real meaning? Unfortunately not, for as the saying in the computer industry goes; “Garbage in – garbage out!” or “You only get out of something what you put into it.” This is particularly true regarding performance recording, especially for genetic evaluation, in terms of both the volume and the quality of the data recorded.
Pedigree recording
Without any doubt, it cannot be reasoned that any data recorded concerning an animal, will be of value, if the parentage (pedigree) of the animal is not correct. Incorrect parentage will have a marked influence on an individual animals EBV’s, and that of its relatives. With the availability of DNA tests, it became possible to test for correctness of parentage. Mostly tests were only done for sire verification and sometimes resulted in the exclusion of the nominated sire, or the results indicated that more than one sire could be the sire. In such cases the dam was needed to provide more information to be able to identify the correct sire. Thus it is always better to test both the dam and sire as the parents of an individual, it eliminates the possibility for mistakes. With the availability of genomic marker tests, this becomes easier, for when both parents have been genotyped, the test for an animal will provide proof of parentage. Since the introduction of genomics, many recorded parentages, have been proven wrong, and has caused upsets in breed societies.
The question is often asked; “What size herd do you need to obtain effective results.” Whilst there is no minimum herd size requirement for herds wishing to participate in performance recording, there are a number of considerations that small herds need to make to ensure that the performance information that they record for their animals can be analysed effectively.
There are two main concepts that all herds, irrespective of size, need to understand, if they want to obtain effective results from their BREEDPLAN analysis. These concepts are contemporary groups and the creation of genetic linkages. Small herds in particular should look at implementing management strategies that maximise the size of the contemporary groups; rather use 2 breeding bulls and have two contemporary groups of effective size than three or four with ineffective contemporary group sizes, and ensure genetic linkage both within the herd; always have a bull(s) that roll over years and with other herds in the breed; use bulls from other herds as well, not only your own.
Thus; “Whatever you do, do it right!” Rather collect data on a small number of traits, ensuring that it is correctly recorded/measured, than data collection on a large number of traits, but the minimum requirements for meaningful analysis are not complied with, eg. If as a breeder, due to management problems, are not able to weigh animals at the prescribed times, then rather ensure that you weigh all the calves and their dams at weaning ,creating effective contemporary management groups, than weighing only a small portion of animals of different ages that are available at the time of weighing, thus creating ineffective contemporary management groups. It might provide to the uninitiated a picture of you are doing performance recording, but it is meaningless. There will be biases in the data for not all data has been collected.
Contemporary Groups
Understanding Contemporary Group Formation
A contemporary group can be described as animals from the same herd, of a similar age and run under the same conditions i.e. animals that have had the same opportunity to perform.
- For most performance traits, calves will be analysed in the same contemporary group if they:
- Were bred in the same herd
- Are of the same sex
- Are of the same birth number (i.e. twins are not compared to single calves)
- Are of the same birth status (i.e ET calves are not compared with AI/Natural calves)
- Were born in the same calving year
- Were born within 45 days (for birth and 200day weight traits) and 60 days (for 400 and 600 day weight, scrotal and scanning traits) of each other
- Have been weighed on the same day (& have the same weighing history)
- Have been run under the same conditions (breeder allocated management groups)
Creating Effective Contemporary Management Groups
There are a number of ways breeders can use to manage their herds to create effective contemporary management groups.
- Restricted calving periods – as calves are generally only included in the same contemporary group if they are born within 45 or 60 days of one another, it is recommended that herds aim to have a restricted calving period.
- Run all calves under the same management conditions (Combine breeding herds into larger herds after the mating season, and run together till weaning). Where calves have to be split into different groups, eg. Male calves into bulls and steers, weigh the whole group before it is split.
- Record performance for all animals on the same day – as BREEDPLAN only directly compares the performance of animals that has been recorded on the same day, it is important to record performance for all animals within a contemporary group on the same day (e.g. weighing off all heifers on the same day).
- Inclusion of commercial/unregistered animals – many breeders have a small stud herd and a larger commercial herd, run in conjunction. If the commercial animals are of similar breed content than the stud herd, it may be possible to record these animals with the relevant Breed Society. This will allow for greater number of animals to be included in the same contemporary group.
- Associated herds – Where two breeders run their animals together on the same property, BREEDPLAN can associate the two memberships to allow the performance of claves in both herds to be directly compared together.
- Use more than one sire – The BREEDPLAN analysis will be more effective if at least two sires are represented in each contemporary group as the performance of the progeny will contribute to the calculation of the EBV’s of their sire. Where AI programmes are used they should be timed so that AI sired calves are born at the same time as the calves sired by natural mating.
- Supply recipient dam details – Herds that use ET need to identify the breed and age of the recipient dams of ET calves. If the breed is not supplied,ET Calves are split into single animal contemporary groups and therefore their performance is not effective. To maximise the analysis of ET Calves by BREEDPLAN, it is preferable if the recipient dams are all of the same breed.
Whole Herd Recording
Wherever possible, whether it is a small or a big herd, studbreeders should adopt a strategy of whole herd recording. This involves recording all calves with the relevant breed society (dead or alive) and recording performance for all the animals in contemporary groups with BREEDPLAN. Because BREEDPLAN uses not just individual performance in the calculation of EBV’s, but also the performance of all known relatives, it is recommended that performance be recorded on all available animals, eg. steers, heifers and bulls, as opposed to just performance recording bulls.
Source: Brahman Journals