- Why Performance Testing?
|Last update: March 30, 2012 09:49:07 AM|
Why Performance Testing?
Gert Erasmus, S.A. Fleece Testing Centre
PERFORMANCE testing today forms the basis of breed improvement of nearly all kinds of livestock in all the developed Western countries of the world. In South Africa, too, performance testing is being accepted readily as an indispensable aid in animal improvement. In fact, as far as methods and techniques are concerned, South Africa can be regarded as a world leader in many aspects.
The obvious reason for the success obtained by using performance testing is that it leads to more accurate selection of superior breeding stock. This, however, is only part of the whole story and it must be stressed that performance testing merely supplies data and that breeders differ in their ability to utilize these data in the same way that they differ in their ability to select animals efficiently without objective measurements. Given the best measuring technique and data processing system, the incapable breeder could still make a terrible hash of his breeding enterprise.
Apart from the primary and initial objective of more accurate selection, experience has shown that performance testing also leads to the following:
A Rationalisation of Breeding Aims
One of the most important consequences of performance testing is that it leads to the scrutinisation of the relative importance of the different traits for which we select. This not only applies to measurable but also to immeasurable attributes. In pigs for instance, performance testing has highlighted the importance of good legs and the enormous problem the pig industry has in this respect. The same applies to excessive folds in Merino sheep in harsh environments. Animal breeding is extremely complex in the sense that different characteristics, some positively correlated, some negatively correlated and others un-correlated, some very important, others less important, make up the total economic and breeding worth of an animal. Without figures it is virtually impossible to select sensibly for such a very complex combination. Also bear in mind that the economic value and the breeding value of an animal is not necessarily the same thing, as some traits are readily passed on to the offspring while others have a low heritability.
Performance testing invariably has, as a first consequence, the formulation of breeding objectives which are sensible, realistic and based on fact.
Without performance testing the stud breeder could easily fail to appreciate the exact needs of his final customer, the commercial producer. An example of how easily this can happen is the fact that many beef cattle breeders insisted on selecting for traits such as coat colour, shape of horns, etc., while the commercial producer's needs shifted to economically important properties such as fertility and growth rate.
Farmers are notoriously allergic to the keeping of records, that is until they start doing performance testing. A set of breeding records that consists of unbiased figures that can be used to calculate averages and deviations, is the heart of a modern breeding venture. It allows the breeder to accurately monitor the effect of his actions enabling him to take timely action where necessary. A breeder's own set of effective records also safeguards him from the evil of so many dangerous generalisations which are so easily made in breeding. On the other hand written records without figures, which mean the same to everybody and go on from year to year, are worse than useless as they could be misleading.
One of the most important functions of the performance testing schemes in South Africa is to translate raw data and measurements made on animals into information which the breeder can use. Not only is the effort required in the keeping of records in most cases radically reduced, but at the same time the value of these records is greatly enhanced.
A Keener Interest
Performance testing is basically an aid in breeding. It is, however, wonderful to see what an effect it normally has on other aspects of management. The countless success stories recently related at a symposium at Bloemfontein and at other gatherings, emphasises the fact that in practice it has a far greater effect on increasing production efficiency. As one breeder so aptly put it: "The best method of promoting a breed is to promote performance testing within the breed."
More Applicable Research and More Efficiency Extension
In any livestock industry performance testing, as we know it, forms the vital link between extension and research. It is an accepted fact that one of the major shortcomings in the South African livestock industry is the sketchy or, in some cases, complete lack of vital statistics. It is, therefore, not always possible to concentrate our limited research resources on the real problems because they are difficult to pinpoint. On the other hand, it is very difficult today to do proper extension and give correct and valuable advice without the necessary figures to prove the point. Not many years ago a potential car buyer would merely have looked at the different products available and then have made his choice on looks and personal tastes. Today he reads through test reports and studies figures on fuel consumption, speed, acceleration, fuel tank size and even wind resistance, before making a decision. It is becoming extremely difficult to convince people without facts and figures.
New Possibilities are created
During the early stages of breed improvement, progress is normally quite rapid. Any method of selection, including "hand-and-eye", is then usually effective as differences between animals can be readily detected. Later, however, differences become difficult to assess and, even more important, progress invariably becomes extremely difficult due to unfavourable genetic correlations between traits. It appears as if Angora breeders are not immune to this problem. Fineness, which is of the utmost economic importance, seems to be associated with lower bodyweight which is again associated with lower fertility. The only solution to this problem is the measurement of these traits, so that they can be quantified and combined in such a way that selection for one trait will not lead to a deterioration in another.
In a stud breeding industry there are usually nearly as many different beliefs as there are breeders. Without the necessary figures, there is no way that these beliefs can be substantiated or disproved. When figures become available, senseless arguments make way for constructive discussions which have already proved to be extremely effective, not only in increasing efficiency, but also in bringing about valuable changes and refinements in methods and techniques. In the case of the Performance Testing Scheme for Woolled Sheep, it is interesting to note that the emphasis in selection is rapidly shifting to a completely different set of parameters to those that were regarded as the only essential ones at the start. New and extremely exciting horizons have been opened, such as the possibility of accurately identifying the top sires in the industry and disseminating their superiority by the use of AI. It also appears that there are vast differences, hitherto undetected, in total ewe productivity which, if properly exploited, could give the industry a tremendous boost.
Performance testing is the first step in applying the principles of modern breeding science to the improvement of a breed. Starting with performance testing is today the most important decision a breeder can wish to make and will probably be the most exciting step that he will ever take.
Angora goat and mohair journal 25 (1)