Last update: April 3, 2012 10:50:02 AM E-mail Print



G. Erasmus


In the past Merino breeders have tried to select an animal which to them represented the model of optimal production. Their efforts towards what they envisaged as the appearance of the sheep they desired were always clear in the back of their minds. Thus many breeders made a grand success of breeding precisely such sheep or, at least, reasonably accurately. But now we have the spectacle of a new generation of "whitecoats", the so-called sheep geneticists. What they ask is: "Do you know precisely what a sheep should look like to feel happy and produce optimally?"

In addition they want to know if there are not many who fail to appreciate the strong influence of feeding and management of a sheep's appearance as a genetic effect which can be transmitted to the progeny.

"No," they say, "rather select according to measured production and don't try to breed ideal and balanced sheep, but try to raise the average production of the flock by increasing the number of good genes in the flock and decreasing the weak genes. To do this you must ensure that those sheep which carry the best genes far the production characteristics are selected by making accurate comparisons between sheep which have been subject to the same conditions." Many breeders understand this approach by now and appreciate its keen logic. They are no longer led astray by the excellent impression made by pampered sheep and neither are they blind any longer to the patent results which have been achieved in the case of a variety of animals, even the Merino, by this scientific approach. However, what worries, or merely interests, us all is what the Merino of tomorrow will look like when all breeders use performance testing for selection.

It is beyond doubt that performance testing will yet become standard practice in improving the breeding of woolled sheep. But while this is not yet so we are not given to know exactly what a sheep should look like in order to furnish as efficiently and economically as possible what we expect of it. True, we have certain indications, but have learnt by now that it can be dangerous to become too addicted to all kinds of demands on the poor sheep of whose inner nature we know very little in reality.

These few thoughts on the appearance of the Merino of the future must thus be regarded as pure speculation or, at its best, a personal, calculated guess.

Firstly, it will depend on how production is defined; in other words what we are going to demand of the Merino. For effective selection through performance testing a clear definition of aims is a primary requisite. One of the points newly stressed by performance testing is that we know very little as yet of the actual market requirements of our sheep products. Market research and breeding improvement are inseparable and the needs and preferences of the manufacturer and the consumer will determine to a large extent what tomorrow's Merino will look like. The success achieved by each breeder and, indeed, whether our industry will continue to exist and thrive will depend on the accuracy with which future market needs are gauged. A personal shot at doling it as well as possible is therefore incorporated in the following sketch of the future Merino sheep.

The most conspicuous characteristic of this sheep is that it is bigger and plainer bodied. This is the result of the selection for body mass and fertility. There is no noticeable difference between the appearance of stud and flock sheep. The difference is determined by measured performances under controlled conditions. Because selection is practised in natural conditions the sheep is well adapted to its environment and is easy to farm. Its conformation is somewhat wedge-shaped – broad behind and slightly narrower in front with a slightly drooping rump. Thus difficult labour is rare and because the sheep are more plain-bowed the lambs are small at birth but the selection for higher body mass at the two-tooth stage will have resulted in a high weaning mass. The sheep have nice open faces, strong but rather bare legs and the hocks are passable but not marvellous according to the old standards of the breed. The future sheep has a long body and actually looks bigger than it is because it is somewhat higher on its legs.

Despite having fewer pleats the sheep produces a larger amount of clean wool. This is primarily due to the large skin surface of the bigger animal, a better staple length and a larger number of fibres per unit of skin surface. The wool is slightly drier but there is little weathering because of better density and good staple formation. Because the wool is always under-crimped and contains enough fluid yolk it handles softly but its quality and richness are by no means exaggerated. In short it amounts to this that stud sheep also carry good commercial wool and not a special kind of "stud wool". Once again classifications are made as a result of measured performances according to statistically planned comparison tests.

Although the wool looks stronger judging by crimp the fibre diameter in most studs is between 20 and 25 microns. Rams with good performances throughout and a low fibre thickness are scarce and it is they in particular who are sold at a premium.

This, to be brief, is purely personal conjecture as to the futures Merino's looks. If it is anywhere near the mark time alone can tell. The aim was not to prescribe to the markets what their needs should be nor to lay down to sheep and nature how they could best meet them, but, on the contrary, that every breeder shall test his own prescriptions with objectivity against actual measurements and market data. The author knows it is easier to draw the wool over one's own eyes than anyone else's.



Merino Breeders Journal 38 (2)