Merino sheep in South Africa
G J Erasmus
S A Fleece Testing Centre, ADSRI
Private Bag X529
Grootfontein College of Agriculture
The Merino is by far the most important sheep breed in South Africa. According to official estimates there are presently about 30,5 million sheep in the Republic and National States of which 24,2 mil. or 79,4% are woolled sheep. Although no exact figures are available, it can be accepted that the vast majority of the latter are Merinos and Merino derivates.
The Merino is of great importance to South Africa's prosperity, earning more than US $ 200 million annually in foreign exchange from wool exports, granting employment opportunities to thousands of inhabitants and clothing and feeding millions. South Africa is not richly endowed with agricultural resources but, by the utilization of genetic resources such as the Merino, a livestock industry comparable to the best in the world has been established.
There are more than 27 000 wool producers (mostly Merino) in South Africa producing a total of just over 100 mil. kg of wool. Production per producer varies considerably with the 290;0 bigger growers producing more than 80% of the entire wool clip. The average production per sheep is roughly 4,5 kg. The number of annual slaughterings comprises about one-third of the total sheep population giving a meat yield of just over 6 kg per sheep.
The majority of Merino sheep are found in the semi-arid summer rainfall areas which are characterised by times of plenty and times of extreme scarcity. Although relatively small, the winter rainfall area with its established pastures is renowned for Merino sheep production because of the very high yields achieved.
GENETIC IMPROVEMENT OF MERINO SHEEP
The Merino Stud Breeders' Society has a membership of just over 800 and, like all other breed societies, is affiliated to the South African Stud Book and Livestock Improvement Association, a statutory body operating under the Livestock Improvement Act (Act No. 25 of 1977). The Society is unique in the sense that it has two registers viz. a "Merino" register and "performance test" register. The operation and functioning of these registers were fully described at the first World Merino Conference (Eksteen, 1982) but fortunately the Breed Society has been progressive and active enough so that the following new developments can be reported on :
- The performance test register now publishes a catalogue of saleable rams in which the individual's deviation from the mean is adjusted according to the specific stud's deviation from the genetic stable control flock. This is obviously only for studs that have been tested against the control and the traits supplied are 16 months' body mass, clean fleece mass, fibre diameter and wrinkle score. The aim is to give the stud breeder an idea where he can buy rams better than his own and to supply the flock farmer with information as to where he can buy the best rams he can afford.
- The prospect of a sponsored National Championship show for measured performance was mentioned at the first World Conference (Eksteen, 1982). Since then two such championships have been held. Ewes were synchronized to lamb at the same time and, for the first championship, the pregnant ewes were taken to a central point where the ewes lambed and raised their lambs under identical conditions. This proved to be unnecessarily unwieldy an costly and, for the second championship, lambs were raised on the specific farms under a prescribed optimal feeding and management regime and the lambs taken to the central point at weaning. The ram lambs were kept under ad lib feeding in pens while the ewe lambs were run on artificial pastures. Rams and ewes were evaluated at 12 months of age and prizes awarded according to the highest calculated income based on objective measurement and appraisal by judges. The championship was supported by 28 breeders including some in the top hierarchy. Although many problems still have to be overcome, it has become an important event on the Merino calendar.
- The Merino industry has had to gear itself to face the challenges and possibilities of artificial insemination. Young rams showing possibilities, such as show winners, highest priced rams at auctions and those with a large positive deviation from the control, are invited by the Breed Society to participate in a controlled progeny test carried out in two nominated flocks. The rams with the best progeny test results are then submitted for approval to an expert committee as State nominated sires for use in A.I. In this way the dangers of A.I. are avoided, but the advantages exploited.
- A fine example of breeder ingenuity has been the formation of what is known as "veld Merino ram clubs". The reason behind their formation is the high cost of preparing rams for sale, the fact that over-preparation clouds a ram's ability to produce under natural conditions and the fact that different environmental conditions make rams incomparable. The clubs acquire a portion of natural grazing where the members' rams are run together for just on a year after which they are performance tested, approved by the Society's inspectors and sold. A novel approach has been to keep the breeder of each ram anonymous until after the sale.
All the developments mentioned above form part and are extensions of the National Woolled Sheep Performance and Progeny Testing Scheme, one of the five official livestock improvement schemes of the Department of Agriculture and Water Supply. The Scheme provides a comprehensive fleece analysis and data processing service free of charge to its members and has undoubtedly been largely responsible for modernising the age-old art of Merino breeding in South Africa.
The present tendency in Merino breeding in South Africa can be summarised in three words: bigger plainer (less pleated) and finer. The reasons are quite obvious: Lamb and mutton are always in great demand and sell at a premium, being consistently more expensive than any other meat, including beef. In an effort to cash in on this situation, there has been a swing away from Merinos to mutton sheep as reflected by the fact that Merino wool production has decreased by 27,7% from 1970/71 to 1984/85, while the production of crossbred wool has increased by 339,8% over the same period. It therefore seems logical that the Merino should be adapted to utilize its mutton production potential. Breeders are however constantly warned not to place the emphasis on correlated traits only, but to select directly for traits such as reproduction rate, mothering ability and growth rate, while wool production should under no circumstances be forfeited. The National Woolled Sheep Performance and Progeny Testing Scheme has devised a programme for the recording of ewe productivity where the selection criterion is presently: (3 x fleece weight of ewe) + (total weight of lamb weaned). The inclusion of some measure of ewe productivity as well as growth and fleece traits in a mixed model (BLUP) prediction of breeding values is envisaged for the future.
The reason for the emphasis on fineness is also obvious and is probably presently encountered in all apparel wool-producing countries. In the past the price premium for finer wool has not provided enough incentive to breed a finer wool. In fact the recommendation by scientists was that selection should be aimed at keeping fibre diameter constant and increasing clean fleece weight and selection indexes were constructed to do just that. Most breeders however did not even attempt to keep fibre diameter from changing and sometimes selection was even aimed at increasing fibre diameter. This, together with possible improvements in feeding and management practices, has led to a decrease in the fineness of the South African wool clip.
Nevertheless, South Africa is still a fine wool producing country in relation to other large wool producing countries as can be seen in FIG 1.
These problems around fineness have served to highlight the need for selection by objective measurement and for total monetary return. The South African Merino breeder is indeed fortunate to have all the necessary facilities readily at his disposal at little or no cost.
Mass selection is generally recommended for Merino sheep because the heritability of the important traits, with the exception of reproduction rate, is normally moderate to high and these traits are not sex-linked. Artificial insemination is, however, no longer a farsighted dream in the sheep industry and this brings the need for progeny testing, as already mentioned. Also, the advantages of implementing Henderson's "Best Linear Unbiased Prediction" (BLUP) of breeding values on a within- and across-flock basis must be realized and this requires the keeping of pedigree records. The Merino stud industry will seriously have to consider the recording of pedigrees with performance on a far larger scale. Unfortunately the breed structure of the Merino is such that not all studs are genetically tied, making a whole-breed analysis impossible. A plan could however be devised where rams from the control flock could be used to supply the necessary ties.
The Merino sheep is a prime example of what can be achieved by selective breeding in livestock. South African Merino breeders are justly proud of what they have achieved but this pride is secondary to their excitement over what still can be done.
OTHER WOOLLED BREEDS
The two most important other woolled breeds in South Africa are the S A Mutton Merino and the Dohne Merino. The former was imported from Germany (German Merino) but, because breeders claim that it no longer resembles the original stock, the name has been changed to South African Mutton Merino. The Dohne Merino emanated from a cross between the original German Merino and the pure Merino and was developed for the sour grassveld areas. It is gaining in popularity for reasons already mentioned and has spread to most sheep producing areas. Both these breeds are very efficient in the utilization of low quality roughages.
An important lesson learnt from the severe drought that has ravaged almost the entire African continent over the past few years is that livestock production in the marginal cropping areas could lead to far greater stability. Although the emphasis will necessarily be on meat production to feed a growing population, Merinos could grant even greater stability as wool production is not subject to seasonal over-supply. The logical way to utilize the Merino is as the maternal breed in crossbreeding programmes. The only proviso is that the fertility of the Merino should be improved and projects are already underway in an attempt to achieve this.
In spite of the fact that the price of farms in the sheep grazing areas has increased by 278% in the past decade, natural grazing is still the cheapest source of sheep feed. There is therefore growing concern over the deterioration of natural veld owing to grazing malpractices such as overstocking. Apart from the relatively small possible horizontal expansion mentioned, sheep numbers will in all probability have to diminish rather than increase in South Africa. The only possibility for increased total production then is increasing production per animal.
This is the challenge facing the Merino industry in South Africa. The breed and its caretakers are ready to meet it !
All the statistics given were supplied by the S A Wool Board and the Division of Agricultural Marketing Research.
EKSTEEN, T.J.C. 1982. Merinos in South Africa. Paper presented at First World Merino Conference. Melbourne 1982.
HARDISTY, D. 1985 Presentation to the 56th annual congress of the National Woolgrowers' Association of South Africa. 24 July 1985.
Karoo Agric 3 (7), 4-6