The origin of the Dormer from a cross between Dorset Horn rams with German Merino ewes (presently known as the S A Mutton Merino) was a direct consequence of a series of extensive slaughter lamb experiments carried out at the Elsenburg Research Station of the Department of Agriculture since 1927 over a period of more than ten years.
The name DORMER is an abbreviation of the linkage Dorset-Merino. The main object with the development of the Dormer was to breed a mutton breed which could adapt to conditions in the winter rainfall area of South Africa (cold and wet) and from which suitable rams could be produced for cross breeding purposes. The aim was a slaughter lamb breed which could produce meat rapidly and economically. A contributing factor in the development of the Dormer was to breed a sheep of which, at the Smithfield market in England, the lambs could compete with slaughter lambs from Australia and New Zealand, the reason for this being that the local market was very depressed and precarious during the depression years.
Rams of a large variety have been used in the Elsenburg experiments. Amongst these were the Dorset Horn, Border Leicester, Ryeland, Romney Marsh, South Down, Suffolk Down, Texel, Corriedale, German Merino and the Blackhead Persian. Merino ewes were initially used as dams.
In an effort to breed a bigger ewe with a better mutton conformation (than the Merino) without changing the Merino's wool characteristics, the German Merino ram was used on Merino ewes. Lambs from these crossbred ewes, mated with Dorset Horn rams, showed a greater average daily gain than any of the other cross bred lambs. This finding was contributory to the fact that pure South African
Mutton Merino ewes were subsequently used in the cross breeding programme.
In 1936, following experiments performed out over eight years, the conclusion was reached that the Dorset Horn ram had given the most outstanding performance as regards mass gain and carcass quality of lambs begotten from crosses with Merino ewes. A finding in favour of the Dorset Horn and the SA Mutton Merino was that, of the imported breeds, they were the only two to produce a satisfactory lambing percentage in autumn. This trait is of the utmost importance in the Western Cape where primarily winter pastures are utilised for the production of lambs.
An abnormally high mortality rate occurred under mature Dorset Horn sheep as a consequence of low resistance to infection with the lung parasite muellerius cappilaris. In contrast, the SA Mutton Merino, producing under the same conditions experienced no abnormal deaths. The deduction was made that either the SA Mutton Merino was not as vulnerable to infection or that it was highly resistant to infection with the lung parasite. On the strength of favourable results achieved with the Elsenburg slaughter lamb experiments and the marketing of carcasses on the Smithfield market, it was decided to conduct similar experiments on a cooperative basis over the entire winter rainfall area. The purpose was to investigate the possibility of developing a profitable slaughter lamb industry which would, to a large extent, be aimed at the overseas market. To give effect to this, the Council of Control over the Livestock and Meat Industries (currently the South African Meat Board) proceeded during the years 1936 and 1937 to import several hundreds of the British mutton breed rams from Australia and England. A number of the rams were put out on loan for the cooperative slaughter lamb experiments. The rams were mainly crossed with Merino ewes. During the years 1937 and 1938 more than 6000 lamb carcasses were shipped to the Smithfield market as experimental consignments. From these large scale cooperative experiments it was confirmed that the Dorset Horn rams were the best producers of slaughter lambs.
The idea of creating a new mutton breed from a cross between Dorset Horn rams and German Merino ewes (SA Mutton Merino) to replace the Dorset Horn in the winter rainfall area as slaughter lamb producers, originated from Mr LH Bartel, who actively occupied himself with the establishment of a slaughter lamb industry for the winter rainfall area.
In the creation of the new breed an effort had to be made to integrate Muellerius cappilaris as far as possible, the excellent mutton qualities and growth rate of the Dorset Horn and the resistance to the lung parasite of the S A Mutton Merino. The qualities of fertility and fecundity, good milk production and a relatively long breeding season are present to a large extent in both these breeds, while both breeds - the one as sire and the other as dam breeding material - have performed best in the previously mentioned cross breeding programmes.
One of the major requisites in the creation of a new breed from a cross is to start off with very good breeding material. It was consequently decided not to utilise the Elsenburg Dorset Horns which were already showing the symptoms of serious lung trouble, but to import good stud rams from Australia.
October 18, 1940 marked the arrival at the Elsenburg Research Station of the ten Dorset Horn stud rams purchased with funds made available by the Council for Control over the Livestock and Meat Industries. Following strict selection on conformation and type, only four of these were selected for eventual use.
As far as can be established the first sale of Dormer rams was held at Elsenburg in 1947 and annually thereafter, except in 1969 when all the sheep were needed for an experiment. The average selling price at the first sale was R15 (approx. US$ 3.2). The price remained relatively low until 1954, where after it started to increase. The highest price for a Dormer ram and the highest average price achieved at an Elsenburg sale was in 1975. At this sale the highest price for ewes and the highest average price during recent years were fetched namely R350 (approx. US$ 74.47) and R276.79 (approx. US$ 58.89) respectively. The first official Dormer sale to be held away from the Elsenburg sales, was at Goodwood on October 27, 1968. Since then sales are being held yearly in Bloemfontein and Goodwood.
Apart from the Elsenburg flock, Dormers were also bred by private farmers. Through participation in the cooperative experiments, farmers and private concerns took part in the breed's development since 1937. Since about 1947 they upgraded their flocks with Dormer rams bought at the Elsenburg sales.