Dormer Manual
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Dormer Manual Revised Edition 2016 1 2 1. THE ESTABLISHMENT AND DEVELOPMENT OF THE DORMER BREED The Dormer is a South African bred white wool mutton sheep developed after years of intensive research at the Elsenburg Agricultural College from the crosses of Dorset Horn rams and German Merino ewes. The purpose of the development of the breed was to breed an early maturing sheep breed that can produce affordable meat at an early age, that would be well adapted to conditions in the winter rainfall area and that could compete with Australian and New Zealand lambs at the Smithfield market in England. The further purpose was to produce suitable rams for cross breeding, especially with the Merino and it was therefore decided to create a white wool mutton breed, free of kemp and coloured fibres. 2. SLAUGHTER LAMB TRIALS AT ELSENBURG Since 1927, for more than 10 years, rams of the following breeds were mated to Merino ewes which were the most readily available at the time: Dorset Horn, Border Leicester, Ryeland, Romney Marsh, South Down, Suffolk Down, (British mutton breeds) as well as Texel, Corriedale, German Merino and Blackhead Persian. Thereafter German Merino X Merino ewes were mated to Dorset Horn rams and it was found that the progeny were heavier than any other cross lambs. The above results gave rise to the mating of German Merino ewes to Dorset Horn rams. In addition to the unique traits of German Merino ewes, they could also, like the Merino and Dorset Horn, easily lamb in the fall with an acceptable lambing percentage. Experiments carried out proved that Dorset Horn X German Merino lambs excelled as slaughter lambs. 3. CO-OPERATIVE EXPERIMENTS IN THE WINTER RAINFALL REGION The excellent results obtained from the Elsenburg slaughter lamb trials gave rise to the decision to carry out similar trials at a cooperative level and to develop it amongst farmers in the region, with the view of establishing a profitable slaughter lamb industry, directed at the overseas market. During 1936 and 1937 a couple of hundred mutton rams were imported from Australia and England and primarily crossed with Merino ewes. In excess of 6000 lamb carcasses were thereafter exported to the Smithfield market. Extensive trials proved the Dorset Horn ram to be the best mutton ram for slaughter lamb production. The small Meullerius lungworm was however causing problems. The Dorset Horn and German Merino studs founded in 1923 and 1932 respectively and which were kept at Elsenburg under similar conditions, could be compared in respect of its susceptibility and resistance to lungworm. It was concluded that the German Merino had 3 a stronger resistance against lungworm and that in the case of the Dorset Horn, it could possibly be hereditary. 4. PLANNING OF THE ESTABLISHMENT OF A NEW BREED Mr LH Bartel who actively strived towards the establishment of a slaughter lamb industry in the winter rainfall region, came with the suggestion that a new breed must be established from the Dorset Horn and German Merino, to replace the Dorset Horn as slaughter lamb producer. Attempts were made to combine the mutton traits and growth ability of the Dorset Horn with the strong resistance against lungworm of the German Merino and to fuse it into the proposed new breed. Both breeds possessed the much sought after characteristics of high fertility, fecundity, milk production and an extended breeding season. On 18 October 1940 ten Dorset Horn rams were imported from Australia, sponsored by the Control Board for the Sheep Stock industry. Subsequent to strict screening on conformation and type, only four rams were selected to be mated to stud and grade German Merino ewes at Elsenburg. Only the two top performing rams were used in the subsequent mating season. No further cross breeding of Dorset Horn X German Merino were done subsequent to 1941. The first generation (F1) ram and ewe lambs were to serve as basic material for building the new breed. 5. PROGENY TESTING OF RAMS Rams render the most significant contribution towards the improvement of a flock and for this reason it was decided to first test the F1 ram lambs prior to using them in the new flock. In 1941 eight of the best F1 ram lambs representatives of the said four Dorset Horn rams were selected. At 7 months they were each put with 20 grade German Merino ewes for the purpose of mating. In this way their breeding value for slaughter lamb production could be determined. The main selection criteria from the outset were an early maturing slaughter lamb with excellent conformation. The best two rams from the initial eight were then identified for use in the flock on account of their breeding performance with regard to growth, carcass quality, grading, fat distribution, conformation and lung worm resistance. To avoid inbreeding it was agreed to mate F1 rams, the progeny of ram no. 4, with selected F1 ewes of ram no. 37 and vice versa. Attempts were made at all times to avoid close inbreeding. 4 6. EXCELLENT BREEDING PERFORMANCE Notwithstanding a considerable workload and substantial record keeping the testing of young rams on grade ewes prior to being used in the flock was maintained for many years and generations. The new breed was less susceptible to lungworm – thanks also to research that was carried out on the lungs of lambs slaughtered for progeny testing. Results obtained from cooperative trials and farmers in the winter rainfall area proved that the breed was convincingly suited to the winter rainfall region and that, in a cross breeding program, it will produce the type of slaughter lamb sought after by breeders. Mr LH Bartel, the architect of the new breed, passed away in 1944 upon which this project was passed on to Mr JF du Toit. He in turn passed away in 1947 where after Mr IL Ferreira took over. Mr Ferreira was the master builder of the breed and until his retirement in 1981, he executed this task with loyalty, purposefulness and in an ever-humble fashion. After 25 years of careful record keeping, strict selection, unsurpassed dedication, production recording and without introducing any new or foreign blood, the breed traits and type were established to such an extent that the Dormer was in 1975, after seven generations, registered with the SA Stud Book as an independent breed. 7. DORMER TODAY Although the Dormer was primarily bred for use in the winter rainfall region, it proved to be highly adaptable to other regions and is therefore being used in all regions of South Africa for slaughter lamb production. In an attempt to promote and improve the breed, courses are regularly being presented and breeders participate at shows and exhibitions as well as slaughter lamb competitions. The National Dormer sale takes place annually during September in Bloemfontein. Stud breeders are compelled to participate in production recording and the Dormer Society was the very first to rule that only production recorded animals may be sold at the National Dormer Sale. 8. THE DORMER HOLDS ALL THE ECONOMICALLY IMPORTANT TRAITS TO BE CATEGORIZED AS THE IDEAL MUTTON BREED 8.1 CONFORMATION The ideal Dormer is an energetic, smooth bodied, white woolled sheep with good muscling, good length, width, and depth, well 5 filled hindquaters, well developed loins, strong topline, a head displaying good character, with strong bones and well pigmented eyelids, with stong well places legs, strong pasterns and healthy hooves. The animal should stand reasonably high for ease of movement. 8.2 FERTILITY AND UNLIMITED BREEDING CYCLE Fertility is one of the breed’s strong points and breeders specifically select for multiple births. Twins are preferable although triplets are common; quadruplets, quintuples and even sextuplets have been recorded. A lambing percentage of 150% and higher is quite common (lambs born in comparison with ewes mated). Large numbers of surplus lambs ensure the profitability of the industry. This also broadens the selection base which in turn speeds up genetic improvement. The unlimited breeding cycle facilitates more than one harvest per year and the lambing season can be managed in order to utilize maximum pastures. 8.3 MOTHERING TRAITS, MILK PRODUCTION, GROWTH RATE Outstanding mothering traits ensure a high growth rate and weaning percentage. Dormer lambs generally maintain an average daily gain of 400gr up to 100 days, but gains of up to 500gr are not uncommon. The weight of the lamb at 42 days is a true reflection of the milk production of the dam while the mass from 42 - 100 days indicate the inherent growth ability of the lamb. 8.4 EARLY MATURITY Early maturity ensures a slaughter lamb ready for market at an early age which produces a quality carcass of 16 – 22 kg at 3 months. This characteristic is also sought after where cross breeding is done for slaughter lamb production with late maturing breeds such as the Merino. The benefits of early maturity are that lambs may be marketed at an early age, that ewes can be rested more often and can produce more wool, that more ewes can be kept per hectare and that it is only necessary to carry mature animals when pastures are poor. Young ewes are able to lamb from 12 – 18 months which results in an increased turnover and which limits the generation interval. 6 8.5 SLAUGHTER LAMB PRODUCTION AND CROSS BREEDING Outstanding conformational traits, carcass qualities, early maturity, growth speed, fertility, mothering abilities, milk production, unlimited breeding cycle and its ability to adapt puts the Dormer first as the ideal breed for slaughter lamb production. Because the Dormer is able to transfer its conformational traits to late maturing breeds and the relatively small lamb at birth, this breed is very well suited to cross breeding with other breeds.