- Crossbreeding and Production of Fat-Lambs
|Last update: April 11, 2012 03:38:59 PM|
Crossbreeding and Production of Fat-Lambs
G. J. Schuurman
SHEEPFARMING in the Union has hitherto been confined chiefly to the production of wool, while it has constantly been the policy of the Department to improve the Merino sheep. Consequently our Merino wool has, during the last 15 years, improved to such an extent as to secure a firm footing on the European market.
Although Merino, Blackhead-Persian and fat-tail hamels - not to mention old ewes - have hitherto been absorbed by and realized good prices on the local market, the increase in our Merino sheep has now reached a point of surplusage, and we are therefore definitely faced by the necessity of exporting our mutton.
Such an export trade will undoubtedly be encouraged by the legislation recently passed, in accordance with which export meat will be subsidized. (The relative regulations appeared in the Government Gazette of June 23.)
The crossing of Merino sheep with any pure-bred mutton type has never been encouraged, as there is always the danger that farmers may use such cross-bred lambs in the breeding of woolled sheep, and that would be unfortunate for the good name of our wool, which has taken us years to build up. It is complained in wool circles that our Merino wool in comparison with that of Australia contains too large a percentage of black and coloured fibres. For this reason much of our finest wool is not used in the manufacture of pure-white men's and women’s underwear. Our Merino wool has, however, improved considerably in colour and general quality over the last few years, and our Merino sheep farmers should guard against any deterioration in the quality of our wool as a result of indiscriminate crossbreeding. For example, if Merino sheep were crossed with the British short-woolled mutton breeds or Blackhead-Persians and other indigenous mutton types, the wool of the progeny would be worthless in comparison with Merino wool, as it usually contains black and coloured wool fibres, hairs and kemp. Where the farmer goes in for such a cross, he should sell also his ewe lambs and-not keep them for breeding purposes.
Although there has been a considerable decline in the price of Merino wool, it is nevertheless the general opinion that as soon as world conditions improve wool will be one of the first products to recover in price. Sheep farmers in the premier sheep area of South Africa (such as the best parts of the Karoo, and mixed-veld and sweet-grass areas) where Merinos answer exceptionally well, would be well advised not to go in for cross-breeding, but rather to improve their Merinos where possible. Their ideal should be a plain-bodied Merino sheep producing a medium-fine wool. Although this sheep area is more or less subject to periodical droughts and has a carrying capacity of 1 to 3 morgen per sheep, it is nevertheless eminently suitable for Merino sheep farming on a big scale. It would, however, not be suitable for the breeding of fat-lambs, except in such parts where there may be sufficient land under irrigation for the growing of fodder crops.
In the matter of sheep suitable for export, it may be pointed out that the mutton of fat-tail sheep does not conform to the requirements of the trade, and that the position in regard to Merino hamels and ewes is doubtful. We should therefore confine ourselves almost exclusively to the export of fat lambs.
Therefore, it is considered advisable to furnish a brief description of the lines on which such crossbreeding should, in the opinion of the Department, take place. It is the Department's intention to carry out a fresh series of crossbreeding experiments and, on completion of these, and in accordance with the results obtained, to advise sheep farmers as to the crosses to be adopted or avoided.
The breeding of fat-Iambs should not be regarded merely as a temporary expedient, as there are parts of the country better suited to this class of farming than to wool-growing.
The fact should also be emphasized that the production of fat-lambs is a specialized class of farming, and that the farmer who wishes to make a success of it should give it his full attention. It is a class of farming that fits in well with mixed farming.
Requirements of Fat-Lamb Production
One of the main requirements in this connection is the production at the right time of a sufficiency of the right kind of feed, so that the ewes shall give milk in abundance, thus ensuring the rapid development of the lambs. The latter should, if accorded the correct treatment, be in first-class condition for the market within 20 weeks. The lambing season should be so regulated that when the ewes start to lamb there shall be an abundance of pasture and green feed on the farm. This class of farming is thus best suited to small farms where sufficient feed (green forage especially) can be produced, or where the natural grazing is good and plentiful and, furthermore, where other natural conditions, such as climate, etc., is favourable. It can only be made a success where: (a) the farm is situated in an agricultural area with a good annual rainfall, such as (1) the grain districts of the western and eastern Cape Province, and (2) the maize districts of the Transvaal (notably the eastern Transvaal), the eastern and north-eastern Orange Free State, parts of Natal and Griqualand East, (b) the farm is under irrigation.
Crossbreeding with the Merino as Foundation
a. Triangular crosses
In countries such as Australia and New Zealand, where the breeding of fat lambs is an extensive industry, the Merino ewe is used for a first cross in the breeding of the mother stock (dam). The plain-bodied Merino ewe being crossed with one of the British breeds (Border-Leicester, Romney, Lincoln, etc.), and the female progeny thereof again crossed with one of the British mutton breeds. (Downs, Dorset Horn). The lamb resulting from this triangular cross is the fat-lamb of the export trade. The advantage of this cross is that the resultant ewe lamb (British long-wool x Merino) makes a better dam than does the ewe of the plain-bodied Merino, and that such a lamb is of better quality and sooner mature than the lamb of a first cross with the plain-bodied Merino. Furthermore, such ewes produce a considerable quantity of good wool, the spinning quality of which is; however, lower than that of Merino wool. This "triangular" method of crossing is merely touched upon here, as there is a possibility that it may be employed at some future time in this country. It is, however, a matter or time, and at the moment it would be less economical to breed first the British long wool x Merino dam as it would be impossible to obtain such dams here in sufficient numbers.
b. First crosses
For the near future a first cross with plain-bodied Merino as dam, is recommended. There is, however, a tendency today to use all culled ewes for crossbreeding. This is wrong in principle, as many Merino ewes are culled and disposed of on the score of smallness, defective conformation, excessive fold-development, and a weak constitution. There is a vast difference, so far as early maturity, quality of the mutton, milk production and fertility are concerned, between the sturdy, plain-bodied Merino ewe and the puny, badly built and foldy type. Consequently, Merino ewes should be carefully selected, and only those that possess the best mutton qualities and are plain-bodied should be used for crossbreeding. It would pay Merino sheep breeders to breed the desired type of ewe. The early maturity, mutton qualities, milk production and fertility of the German Merino mutton sheep have been improved to such an extent in Germany that the breed is regarded there as being productive of one of the best types of dam. As the German Merino mutton sheep is practically purebred and produces Merino wool, it would certainly be an asset to this country. By crossing a ram of this breed with our Merino ewes, good Merino wool producers and good dams would be obtained. In other countries where farmers confine themselves to the breeding of fat-lambs, wool-producing, dams are preferred to the pure-bred mutton breed of dam, as the wool of the former is always an additional source of income.
The following are possible crosses, with the plain-bodied Merino as dam (mother stock): -
(1) With Border Leicester, Romney, Corriedale, Texel and German Merino mutton sheep rams. - Excepting the last-named, all these breeds are long wool types, i.e. woolled sheep producing a good quality wool, of which the spinning qualities are, however, lower than those of Merino wool. The female progeny of these crosses would make good dams where the farmer contemplates employing "triangular" breeding methods. The hamel lambs resulting from such a cross could be sold either as fat-Iambs or young hamels. In the latter case the income derived from the wool would compensate the farmer for keeping the lambs so much longer on the farm.
(2) With British Down Rams (such as South Downs, Suffolk Downs, Shropshires, Hampshire, Oxford), which are all excellent, early-maturing breeds. Their wool is, however, not worth much, as it contains a large percentage of black and grey fibres. The ewe lambs of such a cross should therefore be slaughtered before they reach maturity.
(3) With Dorset Horn and Ryeland Rams. - These two British mutton breeds are also early maturing, while the wool of both is of a good colour, although that of the Dorset is of very poor quality. Good results have been obtained by experimental crosses with the Dorset Horn ram, more especially in view of the fact that this breed is the most suitable of all the British mutton breeds for the breeding of early autumn lambs.
(4) With Blackhead-Persian rams. - This is a cross, which sells well on the local market. It will be possible, by means of experimental shipments, to determine whether or not the fat-lambs of such a cross will sell well on the overseas market. As both breeds of this cross are abundantly available and obtainable at reasonable prices, it will be possible, forthwith, to produce fat-lambs cheaply and in large numbers by this means. It is, however, doubtful whether this cross will mature early enough to be of success in our intensive farming proposition.
Indigenous Mutton Breeds
Our indigenous mutton breeds, such as the "Roundrib Afrikander ", Namaqua, Native sheep and crosses of these (which may conveniently be designated "fat-tails ") as also the Blackhead-Persian (which, as a matter of fact, is not an indigenous breed) are the only breeds of sheep that answer well in the drier parts of our country, such as the north-western Cape Province and the bushveld of the northern Transvaal. There this class of farming is extensively carried on and it has already been shown by means of experiments that a cross with the Blackhead-Persian is under such conditions, the best. Further grading up with Blackhead-Persian is strongly recommended.
These sheep are not only hardy against drought, but also resistant to diseases such as bluetongue and heart-water. They are prolific and under favourable conditions the ewes lamb during any season of the year. These are all important factors, and under certain conditions the ewes or these sheep will probably make better dams than the ewes or our plain bodied Merinos.
Experimental shipments of Blackhead-Persian and Blackhead-Persian x Native sheep lambs have already been sent to England but, as is readily understandable, the British public does not favour fat tails or too much fat on the rump, for which reason the tails and superfluous rump fat should be removed from the carcasses before they are shipped. The reports on these shipments were favourable, but It better class of fat-lamb could undoubtedly be bred by crossing Blackhead-Persians and fat-tails with a British mutton breed. However, to avoid any difficulties in the lambing, only the large ewes of these breeds should as dams, be mated with the British mutton breeds.
Under a system of intensive farming that is to say, where farms have sufficient land under irrigation for the growing of fodder crops, or in parts where the above-named class of dam answers well, the lamb of a cross with one of the British mutton breeds will be suitable for export. Perhaps a second cross back to the British mutton breed would answer, the purpose even better, but this can only be determined by further experiments. Under a system of semi intensive farming, that is to say, where the farm is small and the grazing exceptionally good, the lambs of the first cross will, during favourable years, be good enough to market.
For the breeding of fat-lambs, with the Blackhead-Persian or fat-tail as dam, the following crosses are recommended: -
(1) For extensive farming, crosses or grading up with a Blackhead-Persian ram.
(2) For semi-intensive farming, where under normal conditions the natural grazing is exceptionally good, crosses with British mutton breed rams (Downs, Dorset Horn, Ryeland, Welsh Mountain).
(3) For intensive farming and with land under irrigation, (a) crosses with British mutton breed rams (Downs, Dorset Horn, Ryeland), (b) 1st cross ewes of (4) above, crossed back with British mutton breed rams.
The Department is at present conducting some of the above-described experiments, and will commence with the remainder as soon as the necessary imported rams arrive. At the outset the public will have difficulty in procuring rams, as described above, for cross-breeding purposes; consequently some time must necessarily elapse before we can be in a position to breed fat-lambs on a large scale.
Farming in South Africa 7