- The supply of Genetic Material by Angora Goat Studs to the Commercial Industry
|Last update: March 30, 2012 09:23:44 AM|
The supply of Genetic Material by Angora Goat Studs to the Commercial Industry
G. J. Delport, S.A. Fleece Testing Centre, Middelburg, Cape
Apart from within flock genetic improvement, interchanging of superior genetic material between flocks could make a vast contribution to the genetic improvement of any race of farm animals. Unfortunately most farm animals in South Africa are being sold solely on the basis of their phenotypic superiority (visual appearance) and in that way being exchanged between breeding units (e.g. studs and commercial flocks). It is also a well-known fact that environmental differences between different breeding units contribute a large proportion of the phenotypic differences within any group of animals originating from different farms. It follows as a matter of course that an individual animal's visual appearance is not always a true indication of how that specific animal will ultimately breed.
The above-mentioned problem can naturally be overcome by comparing animals from different breeders in the same environment (e.g. at bull testing stations or ram testing stations). An alternative possibility would be to compare the genetic merit of different flocks in a specific race to a genetic control flock. Should such relative sophisticated tests not be available a potential buyer should, however, rely on his own judgement as to which breeder he purchases his rams from. A good practice in this case would be to investigate which breeders practise accurate selection. With the implementation of within flock performance testing for registered Angora goat breeders in 1982 one can expect more accurate selection in the breeding units concerned.
The aim of this article is to determine the number of rams supplied to the commercial industry by registered Angora goat breeders against the background of the above-mentioned fact.
Number of rams required by the Angora Goat Industry
The following statistics and assumptions were used in this calculation:
According to the official estimate of the Mohair Board there was a total of 1,3 million Angora goats in South Africa in 1979. To calculate the number of Angora goat ewes statistics of the Mail-in Record Study Group of the Karoo Region from 1972 to 1980 was used. The total number of Angora goat ewes in 1979 was estimated as 0,643 million by using the estimate of 49,6070 ewes per flock from these records.
With the assumption that one ram was mated to 30 ewes it was subsequently calculated that the total number of rams required was 21 500. To estimate the yearly requirement of rams, the yearly replacement of rams on a percentage basis must be known. By using the percentage of rams identified as replacements in the stud industry in 1979 as parameter this figure could be estimated as 34,4%. By taking into consideration the large number of ram age groups (± 7 to 8) the studs it seemed as if the replacement of 34,4070 was an over-estimation. This over-estimation could be ascribed to economic factors in the short term, for example relatively high Mohair prices. Although the figure of 34,3% is correct for the current economic condition the figure of 20% (estimated according to the number of ram age groups) would be a better indication of the long-term tendency.
The total number of Angora goat rams was subsequently estimated as 4 300 in 1979 according to the long-term tendency of ram replacements. Taking into consideration the economic climate in the short term, a figure of 7 400 was estimated. These facts clearly reflect the great demand for rams at this stage.
Percentage of the total ram requirement supplied by registered studs
According to the available records the total number of rams supplied yearly to the commercial industry by studs was estimated as 2 900. This figure included replacements in studs (56 rams), stud ram sales (600 rams), flock ram sales (267 rams) and on farm sales (1 961 rams). It was subsequently calculated that the registered breeders supply only 39,2% of the total ram requirements in the short term. The more realistic figure of 67,4% was calculated on a basis of long-term figures.
According to the yearly kid returns of the Stud Breeders' Association 3 800 ram kids were produced in 1979. By assuming a mortality of 5% over the period between submitting the kid returns and the sale of these young rams it was calculated that only 20% of the total production of rams was culled.
The situation as illustrated above implies that registered breeders do not produce a sufficient number of rams to supply the current demand for rams. Taking into account the low percentage of rams (20%) which were culled in studs the rams supplied to the commercial industry can be regarded as a random sample taken out of the stud industry. It is evident that a larger stud industry in relation to the commercial flocks was necessary to supply more rams of superior quality.
The fact that the stud industry cannot supply the total demand for rams imply further that unregistered breeders and commercial Mohair producers who breed their own rams control a significant proportion of the demand for rams. This fact emphasizes the responsibility of the stud industry to supply superior genetic material in order to stay in control of the total industry. Accurate selection on the basis of objectively measured characteristics of economic importance is fundamental in genetic progress and thus also in retaining the position of the stud industry in the breed hierarchy.