Samples consisting of 1 262 and 2 291 pedigrees were employed in the analysis of the breed structure of the S.A. Mutton Merino for l961/62 and 1971/72 respectively. The breed structure was not stabilised in either analysis since the first importations of German Merinos occurred only 40 years previously. However a definite hierarchy was already apparent in the genetic structure of the breed while genetic material from the upper strata could filter down rapidly to the lower strata. Although 48 studs were classified as “breeders’ studs” in 1971/72, only 22 of these provided rams in effective numbers to the stud industry according to a numerical description of the breed structure. The flow of genes from the appendix register to the stud industry decreased rapidly during the decade after 1961/62 as a result of the discontinuation of Appendix A in 1954. Furthermore, less than 2% of-the studs used imported sires in l971/72 while in l96l1/62 the corresponding figure was almost 20%.
"Experientia docet" - Experience is the best teacher