The breed structure and genetic analysis of the pedigree Sahiwal breed in Australia

Abstract

The breed structure and genetic history of the pedigree Sahiwal breed in Australia were analysed from registration data from the Society's Herd Book. It is stressed that the study is a special case—a new breed founded on 10 imported animals, numerically small, and still in its development stage.

The breed structure was divided into four levels, with 10 imported animals at the top determining the genetic make-up of the breed. The genetic contribution of imported animals to the breed was 73.5%.

Determination of the percentage direct relationship of important animals showed that several animals made a major contribution to the genotype of the breed. The maximum contribution of any one animal was 36.2%. Total inbreeding in 1974 was 21.2%. This comprised 5.6% current inbreeding, 8.3% long-term inbreeding and 7.3% strain inbreeding. The index of subdivision calculated from non-current and long-term inbreeding was 1.88, which indicated that there was little effective subdivision of the breed into separate strains.

The effective generation length was 6 years. There was no selective registration of either sex.