Genetic variability and population structure of Raeini Cashmere goat breed assessed from pedigree analysis

Pedigree information collected from 1979 to 2012 were used to study the genetic varia bility and population structure of Raeini Cashmere goats, taking kids born from 2009 to 2012 into account as the reference population. The mean inbreeding coefficients in the whole and inbred pop-ulations were computed to be 0.04% and 4.41%, respectively. Considering the reference population, the average inbreeding coefficient and average relatedness were 0.14 % and 0.11%, respectively. The mean of generation interval, computed from four gametic pathways (sire-son, sire-daughter, dam-son and dam daughter), was 3.72 years, with a longer interval from dam-progeny pathways relative to sire-progeny ones. In the reference population, the average equivalent complete generation, as a measure of pedigree completeness, was 1.25. The effective population sizes estimated from the indi-vidual rate in coancestry and from the individual increase in inbreeding were 332 and 229, respec-tively. The effective numbers of founders (fe) and the effective numbers of ancestors (fa) were esti-mated at 240 and 137, respectively. Approximately, 50% of the total genetic variations were ex-plained by the first 57 influential ancestors, with a maximum individual contribution of 3.94%. The ratio of fe to fa, as measure of bottleneck, was 1.75. The results revealed the evidences for occurrence of bottlenecks in the population, mainly because of unbalanced contribution of breeding animals to the gene pool of the studied population of Raeini Cashmere goat.