This work is an application of several techniques of genealogical analysis to the line Torbiscal, produced by blending four old strains of Iberian pigs from Alentejo (Portugal) and Extremadura (Spain). The complete genealogy, with 3489 breeding animals descending from 116 founders, was used to estimate the recorded changes in the period 1963-97, for the following parameters: (i) genetic contributions of the founder strains, with present values 26.9, 14.5, 23.4 and 35.2 per cent; (ii) expected number of founder alleles of these strains, with present values 2.6, 1.7, 2.3 and 3.4 survival alleles; and (iii) partial inbreeding coefficients ascribable to every strain, with mean present values 3.9, 1.7, 3.4 and 5.3 per cent, for a total mean inbreeding of 14.4 per cent. The highest values are found in the strains belonging to types practically extinguished (Ervideira, the golden pig from Alemtejo or Puebla, the hairless black pig from Guadiana valley), which points out the interest of Torbiscal line as a reservoir of the genetic legacy of Iberian pig.