Genetic diversity and pedigree analysis of the Finnsheep breed1

Abstract

Genetic diversity in the Finnsheep breed was analyzed by quantifying the demographic trends, the depth of known pedigree, effective population size, and the amount of inbreeding, as well as identifying candidate rams within the current population for future breeding and conservation purposes. Pedigree records of 148,833 animals with a pedigree completeness coefficient > or =0.60 and born from 1989 to 2006 were used to estimate the parameters. Mean inbreeding coefficient increased by 0.10% (P < 0.001) and 0.15% (P < 0.001) per annum in all animals and breeding (i.e., reproducing) animals, respectively. Average relationship coefficients among rams, among ewes, and between rams and ewes in breeding animals increased over time and reached 1.67, 1.45, and 1.46% in the 2005 cohort, respectively. The average for breeding rams was above the other 2 averages in almost all birth years. The observed generally low average relationship coefficients between rams and ewes indicate that no extra restrictions on the use of the breeding animals are needed in the near future. Average generation interval was 2.85 yr in the studied period, and the effective population size was estimated to be 119 and 122 using different methods. Relationship coefficients of rams with other breeding rams and rams with breeding ewes are suggested to aid in situ and ex situ conservation decisions on maintaining genetic diversity of Finnsheep.