The genetic resistance to gastro-intestinal strongylids in Appenninica sheep: preliminary results.

Heritability parameters of resistance to gastro-intestinal strongylids, measured as FEC (Faecal Egg Count), were evaluated in the Appenninica sheep breed. FEC heritability coefficient was 0.11 +/- 0.061 while FEC repeatability coefficients were 0.58 +/- 0.085 and 0.76 +/- 0.223 in adult females and lambs respectively. Subjects were classified, based on FEC, into three different levels of resistance to strongylids. Ewes belonging to the 'resistant class' should be conveniently exploited in mating schemes, in order to provide a method, alternative to drug administration, for a long-term parasite control; this would result particularly helpful under those production systems, such as organic farming, where the use of drugs is not allowed or limited.