Crossing indigenous goats with a larger imported breed increases vulnerability to natural infection with gastrointestinal strongyle parasites

•Resistance to gastrointestinal nematode parasites was compared in Sri Lankan goats•Indigenous goats were compared to crosses with larger imported Jamnapari goats•During the dry season, Jamnapari crossbreds had somewhat higher fecal egg counts•Jamnapari crosses also had much greater within-herd variation in fecal egg counts•A subset of the Jamnapari crosses therefore had strongly elevated fecal egg counts