Table 1.

Monte Carlo simulation estimates of the mean maximum faecal egg count (faecal egg counts (eggs per gram of faeces) and mean faecal egg counts over the course of the peri-parturient rise (PPR; in faecal egg counts, epg) for high (nematode susceptible) and low (nematode resistant) estimated breeding value ewes on two farms in southwestern England, the proportionate reduction in mean faecal egg counts and max faecal egg counts in low EBV ewes compared with high estimated breeding value ewes, and the proportion of simulations where the simulated means for low estimated breeding value ewes were lower than for high estimated breeding value ewes.

		Low EBV	High EBV	Proportion reduction in FEC (1-Low EBV/High EBV)	Proportion simulations where lowEBV ≤ highEBV
Farm 1	Peak FEC (S.D.)	646 (438)	918 (796)	0.296	0.894 (P = 0.106)
	Mean FEC (S.D.)	300 (236)	391 (245)	0.233	0.866 (P = 0.134)
Farm 2	Peak FEC (S.D.)	297 (283)	472 (368)	0.371	0.967 (P = 0.033)
	Mean FEC (S.D.)	168 (137)	255 (203)	0.341	0.954 (P = 0.046)