Counts of eosinophils and globule leucocytes were not normally distributed, were transformed as ln(count + 1), and were analysed using the general linear models procedure of SAS. The model included fixed effects of breed, group (infection status by day of sacrifice, with two infected and three control groups) and breed by group interaction. Results are presented as back-transformed means and SE. Serum
immunoglobulin concentrations were analysed within infection status using the model used for the repeat-measures analysis of variance of FEC and PCV. RGFP966 nmr Lymph node IgE concentrations at sacrifice were analysed using the model applied to the abomasal cell counts. Simple correlations (r) were calculated between measurements taken in infected animals at sacrifice at 3 and 27 days p.i. (i.e. in the presence of larvae and adult worms respectively). Reported correlation coefficients differed from zero (P < 0·05) unless stated otherwise. No parasite eggs were seen in the
faeces of control animals throughout the study, but all experimentally infected lambs had measurable FEC by 16 days p.i. (Figure 2). The mean FEC of wool sheep was similar to that of hair sheep on day 16, but was 2·8-fold higher at day 21 (3647 ± 770 vs. 1280 ± 867 respectively), and 2·5-fold higher at day 27 (3136 ± 1599 selleck screening library vs. 1267 ± 837) than that of wool sheep (P = 0·12 when mean FEC were averaged across days 21 and 27). Abomasa of control sheep were free of adult H. contortus, whereas worms were present in all challenged sheep. On day 27 p.i., the mean number of adult H. contortus in infected hair sheep (2491 ± 753) was lower (P = 0·07) than
that in wool sheep (4535 ± 690). Lower worm counts were correlated with higher PCV (r = −0·53, P = 0·08) and lower FEC (r = 0·71, P = 0·01). The average PCV of control hair (36·3 ± 0·7) and wool (35·5 ± 0·5) sheep were similar and did not differ between days. However, infection was associated with lower PCV in both breeds at days 16 and 21, followed by an increase in PCV in both breeds at day 27 (Figure 2). In infected animals, PCV were next higher in hair compared with wool sheep; this difference approached significance (P < 0·10) at day 21 p.i. The day of peak FEC corresponded to the time of lowest PCV and FEC and PCV were negatively correlated (r = −0·78, P = 0·07). Breed differences in abomasal lymph node weight were not observed in control animals, but lymph nodes from infected hair sheep were heavier than those of infected wool sheep (P = 0·04, Table 1). Lymph nodes of infected animals of both breeds were likewise heavier (P < 0·001) than those of corresponding control animals. Lymph node weights at sacrifice were favourably associated with PCV on days 0 (r = 0·58), 16 (r = 0·61) and 21 p.i. (r = 0·56).