Correlation Among Traits
Canadian researchers conducted a study to determine the relationship between (log transformed) fecal egg counts (FEC) and packed cell volume (PCV) and subjective clinical parameters, including FAMACHA© score, body condition score (BCS), dag score (DS), and fecal consistency score (FCS), in a cold, continental climate in which Haemonchus makes up only a moderate portion of the parasite infection. Data was collected in spring (April) and summer (August) from 21 farms in Ontario and 8 farms in Quebec.
Results from simple correlations indicated that PCV was negatively correlated with FEC (r=0.255, +/- 6.5%) and FAMACHA© (r=0.312, +/- 9.7%) and positively correlated with BCS (r=0.317, +/- 10%). FEC was negatively correlated with BCS (-0.232, +/- 5.4%), but positively correlated with FAMACHA© (r=0.178, +/- 3.2%) and DS (r=0.086, +/- 0.7%).
While correlations were significant, none were high enough for clinical parameters to be accurate predictors of FEC or PCV. Of all the clinical parameters, body condition scores accounted for the most variation in the PCV model.