Is gastrointestinal strongyle faecal egg count influenced by hour of sample collection and worm burden in goats?

Gastrointestinal (GI) strongyle infections remain one of the main constraints to goat production worldwide. Although several indicators of GI strongyle infections have been proposed, faecal egg count (FEC) techniques are the most common approaches for the estimation of prevalence and intensity of these parasites. However, FEC may be subjected to a within-individual variation due to factors such as weather, season, random day-to-day variation and phase of the parasitic infection. A longitudinal study of GI strongyle FEC was conducted on 63 dairy goats to evaluate the effects of hour of sample collection on FEC and the relationship between FEC and worm burden. The goats were naturally infected with Teladorsagia circumcincta, Haemonchus contortus, Trichostrongylus colubriformis and Oesophagostomum venulosum. Every 3 weeks for 14 months faeces were collected every 2 h for 24 h from three individually caged goats. The faeces were those passed by the goats during the 2 h preceding each collection. For each goat a sample from this material was analyzed using the Flotac double technique. To explore relationships between FECs and adult parasite counts, on the day following sampling, the three goats were euthanized and the nematodes present in the abomasa and intestines were recovered, identified and counted. The results of the general linear model did not show any significant effect of the hour of faecal sample collection on GI strongyle FEC, whereas a significant effect of the month of faecal sample collection was found. The results of the Pearson correlation showed a significant (P=0.000) positive relationship between FEC and worm burden (r=0.6), in particular regarding H. contortus (r=0.9). In conclusion, the present study showed that the hour of sample collection does not influence the GI strongyle FEC and that there is a good relationship between FEC and total GI strongyle worm burden in goats.