Correlation of Faecal Egg Counts with Clinical Parameters and Agreement between Different Raters Assessing FAMACHA©, BCS and Dag Score in Austrian Dairy Sheep

SIMPLE SUMMARY: The objectives of this study were to evaluate the associations between the faecal egg count for strongylids and the clinical parameters in lactating dairy ewes. In addition, the agreement of three raters regarding the clinical examination was assessed. For this purpose, a total of 1195 dairy ewes from 16 farms were included. FAMACHA©, BCS and dag scores were determined and a Mini-FLOTAC was performed on individual samples, which were then pooled for larval culture at the farm level according to the number of lactations. Trichostrongylids were found in 95% of the investigated samples. The BCS was negatively correlated with the faecal egg count, while the FAMACHA© score showed a slightly positive correlation. The dag score did not show significant associations. A minority (25%) of the flock shed the majority of eggs (47% to 84%). It was concluded that clinical scoring does not allow us to extrapolate to faecal egg excretion. The agreement was moderate to good between different raters, showing that training on clinical parameters is recommended for assessment in sheep. From a clinical perspective, both faecal egg counts and clinical parameters should be used simultaneously as separate tools to detect major egg shedders (contaminating the pasture) and sheep suffering from strongylidosis. ABSTRACT: Gastrointestinal nematodes, most notably trichostrongylids, are known to cause significant losses in sheep production. Previous studies have shown that monitoring parameters (e.g., FAMACHA©, BCS, dag score) change with increasing egg excretion. These parameters are well known and frequently used for targeted selective treatment. Based on the willingness to participate in this study (based on a previous questionnaire distribution among sheep farmers in Austria) we investigated the associations between faecal egg counts and the FAMACHA©, BCS, and dag scores of 1195 dairy ewes. Faecal samples were analysed using the Mini-FLOTAC technique I and larval culture. Three raters assessed the FAMACHA©, BCS, and dag scores in sheep to calculate the inter-rater agreement and intraclass correlation coefficient. The responses to the questionnaire of 23 farms were used for the evaluation, of which 16 farms were visited. Trichostrongylid eggs were detected in 95% of the faecal samples. The BCS was negatively correlated with the eggs per gram of faeces (EpG) (r = −0.156; p < 0.001) and the FAMACHA© score was slightly positively correlated with EpG (r = 0.196; p < 0.001). A small proportion of sheep (25%) shed the majority of eggs (47% to 84%). A moderate to good agreement for the parameters was found between the raters. In conclusion, the clinical parameters showed only weak correlations with faecal egg counts, and we confirmed that a minority of the flock is responsible for the majority of the pasture contamination with trichostrongylid eggs. Clinical raters should be trained before a study to increase the agreement between them.