Gastrointestinal nematode egg counts throughout the reproductive cycle of breeding ewes: Relation to body condition, FAMACHA© and dag scores

Sheep flocks in Galicia (NW Spain) have a high prevalence of gastrointestinal nematodes (GIN), and effective control of these parasites is of primary concern. As young lambs in these flocks are generally marketed immediately after weaning, control strategies target the breeding ewes. The aims of this study, involving ewes from two commercial flocks, were as follows: 1) to investigate the dynamics of GIN infections, as determined by faecal egg count (FEC), throughout the reproductive cycle, and 2) to assess the reliability of body condition score (BCS), dag score (DS), and FAMACHA© score (FS) as indicators of infections with a high FEC (>400 eggs per gram of faeces). Data were analyzed using generalized linear and mixed-effects logistic regression models. A periparturient rise (PPR) in FEC was observed across all lambing seasons (spring, summer, autumn and winter), particularly in ewes with multiple lambs. In spring, summer and autumn, PPR began in the fifth month of gestation or the first month of lactation, while in winter, it began earlier, in the fourth month of gestation. Low BCS (<2.5) and high FS (>3) were associated with elevated FECs. The BCS-FEC association was consistent across both farms, with odds ratios (ORs) of 5.23 (95 % confidence interval [CI]: 2.46–11.12) and 6.35 (95 % CI: 4.06–9.94) on Farm 1 and Farm 2, respectively. FS was strongly associated with FEC on Farm 1 (OR=10.46, 95 % CI: 3.37–32.46) and served as a specific indicator of haemonchosis: high FS values closely paralleled Haemonchus FECs during summer and decreased post treatment. High FS values were not observed on Farm 2, where Haemonchus was absent.