Effect of sainfoin (Onobrychis viciifolia) and faba bean (Vicia faba) on the periparturient rise in ewes infected with gastrointestinal nematodes

Previous research has demonstrated the potential of tanniniferous feed sources to reduce the faecal egg count (FEC) of sheep and lambs infected with gastrointestinal nematodes (GIN). The present study investigates the use of sainfoin (Onobrychis viciifolia, cv. Perly) and faba bean seeds (Vicia faba, cv. Scirocco), either as single condensed tannin sources or in combination, to reduce the periparturient rise in the faecal egg count of GIN-infected ewes. Seventy-eight periparturient Red Engadine ewes (PP ewes) and fifteen ewes of the same breed in early gestation (EG ewes) were used for the study. All animals experienced an artificial infection with 1500 infectious larvae of Haemonchus contortus 33 days prior to lambing. For a feeding period of 25 days, PP ewes were allocated to four groups that were balanced with regard to FEC, number of foetuses and age. PP ewes were fed with either (i) a ryegrass-clover forage, C (n=21); (ii) a sainfoin forage, S (n=19); (iii) a combined condensed tannin feed consisting of sainfoin forage and faba bean pellets, SB (n=19); or (iv) faba bean pellets and ryegrass-clover forage, B (n=19). The diets of PP ewes were supplemented with commercial concentrates to balance the protein and energy intake between groups. EG ewes were used to determine the dimension of the periparturient rise in groups i–iv. During the 25 day feeding period, faecal sampling took place every third or fourth day. Individual FECs were expressed per gramme faecal dry matter (FECDM). Compared to the control group (C), the differences in FECDM over the entire feeding period were −54.7% (S), −40.0% (SB), +7.8% (B) and −41% (EG). A mixed model analysis revealed significant differences between the C and S groups (p