The emergence of AH multiresistant GIN compromises sustainability of grassland sheep farming worldwide. Plants rich in condensed tannins are an alternative method of parasitism management that is currently being explored. Feed supplementation trials with pellets rich in sainfoin (Onobrychis viciifolia) and quebracho (Schinopsis spp.) were carried out. Three meat sheep farms in western France took part in the study and a total of 4 trials were carried out.

During these 21-day trials, the ewes were returned to the sheepfold and half of them received a balanced ration supplemented with 70 g day−1 of healthy hay and quebracho pellets, while the other half received the same ration supplemented with 70 g day−1 of lucerne pellets. Fecal egg counts (FEC) were carried out at the start and end of each trial, and nematode species were identified by real-time PCR after larval culture. At D0, FEC were similar in both groups for all 4 trials. Proportions of species infecting the ewes varied from 1 trial to another: Haemonchus contortus was predominant in summer and Trichostrongylus colubriformis in winter. At D21, there were no significant differences in FEC between groups. Helminthofauna were not significantly different between groups, except for 1 trial where the proportion of H. contortus was reduced in the group supplemented with condensed-tannin pellets. The use of condensed tannins still requires additional studies to be advised as an effective method to manage gastrointestinal nematodes in farm.

In an effort to identify a forage legume with condensed tannins (CT) that reduce gastro-intestinal nematodes (GIN) in small ruminants without negative effects on nutrition, the following trial looked at the effects of two legumes containing CT on average daily gain (ADG) and faecal egg counts (FEC) in kid goats. Lespedeza cuneata (sericea lespedeza, SL) and Desmodium paniculatum (panicled tick-clover; PTC) were pelleted into isonitrogenous complete feeds containing 3.8% CT in a four week feeding trial. Compared to the alfalfa (Medicago sativa) control diet, SL decreased (P ≤ 0.05) feed efficiency and ADG while PTC had the same (P > 0.05) feed efficiency as alfalfa. The SL and PTC pelleted feeds increased (P = 0.006) daily feed intake by 4.5 kg and 3.7 kg, respectively, compared to alfalfa control, while kids consuming SL and PTC showed an average 44% reduction (P ≤ 0.05) in FEC compared to those fed alfalfa. The results showed that feeding PTC, an herbaceous, perennial legume native to much of North America, to goats may provide a natural means of reducing ruminant GIN while simultaneously providing a source of protein.