Parasitic gastrointestinal nematodes (GIN) pose a major barrier to profitable organic sheep and goat production. Including birdsfoot trefoil (BFT), a forage rich in condensed tannins, in small ruminant pastures can help suppress GIN infections and reduce the need for costly feed supplements. This project sought to develop and demonstrate pasture planting and management practices to establish and maintain sufficient BFT to suppress GIN and thereby make organic small ruminant production economically viable.

Small plot trials of 12 BFT varieties planted in 2019 and harvested through 2022 showed significant differences in BFT cover, survival, and biomass, with ‘Wellington’ and ‘NB95-120’ giving highest yields. BFT established well in cultivated seedbeds and reached only low% cover when sown into existing pasture, with best results when planted into bunch grasses (orchardgrass, timothy, ryegrass) using 3” sweeps to prepare seed rows. Forage grasses show allelopathic activity against BFT, especially tall fescue and reed canarygrass which may inhibit BFT germination by 50%.

Lambs grazing on pasture with 30-50% BT had higher body condition score and daily weight gain (0.31 lb/day) than lambs on orchardgrass/red clover pasture (0.22 lb/day).  BFT benefits became nonsignificant in 2022, when competition from quackgrass depressed the BFT component to ~5% of total forage biomass.