Secondary plant compounds have shown bioactivity against multi-drug resistant Haemonchus contortus in small ruminants. This study screened 51 strains of birdsfoot trefoil (BFT, Lotus corniculatus) crude aqueous extracts (BFT-AqE) for anti-parasitic activity in vitro against egg hatching, and of those 51 strains, 13 were selected for further testing of motility of first (L1) and third stage (L3) larvae, and exsheathment of L3. Proanthocyanidin content ranged between 1.4 and 63.8 mg PAC g−1 powder across the 51 BFT strains. When tested against egg hatching, 21 of the 51 aqueous extracts had an EC50 of 1–2 mg powder mL−1, 70% of the strains were >90% efficacious at 6 mg powder mL−1 and 11 of the strains were 100% efficacious at 3 mg powder mL−1 BFT-AqE. Across the 13 strains tested against L3, efficacy ranged from 0 to 75% exsheathment inhibition, and 17 to 92% L3 motility inhibition at a concentration of 25 mg powder mL−1 BFT-AqE. There was no correlation between the PAC content of BFT powders and the anti-parasitic activity of aqueous extracts, therefore other secondary compounds may have contributed to the observed anti-parasitic effects. Further testing of BFT using bioactivity-driven fractionation and screening of BFT populations for the identified anti-parasitic compounds is needed.

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Tanniferous forages, such as birdsfoot trefoil (Lotus corniculatus L.), are a potential control for the parasitic nematode Haemonchus contortus (barber pole worm). Gastrointestinal parasites cause huge economic loss in small ruminant production. Tanniferous forages have been shown to reduce counts of parasite eggs in feces of small ruminants. Currently the tanniferous forage Lespedza cuneate L. is used in the southern United States in control of gastrointestinal nematodes of small ruminants. It is not a viable option in the Northeast due to insufficient winter hardiness. Birdsfoot trefoil is adapted to the Northeast and may be a viable option as a tanniferous forage for small ruminant production if populations exist that combine anthelmintic efficacy with strong agronomic performance. To address this need, I collected data on the agricultural performance of 51 Plant Introductory (PI) accessions and six commercial cultivars. In a three-year field study (2013, 2014, and 2015) I evaluated growth habit, winter hardiness, pest resistance, uniformity and vigor for 57 populations. In 2015, I tested 19 PI accessions and six commercial cultivars for grazing tolerance, regrowth, and uniformity and vigor in a rotationally grazed pasture trial. Birdsfoot trefoil accessions were chosen for the studies based on condensed tannin contents reported in the literature. Tannin content and in vitro anthelmintic efficacy were compared to agronomic characteristics. Growth habit was assessed using height/width ratios measured once each year. Winter hardiness was assessed as survival rate counted each spring. Birdsfoot trefoil is susceptible to potato leafhopper; damage by pests were visually evaluated. Quality was visually evaluated based on vigor and uniformity within each population. Vigor and uniformity was assessed yearly in the nursery plantings and immediately before each grazing event in the grazing trial. The eight-week grazing trial allowed for two grazing events for each of the nine replications. Grazing tolerance and regrowth were measured weekly for each replication throughout the eight weeks of grazing. Accessions and cultivars showed a significant difference in 2013 and 2015 for potato leaf hopper damage (P <0.0001). There were also significant differences between accessions and cultivars for population uniformity and vigor scores and winter survival (P <0.0001). Winter survival ranged from 0 to 100% while uniformity scores of surviving plots ranged from 1 to 5. A positive correlation was seen between plant survival and uniformity and vigor scores both in 2014 and 2015. PI306182, S3149, PI262530, PI262529, and PI255305 were high in vigor and uniformity scores averaged across 2014 and 2015; 2013 scores were not significantly different. 'Pardee', 'Leo', 'Empire' and 'Bull' were highest in uniformity and vigor scores for commercial cultivars averaged across 2014 and 2015. Growth habit was measured as height/width ratio and significant differences were seen in 2013 and 2015 but not in 2014. Cluster analysis divided the 51 acce...