Condensed Tannins in the Gastrointestinal Tract of Cattle after Sainfoin (Onobrychis viciifolia) Intake and Their Possible Relationship with Anthelmintic Effects

Abstract

Condensed tannins' (CTs) fate along the digestive tract of ruminants may account for the variable efficacy of CTs against gastrointestinal nematodes. We analyzed CTs in the digesta of cattle fed sainfoin. With the acetone-butanol-HCl assay, the total CTs concentrations in the digesta were close to those in the diets (6.3 and 1.5% of DM in experiments 1 and 2, respectively); thus, CTs remained potentially largely undegraded/unabsorbed. With the thiolysis assay, CTs concentration was much higher in the abomasum (2.3% of DM; expt 1) compared with the rumen and intestines, along with higher mean size and prodelphinidins percentage, corroborating CTs efficacy reported only against Ostertagia ostertagi in the abomasum. In expt 2, the dietary levels of CTs were probably too low to demonstrate anthelmintic effects in the rumen. Overall, the level of CTs accessible to thiolysis is favored under the acidic conditions of the abomasum, which seems critical for anthelmintic activity.

Benefits of Condensed Tannins in Forage Legumes Fed to Ruminants: Importance of Structure, Concentration, and Diet Composition

“…According to results from the HCl-butanol-acetone or thiolysis assays, fermentation can reduce "apparent" CT concentrations by 30 or 85%, respectively, in silages (Mena et al, 2015;Ramsay et al, 2015) and the gut (Desrues et al, 2017;Quijada et al, 2018). According to results from the HCl-butanol-acetone or thiolysis assays, fermentation can reduce "apparent" CT concentrations by 30 or 85%, respectively, in silages (Mena et al, 2015;Ramsay et al, 2015) and the gut (Desrues et al, 2017;Quijada et al, 2018).…”

“…(Gea et al, 2011;Pérez-Jiménez and Lluís Torres 2011;Cheynier et al, 2015;Hixson et al, 2016;our unpublished data). Low values have been linked to oxidative processes affecting reaction yields (Hixson et al, 2015;Klongsiriwet, 2016;Brillouet et al, 2017;Desrues et al, 2017). Thiolysis or phloroglucinolysis (analytical degradation of CTs with thiols or phloroglucinol) can be used to determine the composition of CTs by depolymerization, enabling characterization of the flavan-3-ol subunits (Zeller, 2019).…”

“…However, despite these apparent losses, sericea lespedeza and sainfoin silage extracts and silages still exerted anthelmintic effects in vitro by inhibiting the exsheathment of H. contortus L3 larvae and in vivo by lowering adult worm burden and fecal egg counts (Heckendorn et al, 2006;Manolaraki, 2011;Terrill et al, 2016). A high activity against O. ostertagi nematodes of the abomasum contrasted with no activity against intestinal Cooperia oncophora nematodes and was associated with 2.3% CTs (g 100 g −1 dry matter by thiolysis) in the abomasum vs. 0.02% CTs in the intestine (Desrues et al, , 2016b(Desrues et al, , 2017. A high activity against O. ostertagi nematodes of the abomasum contrasted with no activity against intestinal Cooperia oncophora nematodes and was associated with 2.3% CTs (g 100 g −1 dry matter by thiolysis) in the abomasum vs. 0.02% CTs in the intestine (Desrues et al, , 2016b(Desrues et al, , 2017.…”

“…However, quantification remains problematic, and higher CT yields have been reported in some samples with the HCl-butanol-acetone assay than with the thiolysis or phloroglucinolysis assays. Low values have been linked to oxidative processes affecting reaction yields (Hixson et al, 2015;Klongsiriwet, 2016;Brillouet et al, 2017;Desrues et al, 2017).…”

“…Work has started on determining how fermentation affects CT concentrations and bioactivities. According to results from the HCl-butanol-acetone or thiolysis assays, fermentation can reduce "apparent" CT concentrations by 30 or 85%, respectively, in silages (Mena et al, 2015;Ramsay et al, 2015) and the gut (Desrues et al, 2017;Quijada et al, 2018). However, despite these apparent losses, sericea lespedeza and sainfoin silage extracts and silages still exerted anthelmintic effects in vitro by inhibiting the exsheathment of H. contortus L3 larvae and in vivo by lowering adult worm burden and fecal egg counts (Heckendorn et al, 2006;Manolaraki, 2011;Terrill et al, 2016).…”