title: Preference for tannin-containing supplements by sheep consuming endophyte-infected tall fescue hay.
abstract: Tannins may bind to alkaloids in endophyte-infected (E+) tall fescue and attenuate fescue toxicosis. To test this hypothesis, thirty-two 4-mo-old lambs were randomly assigned to 4 treatments (8 lambs/treatment) in a 2 by 2 factorial design that included a basal diet of tall fescue hay [E+ or endophyte-free (E-)] supplemented with (TS) or without (CS) bioactive Quebracho tannins. The concentration of ergovaline in E+ fed in 2 successive phases was 65 ± 21 µg/kg (Phase 1) and 128 ± 4 µg/kg (Phase 2). After exposure to hays and supplements, all lambs were offered choices between TS and CS and between E+ and E- hays. During Phase 1, lambs offered E+ consumed more hay than lambs offered E- (P = 0.03). Lambs on E+/TS displayed the greatest intake of hay and the least intake of TS (P < 0.05). During Phase 2, when the concentration of ergovaline increased, lambs offered E+ consumed less hay than lambs fed E- (P < 0.0001). Lambs on E+/CS consumed less hay than lambs on E-/CS (P = 0.02), but hay intake by lambs on E-/TS and E+/TS did not differ (P = 0.96). Lambs preferred CS to TS during preference tests (P < 0.0001) and lambs on E+/TS ingested the least amounts of supplement TS and the greatest amounts of supplement CS (P = 0.001). Lambs offered E+ displayed greater body temperatures than lambs offered E- in both phases (P < 0.05). When offered a choice among the 3 hays, lambs previously exposed to E+ preferred E+ (low content of ergovaline) > E- > E+ (greater content of ergovaline; P < 0.001). Thus, decreased concentrations of ergovaline increased rectal temperatures, and affected intake of and preference for tannins and fescue hay. Quebracho tannins did not attenuate the effects of E+ on body temperature and feed intake. Ingestion of E+ reduced intake of quebracho tannins, suggesting that alkaloids in E+ antagonized ingestion of condensed tannins.
authors: INRA, Unité d'Expérimentation 1354 sur les Ruminants de Theix, Theix, F-63122 Saint-Genès-Champanelle, France.
authors: M
authors: M
authors: Bernard
authors: B
authors: B
authors: Maughan
authors: J J
authors: JJ
authors: Villalba
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D030009:Aspidosperma / Q000737:chemistry; D001831:Body Temperature / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements / Q000032:analysis; D060026:Endophytes / Q000737:chemistry; D004879:Ergotamines / Q000008:administration & dosage / Q000633:toxicity*; D005260:Female; D031751:Festuca / Q000737:chemistry; D005518:Food Preferences / Q000187:drug effects*; D008297:Male; D034561:Sheep, Domestic / Q000502:physiology*; D013634:Tannins / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: D004879:Ergotamines; D013634:Tannins; C076760:ergovaline