Publication Date

1997

Description

Results from a series of six comparative lamb grazing trials with temperate forages are summarised, and compared with results from the literature. Condensed tannin (CT) concentrations in the diet ranged from 0.12% to 0.47% on a dry matter (DM) basis. Values were generally similar for Yorkshire fog (Holcus lanatus), perennial ryegrass (Lolium perenne) and annual ryegrass (L. multiflorum), each grown with white clover (Trifolium repens), in similar circumstances. Concentrations for tall fescue (Festuca arundinacea)/white clover pastures were relatively low, but may have been artefacts. Drenching with polyethylene glycol (PEG) to bind dietary CT generally reduced live weight gain, wool growth and carcase weight, though effects were only significant at CT concentrations. Use of PEG enhanced wool production in lambs grazing perennial ryegrass. It is suggested that a CT concentration of 0.5% in the DM represents the marginal value above which consistent advantages to animal performance might be expected, and that this concentration may be achieved in temperate grasses by appropriate plant selection techniques.

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Influence of Low-Level Condensed Tannins Concentrations in Temperate Forages on Sheep Performace

Results from a series of six comparative lamb grazing trials with temperate forages are summarised, and compared with results from the literature. Condensed tannin (CT) concentrations in the diet ranged from 0.12% to 0.47% on a dry matter (DM) basis. Values were generally similar for Yorkshire fog (Holcus lanatus), perennial ryegrass (Lolium perenne) and annual ryegrass (L. multiflorum), each grown with white clover (Trifolium repens), in similar circumstances. Concentrations for tall fescue (Festuca arundinacea)/white clover pastures were relatively low, but may have been artefacts. Drenching with polyethylene glycol (PEG) to bind dietary CT generally reduced live weight gain, wool growth and carcase weight, though effects were only significant at CT concentrations. Use of PEG enhanced wool production in lambs grazing perennial ryegrass. It is suggested that a CT concentration of 0.5% in the DM represents the marginal value above which consistent advantages to animal performance might be expected, and that this concentration may be achieved in temperate grasses by appropriate plant selection techniques.