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The role of condensed tannins in the nutritional value of Lotus pedunculatus for sheep

* 3. Rates of body and wool growth

Published online by Cambridge University Press:  09 March 2007

T. N. Barry
T. N. Barry
Affiliation:
Invermay Agricultural Research Centre, Private Bag, Mosgiel, New Zealand
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Abstract

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1. Lotus pedunculatus (cv. Grasslands Maku) grown on acid low-fertility soil and containing high concentrations of condensed tannin (76–90 g/kg dry matter (DM)) was grazed by growing sheep for 31–42 d periods in three experiments. In Expt 2 an additional group of lambs grazed areas oversown with white clover (Trifolium repens) and red clover (Trifolium pratense). Lambs were transferred from grazing ryegrass (Lolium perenne) – white clover straight on to lotus in all experiments (unconditioned sheep). In Expt 3 a second group was included which had grazed high-tannin lotus for a pre-experimental period of 8 weeks (conditioned sheep).

2. Effects of condensed tannin on body and wool growth were assessed by studying responses to daily oral administration of polyethylene glycol (PEG; molecular weight 3350, 75–100 g/d). PEG forms a complex with condensed tannin, which is assumed to be inert in its passage through the digestive system, and so effectively reduces the nutritional effects attributable to high condensed-tannin concentrations.

3. Live-weight gain (LWG) in the absence of PEG was low (27–125 g/d) for sheep grazing high-tannin lotus, and PEG administration increased LWG by 41–61 g/d and increased wool growth. In Expt 3, responses to PEG supplementation tended to be less with conditioned than with unconditioned sheep, indicating that conditioned sheep had partially adapted to the high-tannin diet.

4. PEG supplementation had no effect on either LWG or wool growth of sheep grazing areas oversown with mixed clovers, confirming its effects as specific to forages containing condensed tannins. These experiments therefore conclusively show that high concentrations of condensed tannin induced by growing Lotus pedunculatus under low soil fertility conditions prevent maximum expression of LWG and wool growth in grazing sheep. These results contrast with high LWG (153–315 g/d) observed in growing sheep grazing the same lotus cultivar grown in high fertility soil and containing 20 g condensed tannin/kg DM, a level considered to be nutritionally beneficial.

Type
Papers on General Nutrition
Information
British Journal of Nutrition , Volume 54 , Issue 1 , July 1985 , pp. 211 - 217
Copyright
Copyright © The Nutrition Society 1985

References

Barry, T. N. (1984). Canadian Journal of Animal Science 64, Suppl., 181–182.CrossRefGoogle Scholar
Barry, T. N. & Duncan, S. J. (1984). British Journal of Nutrition 51, 485–491.CrossRefGoogle Scholar
Barry, T. N. & Forss, D. A. (1983). Journal of the Science of Food and Agriculture 34, 1047–1056.CrossRefGoogle Scholar
Barry, T. N. & Manley, T. R. (1984). British Journal of Nutrition 51, 493–504.CrossRefGoogle Scholar
Barry, T. N. & Reid, C. S. W. (1985). In Forage Legumes for Energy-Efficient Animal Production [Barnes, R. F., Minson, D. J. and Brougham, R. W., editors]. (In the Press.)Google Scholar
Gartner, R. J. W., Murphy, G. M. & Hoey, W. A. (1982). Journal of Agricultural Science, Cambridge 98, 23–29.CrossRefGoogle Scholar
John, A. & Lancashire, J. A. (1981). Proceedings of the New Zealand Grassland Association 42, 152–159.CrossRefGoogle Scholar
Kempton, T. J. (1979). In Physiological & Environmental Limitations to Wool Growth, pp. 209–222 [Black, J. L. and Reis, P. J., editors]. Armidale, Australia: University of New England Publishing Unit.Google Scholar
Lowther, W. L. & Barry, T. N. (1985). Proceedings of the New Zealand Society of Animal Production 45 (In the Press.)Google Scholar
McLeod, N. M. (1974). Nutrition Abstracts & Reviews 44, 803–815.Google Scholar
Trenkle, A. H. (1980). In Digestive Physiology and Metabolism in Ruminants, pp. 505–522. [Ruckebusch, Y. and Thivend, P., editors]. Lancaster: MTP Press.CrossRefGoogle Scholar
Ulyatt, M. J. & Egan, A. R. (1979). Journal of Agricultural Science, Cambridge 92, 605–616.CrossRefGoogle Scholar
Van Hoven, W. (1984). Canadian Journal of Animal Science 64, Suppl.177–178.CrossRefGoogle Scholar
Wallace, A. L. C. (1979). In Physiological and Environmental Limitations to Wool Growth, pp. 257–268 [Black, J. L. and Reis, P. J., editors]. Armidale, Australia: University of New England Publishing Unit.Google Scholar