How do severity and frequency of grazing affect sward characteristics and the choices of sheep during the grazing season?

Grass and Forage Science - Tập 58 Số 2 - Trang 138-150 - 2003
Florence Garcia-Launay1,2, Pascal Carrère1, Jean‐François Soussana1, René Baumont2
1INRA – Unité d'Agronomie, Fonctionnement et Gestion de l'Ecosystème Prairial, Clermont-Ferrand, France
2INRA – Unité de Recherches sur les Herbivores, Relations Animal–Plantes, Site de Theix, St-Genès-Champanelle, France

Tóm tắt

AbstractThe effect of grazing frequency and severity on sward characteristics and preferences by sheep was investigated from April to September. Two levels of grazing severity were imposed by varying the numbers of ewes grazing 200 m2 plots for 24 h: four (S, severe) or two (L, lax) ewes. Grazing frequency was either 1 d week−1 (F, frequent) or 1 d every 2 weeks (I, infrequent). By combining frequency and severity, four treatments were obtained: SF, LF, SI and LI. The six binary combinations (SF/LF, SF/SI, SF/LI, LF/SI, LF/LI and SI/LI) were studied in preference tests.Treatments LF, SI and LI were characterized by a high sward surface height, biomass and amount of reproductive green tissues relative to treatment SF. Herbage quality was not different between the grazing treatments between April and July. In September, after a 6‐week period of regrowth, herbage quality was significantly higher for the SF treatment than the other treatments.The sheep preferred the swards grazed at a low frequency between April and July, and then changed their preference in favour of the sward with higher quality herbage (treatment SF). The relative abundance of green laminae and the relative digestibility of the swards helped to explain the preferences observed. For a low grazing pressure at the spatio‐temporal scale studied, sheep should graze swards at a relatively low frequency but at a high severity of grazing rather than the reverse.

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Tài liệu tham khảo

10.1007/s004420100737

Aufrère J., 1983, Feeding Value of By‐products and Their Use by Beef Cattle, 25

BirchamJ.S.(1981)Herbage growth and utilisation under continuous stocking management. Ph.D. thesis. University of Edinburgh Edinburgh.

Baumont R., 2002, Development of a spatial multi‐agent model of a herd of ruminants grazing an heterogeneous grassland, Rencontres Recherches Ruminants, 9, 69

Chapman D.F., 1993, Grasslands for Our World, 55

Cody R.P., 1997, Applied Statistics and the SAS Programming Language (4th edn), 189

10.1016/S0168-1591(00)00116-7

10.2307/4003033

Dagnelie P., 1992, Théorie et méthodes statistiques, Tome 2, 361

10.4141/P01-040

10.1016/0168-1591(95)00553-5

10.1016/0168-1591(95)00598-M

10.1016/S0168-1591(96)01095-7

10.2307/2265752

Garcia F., 2002, Multi‐Function Grasslands, Quality Forages, Animal Products and Landscapes. Proceedings of the 19th General Meeting of the European Grassland Federation, La Rochelle, France, 2002, 248

10.1017/S0021859602002769

Ginane C., 2002, Multi‐Function Grasslands, Quality Forages, Animal Products and Landscapes. Proceedings of the 19th General Meeting of the European Grassland Federation, La Rochelle, France, 2002, 248

Goering H.K., 1970, Agricultural Handbook No. 379, 1

10.1007/s004420000367

10.1016/S0304-3800(00)00426-9

10.1890/0012-9658(1999)080[1008:DSIGAT]2.0.CO;2

10.1111/j.1365-2494.1985.tb01776.x

10.1080/00288233.1984.10430413

10.1111/j.1365-2494.1988.tb02149.x

Laca E.A., 1991, Plant Chemical Defences Against Mammalian Herbivory, 29

10.2307/2390572

10.1111/j.1365-2494.1988.tb02137.x

10.1111/j.1365-2494.1988.tb02136.x

10.1111/j.1365-2494.1988.tb02140.x

10.1079/9780851994529.0289

10.1016/S0022-5193(05)80114-6

10.1016/S0168-1591(96)01139-2

10.1016/S0168-1591(97)00110-X

10.1093/beheco/6.2.209

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Grass and Forage Science

Tập 58 Số 2

138-150

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