JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. British Ecological Society is collaborating with JSTOR to digitize, preserve and extend access to Journal of Applied Ecology. Summary 1. With changes in the agricultural policy for rural areas in the UK there is increased interest in the development of management protocols for indigenous and sown swards in upland Scotland based on grazing by ruminant species other than sheep and cattle, e.g. goats, red deer and South American camelids. 2. Here we describe the diet composition over two seasons of goats, red deer and South American camelids (guanacos) grazing three vegetation types typical of upland ecosystems in the UK: a sown sward (Lolium perenne-dominated), an indigenous grassland (Nardus stricta-dominated) and a dwarf shrub community (Calluna vulgarisdominated). 3. On each vegetation type, all three animal species were selective feeders. The composition of the goats' diet was more variable than that of the red deer and guanacos. All three species were more selective when grazing the indigenous communities than when grazing the sown sward. 4. On the Lolium sward, the guanacos avoided clover and other dicotyledonous plants, whilst the goats and red deer consumed green leaf from all plant categories found at or near the sward surface. 5. On the Nardus community, all three species avoided the dominant tussock-grass and selected green lamina of broad-leaved grasses from the species-rich inter-tussock areas. Between-species differences in minor components included an increased contribution of non-grass monocotyledonous plants to the goats' diet in spring, and a higher proportion of grass flowerstem and grass seed/flowerhead in the guanacos' diet in summer. 6. The diets of the three species of animal on the Calluna community were broadly similar. All generally avoided C. vulgaris and strongly selected graminoid species. Consumption of grass was greater in spring than summer. 7. Species differences in diet composition, particularly on indigenous swards dominated by N. stricta and C. vulgaris, might facilitate vegetation management and improve animal output using multispecies grazing systems.

No abstract

Mixed-grazing systems occur when two or more large herbivores graze together. Body size and anatomical differences between animal species are reflected in differences in their selected diet and foraging behaviour, which can bring about opportunities for complementary pasture use. The extent to which niche separation occurs within farming systems depends on the degree of sward heterogeneity and the scale of the resource available, with cultivated swards generally offering comparatively little occasion for selective grazing, in comparison to native pastures. However, even then there are opportunities for mixed grazing to benefit productivity. A range of studies have shown that if sheep are grazed together with cattle on simple grass/white clover swards, the performance of the sheep is improved in comparison to sheep-only grazing, leading to a higher total output per unit area. Semi-natural vegetation communities offer much more opportunity for selective grazing as they are generally more botanically and structurally diverse. Examples are given of the impact of losing large and small grazers from grazed ecosystems in marginal areas. Loss of cattle grazing from the uplands of Wales has been instrumental in the spread of invasive hill grass species linked to the loss of heathland habitats of international conservation importance. Conversely, the loss of sheep and goats from common lands in the Cantabrian Mountains has led to the progressive expansion of woody vegetation, again at the expense of heathlands. Such examples highlight the role that mixed grazing can play in promoting economic and environmental sustainability, particularly in marginal areas.

No abstract

The production and utilization of complementary cereal/legume bi-crops as ruminant feeds is beneficial for several reasons. The nitrogen fixation by the legume reduces the amount of fertilizer nitrogen required by the cereal. The cereal in turn supports the legume, thereby preventing the lodging that typifies pure stands of mature forage peas. When bi-crops are fed, the legume and cereal components respectively provide relatively low cost protein and energy, which may be synchronously supplied to the animal. In Denmark, pea-barley bi-crops are reported to reduce the cost of feeding without reducing intake and animal performance (Kristensen, 1992). However, little is known about the intake potential and level of animal performance sustainable from such bi-crops when produced and fed under UK conditions. Therefore this study determined the intake, in vivo digestibility and nitrogen (N) balance in sheep of spring sown, peawheat bi-crop silages harvested at three stages of maturity.