Abstract :
Wooded rangelands are a vast grazing land resource globally, including shrublands, savannas and forested ranges. They
generally provide forage year-round for small ruminants and they are vitally important for livestock production, especially goats.
While the productivity ofwooded rangelands is lowto moderate, their importance to small ruminant production is considerable. In
this paper,we begin by discussing some anti-quality characteristics (mechanical and chemical defences) ofwoody vegetation that
reduce their forage value, deter foraging, and reduce performance and productivity of small ruminants.We then present examples
of grazing studies that illustrate how small ruminants select their diets on wooded rangelands. We conclude by discussing why
small ruminants select the diets they do within the evolutionary processes of plant–herbivore interactions. Finally, we discuss
how this knowledge can be integrated into approaches for sustainable management of wooded rangelands for small ruminant
production. Plant defences are abundant in wooded rangelands but they are not a complete barrier to small ruminants as they often
use woody plants as part of their diets. Indeed plants with such defences may represent a significant forage resource enabling
small ruminants to survive on wooded rangelands with a prolonged dry period when more preferred defenceless species are
absent. Future research in plant–herbivore interactions should include investigating how plant biochemical diversity influences
herbivore preference for various plant communities, and integrating this information to develop recommendations for managing
wooded rangelands.
© 2005 Elsevier B.V. All rights reserved
Keywords :
Diet selection , Physical and chemical plant defences , Anti-quality , Grazing behaviour