Publication Date
1993
Description
All grazed swards exhibit heterogeneity in the spatial (horizontal and vertical) dispersion of species/biomass. A herbivore foraging at random within such a heterogeneous environment would ingest less nutrients than wou Id one which exploited the heterogeneity on offer through selective grazing. The suite of decision-making processes involved in the selective grazing we observe is termed the animal's foraging strategy. On first observation, intensively managed sown swards appear to offer little opportunity for a herbivore to exhibit a foraging strategy; however, opporlunities do exist and there is empirical evidence that herbivores foraging on sown swards tend to have a diet higher in digestibility than that on offer. This review· discusses some of the mechanisms whereby the herbivore might exploit this heterogeneity. The role of intake rate (both short and long term), bite selection and patch selection are discussed in relation to their contribution to the overall nutrient intake rate of the animal. Simple sown swards offer some ways of testing hypotheses concerning the mechanisms of foraging strategy in large mammalian herbivores. However, even in two component grass- legume swards there are complex plant-animal relationships which make an empirical approach to understanding foraging strategy time consuming. Modelling provides an opportunity to examine these complex relationships.
Citation
Gordon, I J. and Lascano, C, "Foraging Strategies of Ruminant Livestock on Intensively Managed Grasslands: Potential and Constraints" (2024). IGC Proceedings (1993-2023). 27.
https://uknowledge.uky.edu/igc/1993/session18/27
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Foraging Strategies of Ruminant Livestock on Intensively Managed Grasslands: Potential and Constraints
All grazed swards exhibit heterogeneity in the spatial (horizontal and vertical) dispersion of species/biomass. A herbivore foraging at random within such a heterogeneous environment would ingest less nutrients than wou Id one which exploited the heterogeneity on offer through selective grazing. The suite of decision-making processes involved in the selective grazing we observe is termed the animal's foraging strategy. On first observation, intensively managed sown swards appear to offer little opportunity for a herbivore to exhibit a foraging strategy; however, opporlunities do exist and there is empirical evidence that herbivores foraging on sown swards tend to have a diet higher in digestibility than that on offer. This review· discusses some of the mechanisms whereby the herbivore might exploit this heterogeneity. The role of intake rate (both short and long term), bite selection and patch selection are discussed in relation to their contribution to the overall nutrient intake rate of the animal. Simple sown swards offer some ways of testing hypotheses concerning the mechanisms of foraging strategy in large mammalian herbivores. However, even in two component grass- legume swards there are complex plant-animal relationships which make an empirical approach to understanding foraging strategy time consuming. Modelling provides an opportunity to examine these complex relationships.
