Opportunities for telemetry techniques in studies on the nutritional ecology of free-ranging domesticated ruminants

Abstract

<jats:p>The principles of domestic herbivore nutrition are well understood and have been developed through detailed physiological studies, although methods to accurately measure field-based intake still challenge herbivore nutrition research. Nutritional ecology considers an animal's interaction with the environment based on its nutritional demands. Although there are a number of theoretical frameworks that can be used to explore nutritional ecology, optimal foraging provides a suitable starting point. Optimal foraging models have progressed from deterministic techniques to spatially explicit agent-based simulation methods. The development of optimal foraging modelling points towards opportunities for field-based research to explore behavioural preferences within studies that have an array of nutritional choices that vary both spatially and temporally. A number of techniques including weighing animals, weighing herbage, using markers (both natural and artificial) and sampling forage, using oesophageal-fistulated animals, have been used to determine intake in the field. These intake measurement techniques are generally most suited to studies that occur over a few days and with relatively small (often less than 10) groups of animals. Over the last 10 years, there have been a number of advances in automated behavioural monitoring technology (e.g. global positioning systems) to track animal movement. A number of recent studies have integrated detailed spatial assessments of vegetation using on-ground sampling and satellite remote sensing; these data have been linked to behavioural preferences of herbivores. Although the recent studies still do not address nutritional interactions over months or years, they do point to methods that could be used to address landscape scale nutritional interactions. Emerging telemetry techniques used to monitor herbivore behavioural preferences and also to determine detailed landscape vegetation mapping provide the opportunity for future herbivore nutritional ecology studies.</jats:p>

How to estimate variability in affinity relationships in partially observed groups of domestic herbivores?

“…Continued research at both theoretical and applied levels is thus needed (Bailey et al, 1998;Boval and Dixon, 2012;Swain and Friend, 2013). limitation of agonistic interactions) in intensive production systems and for grassland use in the more extensive systems.…”

Utilization of Biomarkers to Study the Grazing Behavior of Herbivore Species

“…This spectrum gives a specific signature depending on the presence, character and number of important chemical bonds, such as OH, NH and CH [28]. According to Swain and Friend [29], one of the major limitations pointed out to NIRS applications (i.e. estimation of feed intake, digestibility and diet composition) is the need to have accurate calibration equations based on known and estimated nutritional parameters that will obviously vary for each specific situation (vegetation community).…”

“…Early studies used visual field observations to assess these temporal and spatial modifications of rangeland use by both domestic and wild herbivores [30]. The utilization of recent available telemetry techniques can help grazing scientists to assess landscape vegetation preferences of herbivores [29], increasing the number of observed animals and reducing significantly the labour and allowing the collection of high-quality and unbiased data over a 24-h period. Identification of the preferred grazing sites can be accomplished by using telemetry devices, as global positioning systems (GPS).…”

“…This information together with data on the spatial arrangement of the plant communities can be used to assess the animals' patch selection. According to Swain and Friend [29], the spatial arrangement of vegetation (number and size of the patches) will determine the level of local accuracy needed, i.e. small patches in larger number will need a higher accuracy of location data.…”

Editorial: Eighth International Symposium on the Nutrition of Herbivores (ISNH8) in Aberystwyth, Wales, in 2011

“…Swain and Friend (2013) discussed how the developments in spatial assessments of available vegetation using on-ground sampling and satellite remote sensing are creating new opportunities to increase the understanding of the nutritional ecology of herbivores. Friggens et al (2013) reviewed the major advances in predicting nutrient partitioning in the dairy cow, with emphasis on cow genotype and animal response when nutrient supply is limited or more variable.…”