Nutritional Ecology of Grazing and Browsing Ruminants

Duncan, Alan J.; Poppi, D. P.

doi:10.1007/978-3-540-72422-3_4

Cited by 42 publications

(44 citation statements)

References 68 publications

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“…3 Comparison of the mean percentage of monocots in the faeces of impala on granitic and gabbroic soil over time. On the x-axis, the eight sample periods from the beginning of February (end of the wet summer period) until the end of May (mid dry winter period) are displayed: 1 means the first 2 weeks of the month and 2 the last 2 weeks although digestion of especially hindgut fermenters is assumed to be negatively affected under high concentrations of condensed tannins (Duncan and Poppi 2008). It has been suggested that elephant can tolerate condensed tannins (Lagendijk et al 2005;Wessels et al 2007).…”

Section: Month % Monocots In Faecesmentioning

confidence: 99%

“…On the other hand, grass generally has higher digestibility than browse (Van Wieren and Van Langevelde 2008), which is mainly due to the lower content of lignified fibre in grass (Hummel et al 2006). Browse contains more secondary compounds than grass, which reduce intake by herbivores (Jansen et al 2007;Duncan and Poppi 2008). For example, tannins are pervasive in browse but almost absent in grass (Ellis et al 1990).…”

Section: Introductionmentioning

confidence: 99%

“…As ruminants, they probably have long gut retention time and hence digestion efficiency is high (Hofmann 1989;Clauss et al 2003). Meeting these high nutrient requirements becomes more difficult when condensed tannins and forages with high concentrations of fibre are consumed because digestion in ruminants is assumed to be limited at high tannin concentration (Duncan and Poppi 2008). It has been suggested that small animals are less able to process high-fibre diets than large animals (Bell 1971;Jarman 1974;Clauss et al 2003), although other studies could not find evidence for this (Pérez-Barbería et al 2004;Clauss et al 2009).…”

Section: Introductionmentioning

confidence: 99%

“…Mopane can provide the bulk for elephants, particularly in the dry season. In contrast, impalas need relatively high-quality forage and are assumed to be more limited by high amounts of condensed tannins than elephant (Duncan and Poppi 2008). Finally, we tested whether impalas on nutrient-rich soils have a diet consisting of more grass and change later to a diet of more browse than impalas on nutrient-poor soils.…”

Section: Introductionmentioning

confidence: 99%

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Seasonal diet changes in elephant and impala in mopane woodland

et al. 2011

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Elephant and impala as intermediate feeders, having a mixed diet of grass and browse, respond to seasonal fluctuations of forage quality by changing their diet composition. We tested the hypotheses that (1) the decrease in forage quality is accompanied by a change in diet from more monocots in the wet season to more dicots in the dry season and that that change is more pronounced and faster in impala than in elephant; (2) mopane (Colophospermum mopane), the most abundant dicot species, is the most important species in the elephant diet in mopane woodland, whereas impala feed relatively less on mopane due to the high condensed tannin concentration; and (3) impala on nutrient-rich soils have a diet consisting of more grass and change later to diet of more browse than impala on nutrient-poor soils. The phosphorus content and in vitro digestibility of monocots decreased and the NDF content increased significantly towards the end of the wet season, whereas in dicots no significant trend could be detected. We argue that this decreasing monocot quality caused elephant and impala to consume more dicots in the dry season. Elephant changed their diet gradually over a 16-week period from 70% to 25% monocots, whereas impala changed diets rapidly (2-4 weeks) from 95% to 70% monocots. For both elephants and impala, there was a positive correlation between percentage of monocots and dicots in the diet and the in vitro digestibility of these forage items. Mopane was the most important dicot species in the elephant diet and its contribution to the diet increased significantly in the dry season, whereas impala selected other dicot species. On nutrient-rich gabbroic soils, impala ate significantly more monocots than impala from nutrient-poor granitic soils, which was related to the higher in vitro digestibility of the monocots on gabbroic soil. Digestibility of food items appears to be an important determinant of diet change from the wet to the dry season in impala and elephants.

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Section: Month % Monocots In Faecesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Seasonal diet changes in elephant and impala in mopane woodland

et al. 2011

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“…For browsers, such as white-tailed deer, their small rumen, and the rapid rate of materials moving through it, results in deer selectively consuming forbs with cells high in soluble fractions of carbohydrates (Fulbright andOrtega 2006, Garibaldi et al 2007) and cell walls rich in rapidly fermentable components, such as pectin (Hummel et al 2006). In contrast, grazers with large rumens use grass as a primary energy source, which requires a long period of rumen retention for microbial breakdown of hemicellulose and cellulose in cell walls to volatile fatty acids (Fulbright and Ortega 2006, Clauss et al 2008, Duncan and Poppi 2008. Bison are grazers (Damuth and Janis 2011) and can increase diversity and abundance of prairie forbs because they consume mostly grasses and, thereby, reduce competitiveness of grasses against forbs (Collins et al 1998, Knapp et al 1999.…”

mentioning

confidence: 99%