No distinct difference in the excretion of large particles of varying size in a wild ruminant, the banteng (Bos javanicus)
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The forestomach of ruminants and camelids does not only allow a differential excretion of fluids and small particles but also a differential excretion of small and large particles. The question whether larger particles of different size classes are also retained for different time periods, or whether simply a particle-size threshold exists above which all particles of a size higher than this threshold are retained in an undifferentiated manner, has not been addressed so far. We determined the mean retention time (MRT) of different-sized large particles (10 and 20 mm) in three banteng (Bos javanicus) on two forage only diets, grass and grass hay. We used cerium-mordanted fibre (10 mm) and lanthanum-mordanted fibre (20 mm) as particle markers, mixed in the food. Average total tract MRT for large and very large particles at the grass diet was 58 and 56 h and at the grass hay diet 66 and 64 h, respectively. Very large particles moved slightly faster than large particles through the gut of the banteng. Three interpretations are possible: Very large particles are resubmitted to rumination sooner than large particles; ingestive mastication of the particle markers could have reduced the difference in the size of the particle markers; alternatively, particle retention may be governed by a threshold, above which all particles of a size higher than this threshold are retained in an undifferentiated manner. In order to test these possibilities, experiments with fistulated animals would have to be performed.
KeywordsRuminant Particle size Retention Ingestion Mastication
This study was supported by grants from the Freie Universität Berlin (NaFöG) to AS and the German Science Foundation (DFG) to SO (OR 86/1-1). We thank the staff of the Zoological Garden of Berlin, the IZW Berlin and the Landeslabor Brandenburg for their engaged support. This study complied with current German laws.
- Clauss M, Hummel J, Streich WJ (2006) The dissociation of the fluid and particle phase in the forestomach as a physiological characteristic of large grazing ruminants: an evaluation of available, comparable ruminant passage data. Eur J Wildl Res 52:88–98. doi: 10.1007/s10344-005-0024-0 CrossRefGoogle Scholar
- Faichney GJ (2006) Digesta flow. In: Dijkstra J, Forbes JM, France J (eds) Quantitative aspects of ruminant digestion and metabolism. CAB International, Wellingford, pp 49–86Google Scholar
- Lechner-Doll M, Rutagwenda T, Schwartz HJ, Schultka W, von Engelhardt W (1990) Seasonal changes of ingesta mean retention time and forestomach fluid volume in indigenous camels, cattle, sheep and goats grazing in a thornbush savanna pasture in Kenya. J Agric Sci 115:409–420. doi: 10.1017/S0021859600075869 CrossRefGoogle Scholar
- Lechner-Doll M, Kaske M, Engelhardt Wv (1991) Factors affecting the mean retention time of particles in the forestomach of ruminants and camelids. In: Tsuda T, Sasaki Y, Kawashima R (eds) Physiological aspects of digestion and metabolism in ruminants. Academic, San Diego, pp 455–482Google Scholar
- Schwarm A, Ortmann S, Wolf C, Streich WJ, Clauss M (2008) Excretion patterns of fluids and particle passage markers of different size in banteng (Bos javanicus) and pygmy hippopotamus (Hexaprotodon liberiensis): two functionally different foregut fermenters. Comp Biochem Physiol 150:32–39. doi: 10.1016/j.cbpa.2008.02.022 CrossRefGoogle Scholar