im saisonalen Verlauf - Kora

4. Roe deer had a smaller selectivity factor (the quotient of particlereticulorumen retention time over fluid reticulorumen retention time)(SF = 1,55 ± 0,16) than mouflon (SF = 2,1 ± 0,29). This indicates thatroe deer reduce the food particle size more efficiently during initialingestion than mouflon, and that the forestomach particle retention isless selective in roe deer because of a less prominent (or absent)ingesta stratification.5. The fluid volume of the reticulorumen of roe deer was smaller thanthat of mouflon.6. The content of indigestible material in the gastro-intestinal-tract andthe daily faecal volume increased for both roe deer and mouflonduring late summer and autumn and were constant during the rest ofthe year.7. The concentrations of short-chain fatty acids varied according to bothtime of day and season, depending on food intake and composition.The molar proportions typical for concentrate selectors and grassand roughage eaters could be demonstrated for both species.Roe deer are, in contrast to mouflon, more limited in their capacity to digestcellulose-containing plants due to the short particle retention times in thereticulorumen. Because the ingesta is retained only shortly in roe deer in springand summer, there is not sufficient time for cellulose fermentation, even thoughcellulolytic enzymes are available in sufficient amounts. On the other hand,cellulose fermentation is limited in winter by the scarcity of cellulolytic enzymes inspite of a prolonged ingesta retention. Longer particle retention time in thereticulorumen of mouflon provides favourable conditions for cellulose fermentationin all seasons. The seasonally variable ingesta retention times in the gastrointestinal-tractare an expression of the adaptation capacities of both species tothe seasonally fluctuating food supply.97