A sejtfal lebontas mertekenek es sebessegenek osszefuggese a taplaloertekkel, valamint a takarmanyozasi szinttel kerodzoknel.
1996
Varhegyi J. | Rozsa L. | Hegerne J.Zs.
Rate of the degradation of cell wall (NDF=neutral detergent fibre) might have an effect on the quantity of potentially digestible NDF escaping ruminal fermentation as feeding level increases. Digestibility depression of organic matter (OM), NDF and the rate of ruminal degradation of NDF were studied in digestibility trials using the in sacco technique. Samples of maize silage (n=7), grass (n=8) and lucerne (n=11): fresh, ensiled and hay, were fed at different levels to wethers (n=191). NDF degradation of the same samples fed in digestibility trials was measured in sacco using cannulated cows, incubation lasted for 2, 4, 8, 16, 24, 48, 72 and 96 h. (n=133 x 8). Rate of degradation was calculated according to both Orskov-McDonald and L-T models. As dry matter intake (expressed as of liveweight) increased by 1 unit, OM and NDF digestibility decreased by 3,7 and 6,7, 6,0 and 8,6, 6,3 and 12,5 units for lucerne, grass and maize, respectively. Rate of NDF degradation of the same feeds was 6, 1, 4, 6 and 3,8/h. The extent of digestibility depression of OM was positively related to NDF content, the potential extent of NDF digestion, and the digestibility depression of NDF (r=0,83, P<0,001). It was negatively related to ADL (acid detergent lignin content and rate of NDF degradation (r=-0,83, P<0,001). The extent of digestibility depression is different for different feeds. The digestibility depression, due to increased feeding level, is higher for feeds having high amounts, highly digestible and slowly degradable cell walls.
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