Original scientific paper
INFLUENCE OF FEEDING LEVEL ON EFFECTIVE RUMEN DEGRADABILITY OF ALFALFA HAY AND MAIZE SILAGE
M. Pourabedin
; Department of Animal Science, Abouraihan Campus, University of Tehan, Tehran, Iran
A. Afzalzadeh
; Department of Animal Science, Abouraihan Campus, University of Tehan, Tehran, Iran
A. A. Khadem
; Department of Animal Science, Abouraihan Campus, University of Tehan, Tehran, Iran
Abstract
The objective of this study was to evaluate the effect of feeding level (FL) on effective rumen degradability (ED) and In situ disappearance kinetics of dry matter and neutral detergent fiber (NDF) of alfalfa hay and maize silage. Standard procedure for nylon bags technique was used to estimate ruminal disappearance of dry matter (DM) and NDF. Nylon bags containing samples were incubated for 8, 16, 24, 48, 72 and 96 h in the rumen of four ruminally cannulated sheep (wether) and the exponential model of Ørskov and McDonald (1979) was used to calculate degradation kinetics. The ruminal degradability of forages samples were measured at four levels of intake. In maize silage, ED of DM decreased from 56.9% to 40.7% as intake increased from 1 to 2.5 times of maintenance. Values for the ED of dry matter of alfalfa hay at FL 1, 1.5, 2 and 2.5 averaged 60.3, 55.3, 44.5 and 42.9% respectively. In general, ED was significantly (p<0.01) higher at the maintenance level of feeding (FL=1) than for other treatments. The same situation was seen in NDF degradation of both forages. ED of NDF decreased from 53.08% at FL 1 to 39.78% at FL 2.5 in alfalfa hay and from 42.58% to 32.18% in maize silage. The results of this experiment indicated that ED of DM and NDF decreased dramatically when FL increased to more than 2 times of maintenance energy
Keywords
feeding level; effective degradability; disappearance kinetics
Hrčak ID:
50651
URI
Publication date:
25.9.2009.
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