Cilj ovog rada bio je ocijeniti djelovanje razine hranidbe (RH) na djelotvornu razgradljivost (DR) u buragu i nestanak in situ kinetike suhe tvari (ST) i neutralna deterdženta vlakna (NDV) sijena lucerne i kukuruzne silaže. Primijenjen je standardni postupak najlonskih vreća za procjenu nestanka suhe tvari i neutralna deterdženta vlakna. Najlonske vreće s uzorcima inkubirane su na 8,16, 24, 48, 72 i 96 sati kanilama u burag četiriju ovaca (wether), a primijenjen je eksponencijalni model Orskova i McDonalda (1979) za izračunavanje kinetike degradacije. Mjerena je razgradljivost u buragu uzoraka krmiva na četiri razine unosa. U kukuruznoj silaži smanjili su se djelotvorna razgradljivost suhe tvari od 56.9% na 40.7% s povećanjem unosa od 1 do 2.5 puta većeg od uzdržnih potreba. Vrijednosti za DR suhe tvari sijena lucerne na razini hranidbe 1, 1.5, 2 i 2.5 u prosjeku su bile 60.3, 55.3, 44.5 i 42.9%. Općenito, DR je bila značajno viša (p>0.01) za RH=1 nego za druge postupke. Isto je primijećeno u NDV degradaciji oba krmiva. Djelotvorna razgradljivost NDV-a smanjila se od 53.08% uz RH 1 do 39.78% uz RH 2.5 u sijenu lucerne i od 42.58% na 32.18% u kukuruznoj silaži. Rezultati ovog istraživanja pokazuju da se DR suhe tvari i NDF dramatično snizuje kad RH raste više od 2 puta od potreba za uzdržnu energiju.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 energ
