EN
The digestibility of Italian rye-grass /Lotos, Kroto, Telga and GOH varieties/ and three mixtures of Meadow fescue with red clover /75:25, 50:50, 25:75/ was evaluated by two in vitro techniques - standard method of Tilley and Terry or by modified method in which samples were incubated in the nylon bags and washed out in the washing-machine. It was found out that in vitro digestibility coefficients of forages were significantly correlated with the in vivo results /P ≤ 0,01/. Digestibility of organic dry matter obtained by the modified in vitro method appeared to be better correlated with in vivo data as compared to the standard in vitro technique. Both in vitro methods, standard and modified, appeared to be less suitable for estimation of the crude protein dogestlbillty in the green forages.