bioavailability of three rumen protected methionine (met) sources with different protection methods (mepron® m85, evonik industries, germany; methioplus®, soda nutrition, italy and methilock®, tehrandaneh co. iran) were evaluated in 2 experiments with 6 canulated non-lactating holstein cows. in experiment 1, the ruminal in situ and mobile bag techniques were used for assessing ruminal degradabi...