[Eight Massese ewes were fed 4 diets based on lucerne hay: control (C), with protected soaps (L), with protected methionine (M), with protected soaps and methionine (LM), in a Latin square 4 x 4 experimental design. During experimental periods, each lasting one week, ewes were milked twice daily (8.00 a.m. and 07.00 p.m.). Feed intake and milk production were recorded. Furthermore, quality, rheological traits and acid content of milk fat, as well as diet digestibility, were determined. The preliminary results show that LM diet raised milk fat by about one point (P0.01). All other parameters measured so far were not affected]