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Twelve lactating Friesian Cows with body weight of 450 to 550 kg and in the second to fifth lactating season were used after 8 weeks of cal-ving in a complete switch-back design. The cows were fed a basal ration of 35% concentrate feed mix-ture with 40% berseem and 25% rice straw(on a dry matter(DM)basis)without supplementation(G)or supplemented with 5 and 10 g zinc methionine per head per day(G and G, respectively). Nutrient di-gestibility coefficients and nutritive values were signif-icantly increased(P < 0.05)by zinc methionine sup-plementation. Cows in G had the highest feed intake of total digestible nutrients(TDN)and digestible crude protein(DCP), followed by G and G, re-spectively(P