Three experiments were conducted to evaluate the effect of corn hybrid and stage of maturity on physical and chemical characteristic of corn silage and dairy cattle performance. In experiment 1 and 2, S.C.604, T.W.C.647 and S.C.704 were grown in randomized block design plot with 4 replicates for laboratory evaluation. In experiment 1, Whole Plant samples of hybrids harvested at six maturity stages (silking, blister, milk, dough, early dent and late dent) and separated into ear (grain and cob), leaf, stem, tassel and husk. Type of hybrid significantly affected plant height, NDF, ADF and OM content of stover, stem-stover and whole plant ratio, stem diameter, leaf no., husk-stover ratio, tassel weight, tassel-stover and whole plant ratio, cob dry weight, cob-whole plant ratio and number of ear kernel rows, also there was a significant effect of maturity on green and dry weight and DM percentage of whole plant, green and dry weight of stover, stover-whole plant ratio, dry matter, NDF, ADF, CP and OM content of stover, stem and leaf weight, stem-stover and whole plant ratio, stem diameter, leaf no., leaf-whole plant ratio, husk weight, husk-stover and whole plant ratio, tassel weight, tassel-stover and whole plant ratio, ear weight, length, diameter, and DM, ear-whole plant ratio, DM weight of cob, cob-ear and whole plant ratio, ear kernels DM weight, weight of 100 kernels, kernel-ear and whole plant ratio and kernel density but no effect of maturity was observed for plant height, leaf-stover ratio, ear no. and ear kernel rows. In experiment 2, Hybrids were harvested at four maturity stages (milk, dough, early dent and late dent) and ensiled in 36 laboratory silos. Silage pH, lactic acid and total acid concentration, dry matter, CP and NDF content differed between hybrids but there was no effect of hybrid on acetic acid, propionic acid and butyric acid concentration, organic matter and ADF content of experimental silages. pH, acetic acid, butyric acid, lactic acid and total acid concentration, dry matter, OM, CP, NDF and ADF content of silage was significantly affected by maturity. In third experiment two corn hybrids, S.C.704 and T.W.C.647 were used to evaluate the effects of hybrid and maturity on dairy cattle performance when corn was fed as silage in the diet of Holstein cows. Corn hybrid S.C.704 harvested at milk and late dent while harvesting times for hybrid T.W.C.647 were at dough and early dent maturity stages. Eight multiparous cows were used in a replicated experiment with a 4×4 Latin square design with 21-d periods. Milk, 3.5% FCM, fat yield, protein percentage and production did not differ among treatments, however, dry matter intake, silage and nutrients intake, milk fat, lactose and total solids concentrations, feed efficiency, nutrients digestibilities, feces pH and kernel co.