Abstract
Eight lactating Holstein cows were used in a 4×4Latin-square design to compare the feeding values of four experimental rations. Rations used were (A) grass silage, (B) grass silage plus 15kg corn silage, (C) grass silage plus 30kg corn silage and (D) corn silage. Timothy silage harvested at the heading stage (19.0% DM) was fed ad libitum in Rations A, B and C. Corn silage harvested at the yellow ripe stage (26, 8% DM) was fed at the rate of 0, 15, 30kg and ad libitum in Rations A, B, C and D, respectively. All the cows were fed 2kg of hay and 1kg of concen-trate per 5kg of milk produced daily. The principal results obtained were as follows: The total silage DM intake and the TDN intake increased with the increase in feeding levels of corn silage. The DCP intake was significantly lower (P<0.05) for Ration D than for other rations. The FCM production was significantly lower (P<0.05) for Ration A than for other rations. The percentage of solids-not-fat was not altered by rations fed, but the percentages of milk fat and protein were significantly higher (P<0.05) for Ration C and D than for Ration A.
